Patent Application
20120107428
Eusocial vespid wasps include several subfamilies, such as Polistinae, Vespinae, and Polybiinae from Vespidae (Hymenoptera: Vespidae), commonly referred to as paper wasps, yellowjackets, and hornets in North America. Ecologically speaking, paper wasps, yellowjackets, and hornets are beneficial insects because they prey upon many pest insects that feed on agricultural crops, garden plants, and forests, especially during early and mid summer season. However, these social wasps can be a serious stinging hazard to humans and animals, particularly in defense of their colonies; but some species from the genera Vespula Thomson and Dolichovespula Rohwer come into frequent contact with people when scavenging for sugar-rich foods and animal carrion away from their nests. In recent years, paper wasps have caused serious problems in fruit orchards and vineyards by biting the fruit and causing scarring, which results in price devaluation and high populations of paper wasps pose a significant danger to harvesters.
Research efforts to develop control or management strategies for these pestiferous social wasps have focused on poison baits to reduce or eliminate wasps and larvae in the nests or on chemical attractants or food materials for traps to reduce foraging adult wasp populations (workers or queens). Combinations of pesticides and meats have been used to control the western yellowjacket, Vespula pensylvanica; the common yellowjacket, Vespula vulgaris (L.); and the German yellowjacket Vespula germanica (F.). Although protein-based poison baits showed some regional success, they are not extensively used because of their expense, the short length of time that they are attractive, and significant side-effects on the non-target species and environment. Moreover, there is only one yellowjacket poison-bait product, Alpine Onslaught® Microencapsulated Esfenvalerate, registered in the USA. On the other hand, chemical attractants, including heptyl butyrate and acetic acid plus isobutanol among others, which are useful in trapping and monitoring vespid wasps, have been reported in several patents and scientific publications. Commercial traps baited with these synthetic attractants have been promoted and used for years as effective tools for monitoring or controlling the vespid wasps.
In contrast to the intensive work and significant progress on the attractants and poison-baits, which target wasp population reduction (an indirect protection measure), little or no research effort has been made on developing direct protection tactics, namely, wasp repellents. U.S. Pat. No. 7,744,280 discloses a wasp repellent device (a polypropylene bag) mimicking the aerial yellowjacket/hornet nest that reportedly repels hornets or yellowjackets. Unfortunately, neither the patents nor the academic literature appear to provide any bioassay data or scientific evidence to support these claims. In fact, most of the yellowjacket species in North America build their nests underground and the few species that build their nests aerially, such as Dolichovespula arenaria, D. maculata, and D. norvegicoides plus Vespa crabro, normally hide them in the tree branches, tree holes, or under or behind some human-made structures. These nesting behaviors raise strong doubts on the visual repellency effect of artificial nests. U.S. Patent Application Publication No. 2008/0305125 reports a series of complex chemical compositions/formulations for topical cosmetic use as wasp repellents that include one or more of 3-(N-n-butyl-N-acetylamino)propionate, dihydronepetalactone, and extract of catmint, and at least one compound selected from certain perfume ingredients (>60 chemicals or oils). Unfortunately, the application does not describe testing the repellency of the exemplified gel formulation (consisting of more than 15 ingredients) alone; instead, the application describes testing the feeding detergency of a combination of the gel formulation with a known mosquito repellent, 15% IR 3535, in comparison with two commercial mosquito repellents, mosquito spray (p-Menta-3,8-diol) and Autan Active Spray (with 20% Icaridin), and a blank control. Since 15% IR 3535 alone was not tested in the bioassay experiment, one could not determine if the 2-min repellency (or feeding deterrency) effect on Vespula vulgaris caused by the binary combination was due to the behavioral activity of the gel formulation or 15% IR 3535 or the combination. Assuming the gel formulation was responsible for the observed wasp repellency (or feeding deterrence), it is still unknown which individual chemical(s) or partial mixtures or full blend of the more than 15 ingredients in this formulation were responsible for the repellent effect. Many of the chemicals on the disclosed “kitchen sink” list probably have no repellency effect at all. In fact, some of the chemicals on the list, such as linalool, benzyl alcohol, and terpineol have been reported as part of a wasp attractant system. To the best of the inventors' knowledge, there are no conclusively confirmed spatial repellents for any pestiferous vespid wasps so far.
Methods for controlling insects are disclosed. In some embodiments, a method for repelling an insect comprises: releasing into a space a repellent composition comprising at least one of (a) or (b): (a) a first essential oil selected from the group consisting of lemongrass oil, ylang ylang oil, clove oil, geranium oil, rosemary oil, spearmint oil, wintergreen oil, lavender oil, sage oil, anise oil, fennel oil, citronella oil, peppermint oil, pennyroyal oil, thyme oil, Roman chamomile oil, and patchouli oil, or any combination thereof; (b) a second essential oil comprising at least one compound selected from the group consisting of I-menthone, P-menthone, eugenol, E-citral, Z-citral, pulegone, α/β-thujones (that is, a mixture of α-thujone and β-thujone), methyl benzoate, d-carvone, methyl salicylate, E/Z-nepetalactone, Z/E-nepetalactone, 3-octanol, benzyl acetate, citronellal, an isomer thereof, or any combination thereof, wherein the compound is a major constituent of the second essential oil, wherein the repellent composition is comprised in a controlled release device having at least one aperture configured to achieve a desired rate of release of the repellent composition in a volatilized state into the space; and repelling from the space an insect belonging to the insect family Vespidae, wherein each essential oil of (a) or (b) acts to repel the insect. A mixture may exclude any one or more of these oils.
Another method for repelling insects comprises releasing into a space a repellent composition comprising at least one synthetic compound selected from the group consisting of I-menthone, P-menthone, eugenol, E-citral, Z-citral, pulegone, α/β-thujones, methyl benzoate, d-carvone, methyl salicylate, E/Z-nepetalactone, Z/E-nepetalactone, 3-octanol, benzyl acetate, citronellal, an isomer thereof, or any combination thereof; wherein the repellent composition is comprised in a controlled release device having at least one aperture configured to achieve a desired rate of release of the repellent composition in a volatilized state into the space; and repelling from the space an insect belonging to the insect family Vespidae, wherein each synthetic compound acts to repel the insect. A mixture may exclude any one or more of these compounds.
In the methods disclosed above, the methods may further include releasing into the space any other essential oil(s), not included in the first embodiment but containing any identified repellent compounds disclosed in the second embodiment as major constituent(s).
In the embodiments disclosed above, the formulated repellent essential oils or synthetic compounds can be applied on or in the vicinity of a human or another animal, on or in the vicinity of any properties or structures, or during human activities (events) to repel or deter the target insects.
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
Plant essential oils are one of the major types of botanical products used for insect control. These oils are major sources of highly active and potent metabolites with strong impacts on insect biology, behavior, and physiology. In addition, essential oils have low environmental persistence and mammalian toxicity. More relevantly, they are normally available in large quantities at reasonable prices due to their widespread use as fragrance an food flavors. Essential oils are typically derived by steam distillation from many plant families. They mainly include complex blends of hydrocarbons (monoterpenes and sequiterpenes) and oxygenated compounds such as alcohols, esters, ethers, aldehydes, ketones, lactones, phenols, phenol ethers, and alkaloids. Many essential oils have been shown to have high repellency against various biting insects/arthropods (such as mosquitoes, sand flies, ticks, and other health related pests), and several agricultural pests (such as the green peach aphid, Myzus persicae; onion aphid, Neotoxoptera formosana; maize weevil, Sitophilus zeamais; red flour beetle, Tribolium castaneum; two spotted spider mite, Tetranychus urticae; Resselivella oculiperda; and Japanese beetle, Popillia japonica Newman). Owing to their aromatic properties, the inventors believe that essential oils would also be a good source of natural repellents for stinging social wasps, namely, yellowjackets, paper wasps, and hornets. Furthermore, combinations of repellents (and their release devices) with known attractants (and traps) in a “push-pull” fashion may strengthen the capacity to combat the serious public health problems against the pestiferous vespid wasps.
Unwittingly, many people might engage in activities that include sources which release compounds that attract insects. When people dine outdoors, sugar and protein containing foods are common sources of compounds that, when emitted into the air, can result in the attraction of unwanted wasps and similar flying insects. It would be desirable to provide protection against insects to persons engaging in such activities. In other circumstances, vespid wasps may happen to build their nests in proximity to areas where people might be present, such as along walkways, in paths, in trees, or on the grounds of nearby homes or businesses. Close proximity of persons to wasps might evoke a defensive reaction from the wasps. Accordingly, it would be desirable to repel insects from certain spaces or surfaces. The present disclosure can advantageously provide such protection. Space as used herein refers to any areas including air space, ground space and in or on things, plants, humans, or other animals. The present disclosure advantageously provides for such uses as well as others. In one embodiment, the present disclosure describes a method for controlling insects. Controlling insects, as used herein, means to change a behavior of the insect, such as to cause the insect to be repelled, for example.
The present application describes field tests of the potential repellency of some representative essential oils against several major vespid wasps using attractant-baited traps and identifies antennally active compounds from the behaviorally repellent essential oils, which are likely responsible for the repellency, using headspace sampling (SPME), gas chromatographic (GC)—electroantennographic detection (EAD), and GC-mass spectrometry (MS) to determine behavioral activity (potential repellency) of these EAD-active compounds in the field using attractant-baited traps. It should also be appreciated that any essential oil not specifically listed herein, but that, nevertheless, contains any of the identified compounds as a major constituent therein, is included within the scope of this disclosure. As used herein, “major constituent” refers to a constituent that is present in greater than 5 wt % of the total volatiles.
The behaviorally repellent essential oils (individually or in combination) or their EAD-active and behaviorally repellent synthetic compounds and their isomers (individually or in combination) may be formulated alone or with other ingredients and released at an effective amount from suitable devices or dispensers to provide a spatial attraction-inhibitor/repellent or topical repellent composition for controlling or repelling various species of pestiferous vespid wasps. The essential oils or compounds alone may provide repellency to the insects. Examples of the application of the essential oils or compounds for spatial attraction-inhibition/deterrence/repellency along with topical repellency include, but are not limited to: for use as a spatial repellent or attraction-inhibitor, the methods may include releasing into a space where one wants to provide such inhibiting or deterring or repelling effect or, in the case of an individual, dispensing or applying onto a protection device, such as a dispenser for a human target or for another animal, at least one essential oil as described herein, or at least one synthetic compound, or combinations thereof, as described herein. The method may also include releasing into the space or surface any other essential oil(s) not listed but containing any identified repellent compound(s) as a major constituent.
In some embodiments, employment of a repellent composition and a controlled release device provides repellency. Such devices are described herein, and it is noted that selection of a device may enhance the effects of the repellent composition as adjusting and metering the concentration of the volatilized repellent composition per cubic meter of air helps to achieving maximum repellency. Factors affecting device selection include the insect targeted, time of year (as temperature correlates to a volatile's release rate), environment (e.g., closed space, open space, calm day, windy day, low humidity environment (e.g., Arizona), and high humidity environment (e.g., New York)). Use of a controlled release device in combination with a repellent composition may provide repellency effects that are greater than use of the repellent composition alone.
The repellent essential oils or synthetic compounds disclosed herein may be formulated into and released at an effective amount from various suitable devices or dispensers with their formulations in either the form of a liquid, a solid, a gel, or any combination thereof as a spatial or topical deterrent, a repellent, or an attraction-inhibitor composition. As the active ingredients, the essential oil(s) or compound(s) may be the only active ingredient in such formulation. Other ingredients may be added for controlling volatility or to provide fragrance, for example. An “active” ingredient is the material responsible for repellency of the insects.
Also provided is a method for repelling an insect, comprising: releasing into a space a repellent composition comprising at least one of (a) or (b): (a) a first essential oil selected from the group consisting of lemongrass oil, ylang ylang oil, clove oil, geranium oil, rosemary oil, spearmint oil, wintergreen oil, lavender oil, sage oil, anise oil, fennel oil, citronella oil, peppermint oil, pennyroyal oil, thyme oil, Roman chamomile oil, and patchouli oil, or any combination thereof; (b) a second essential oil comprising at least one compound selected from the group consisting of I-menthone, P-menthone, eugenol, E-citral, Z-citral, pulegone, α/β-thujones, methyl benzoate, d-carvone, methyl salicylate, E/Z-nepetalactone, Z/E-nepetalactone, 3-octanol, benzyl acetate, citronellal, an isomer thereof, or any combination thereof, wherein the compound is a major constituent of the second essential oil, wherein the repellent composition is comprised in a controlled release device having at least one aperture configured to achieve a desired rate of release of the repellent composition in a volatilized state into the space; and repelling from the space an insect belonging to the insect family Vespidae, wherein each essential oil of (a) or (b) acts to repel the insect. In some embodiments, the repellent composition comprises two or more first essential oils of (a). In some embodiments, the repellent composition comprises two or more second essential oils of (b). In some embodiments, the repellent composition comprises at least one first essential oil of (a) and at least one second essential oil of (b).
In any embodiment herein, a repellent composition may further comprise at least one synthetic compound selected from the group consisting of I-menthone, P-menthone, eugenol, E-citral, Z-citral, pulegone, α/β-thujones, methyl benzoate, d-carvone, methyl salicylate, E/Z-nepetalactone, Z/E-nepetalactone, 3-octanol, benzyl acetate, citronellal, an isomer thereof, or any combination thereof. These compounds were identified from the repellent essential oils disclosed above and show strong antennal responses by various social wasp species that are largely responsible for the repellency of the essential oils. Any synthetic isomer of the above disclosed compounds may also be used in any embodiment herein, such as a skeletal isomer or a position isomer, or a stereoisomer.
A controlled release device may comprise a polymeric sheet having a means for permitting the repellent composition in a volatilized state to pass therethrough. The polymeric sheet may comprise a plurality of laminae. An innermost lamina of the plurality of lamina may be semi-permeable such that the repellent composition in a volatilized state can pass through the innermost lamina. In some embodiments, the means for permitting the repellent composition to pass therethrough comprises a plurality of micro-perforations. In some embodiments, the polymeric sheet further comprises an innermost lamina and wherein at least some of the plurality of micro-perforations do not penetrate an innermost lamina of the polymeric sheet. A method may further comprise placing the controlled release device outdoors. For example, a controlled release device may be placed on or near (e.g., within 10 feet) of a target selected from the group consisting of the eaves of a residential building, a commercial building, a fence, a picnic table, a barbeque site, a garbage bin or area, a playground, a recreation park, a tree, a path, a walkway, a deck, a pool, and a campsite to prevent an insect from sensing or approaching the target.
In some embodiments, an insect is selected from the group consisting of paper wasps, yellowjackets, and hornets, or any combination thereof. Non-limiting examples of insects include Polistes annularis; P. apaches; P. aurifer (Golden Paper Wasp); P. bellicosus; P. carolina; P. dominula (European Paper Wasp); P. dorsalis; P. exclamans; P. fuscatus; P. metricus; P. perplexus); Vespula acadica Sladen; V. atropilosa Sladen (Prairie Yellowjacket); V. austriaca Panzer; V. consobrina Saussure (Blackjacket); V. flavopilosa Jakobson (Transition Yellowjacket); V. germanica Fabricius (German Yellowjacket); V. maculifrons Buysson (Eastern Yellowjacket); V. pensylvanica Saussure (Western Yellowjacket); V. squamosa Drury (Southern Yellowjacket); V. sulphurea Saussure (California Yellowjacket); V. vidua Saussure (Forest Yellowjacket); V. vulgaris Linnaeus (Common Yellowjacket); Dolichovespula arenaria Fabricius (Aerial Yellowjackets); D. maculata Linnaeus (Bald-faced Hornet); D. norvegicoides Sladen (Arctic Yellowjacket); Vespa crabro Linnaeus (European Hornet); V. mandarinia Smith (Asian Giant Hornet); and V. orientalis Linnaeus (Oriental Hornet). Any combination of these insects is contemplated.
Also provided is a method for repelling insects, comprising: releasing into a space a repellent composition comprising at least one synthetic compound selected from the group consisting of I-menthone, P-menthone, eugenol, E-citral, Z-citral, pulegone, α/β-thujones, methyl benzoate, d-carvone, methyl salicylate, E/Z-nepetalactone, Z/E-nepetalactone, 3-octanol, benzyl acetate, citronellal, an isomer thereof, or any combination thereof; wherein the repellent composition is comprised in a controlled release device having at least one aperture configured to achieve a desired rate of release of the repellent composition in a volatilized state into the space; and repelling from the space an insect belonging to the insect family Vespidae, wherein each synthetic compound acts to repel the insect. A repellent composition may further comprise at least one of (a) or (b): (a) a first essential oil selected from the group consisting of lemongrass oil, ylang ylang oil, clove oil, geranium oil, rosemary oil, spearmint oil, wintergreen oil, lavender oil, sage oil, anise oil, fennel oil, citronella oil, peppermint oil, pennyroyal oil, thyme oil, Roman chamomile oil, and patchouli oil, or any combination thereof; (b) a second essential oil comprising at least one compound selected from the group consisting of I-menthone, P-menthone, eugenol, E-citral, Z-citral, pulegone, α/β-thujones, methyl benzoate, d-carvone, methyl salicylate, E/Z-nepetalactone, Z/E-nepetalactone, 3-octanol, benzyl acetate, citronellal, an isomer thereof, or any combination thereof, wherein the compound is a major constituent of the second essential oil. In some embodiments, the repellent composition comprises two or more first essential oils of (a). In some embodiments, the repellent composition comprises two or more second essential oils of (b). In some embodiments, the repellent composition comprises at least one first essential oil of (a) and at least one second essential oil of (b). In such methods, the controlled release device may be any device described herein, and may be placed in any setting described herein. Insects may be any insect or combination of insects as described herein.
Also provided is a package containing a quantity of a repellent composition, comprising: a stick pack comprising a polymeric sheet having a means for permitting a repellent composition volatile to pass therethrough; and a quantity of volatilizing repellent composition disposed in the stick pack, wherein the repellent composition is substantially in a non-volatilized state; wherein the stick pack is configured to achieve a desired rate of release of repellent composition volatiles though the stick pack. The repellent composition may comprise at least one of (a) or (b): (a) a first essential oil selected from the group consisting of lemongrass oil, ylang ylang oil, clove oil, geranium oil, rosemary oil, spearmint oil, wintergreen oil, lavender oil, sage oil, anise oil, fennel oil, citronella oil, peppermint oil, pennyroyal oil, thyme oil, Roman chamomile oil, and patchouli oil, or any combination thereof; (b) a second essential oil comprising at least one compound selected from the group consisting of I-menthone, P-menthone, eugenol, E-citral, Z-citral, pulegone, α/β-thujones, methyl benzoate, d-carvone, methyl salicylate, E/Z-nepetalactone, Z/E-nepetalactone, 3-octanol, benzyl acetate, citronellal, an isomer thereof, or any combination thereof, wherein the compound is a major constituent of the second essential oil. A repellent composition may comprise at least one synthetic compound selected from the group consisting of I-menthone, P-menthone, eugenol, E-citral, Z-citral, pulegone, α/β-thujones, methyl benzoate, d-carvone, methyl salicylate, E/Z-nepetalactone, Z/E-nepetalactone, 3-octanol, benzyl acetate, citronellal, an isomer thereof, or any combination thereof.
Further provided is a repellent composition stick pack for controlling the rate of release of volatiles of a repellent composition comprising: a polymeric sheet having a plurality of micro-perforations, the stick pack defining a volume; and a quantity of repellent composition disposed in the volume; wherein the plurality of micro-perforations are sized and configured to prevent the quantity of repellent composition from escaping from the stick pack in a non-volatilized state and to achieve a desired rate of escape of volatilized repellent composition from the stick pack. The polymeric sheet may comprise a plurality of laminae. An innermost lamina of the plurality of laminae may be semi-permeable such that the repellent composition in the volatilized state can pass through the innermost lamina. In some embodiments, the repellent composition comprises at least one of (a) or (b): (a) a first essential oil selected from the group consisting of lemongrass oil, ylang ylang oil, clove oil, geranium oil, rosemary oil, spearmint oil, wintergreen oil, lavender oil, sage oil, anise oil, fennel oil, citronella oil, peppermint oil, pennyroyal oil, thyme oil, Roman chamomile oil, and patchouli oil, or any combination thereof; (b) a second essential oil comprising at least one compound selected from the group consisting of I-menthone, P-menthone, eugenol, E-citral, Z-citral, pulegone, α/β-thujones, methyl benzoate, d-carvone, methyl salicylate, E/Z-nepetalactone, Z/E-nepetalactone, 3-octanol, benzyl acetate, citronellal, an isomer thereof, or any combination thereof, wherein the compound is a major constituent of the second essential oil. In some embodiments, the repellent composition comprises at least one synthetic compound selected from the group consisting of I-menthone, P-menthone, eugenol, E-citral, Z-citral, pulegone, α/β-thujones, methyl benzoate, d-carvone, methyl salicylate, E/Z-nepetalactone, Z/E-nepetalactone, 3-octanol, benzyl acetate, citronellal, an isomer thereof, or any combination thereof.
Also provided is a method for controlling the rate of release of volatiles of a repellent composition comprising: forming a stick pack comprising a polymeric sheet having an inner layer that is permeable to volatiles of the repellent composition and an outer layer that is substantially impermeable to volatiles of the repellent composition; removing a portion of the outer layer defined by a closed contour to define a window portion; providing a quantity of the repellent composition into the stick pack, wherein the repellent composition will gradually volatilize during use; and sealing an end portion of the stick pack such that the quantity of repellent composition is retained in the stick pack. An inner layer may comprise a plurality of micro-perforations therethrough. A repellent composition may comprise at least one of (a) or (b): (a) a first essential oil selected from the group consisting of lemongrass oil, ylang ylang oil, clove oil, geranium oil, rosemary oil, spearmint oil, wintergreen oil, lavender oil, sage oil, anise oil, fennel oil, citronella oil, peppermint oil, pennyroyal oil, thyme oil, Roman chamomile oil, and patchouli oil, or any combination thereof; (b) a second essential oil comprising at least one compound selected from the group consisting of I-menthone, P-menthone, eugenol, E-citral, Z-citral, pulegone, α/β-thujones, methyl benzoate, d-carvone, methyl salicylate, E/Z-nepetalactone, Z/E-nepetalactone, 3-octanol, benzyl acetate, citronellal, an isomer thereof, or any combination thereof, wherein the compound is a major constituent of the second essential oil. A repellent composition may comprise at least one synthetic compound selected from the group consisting of I-menthone, P-menthone, eugenol, E-citral, Z-citral, pulegone, α/β-thujones, methyl benzoate, d-carvone, methyl salicylate, E/Z-nepetalactone, Z/E-nepetalactone, 3-octanol, benzyl acetate, citronellal, an isomer thereof, or any combination thereof.
Further provided is a method for controlling the rate of release of volatiles of a repellent composition comprising: forming a stick pack comprising a polymeric sheet having an inner layer that is permeable to volatiles of the repellent composition and an outer layer that is substantially impermeable to volatiles of the repellent composition, wherein the outer layer is removably affixed to the inner layer; cutting a closed contour through the outer layer to define a peel-away portion; providing a quantity of the repellent composition into the stick pack, wherein the repellent composition will gradually volatilize during use; and sealing an end portion of the stick pack such that the quantity of repellent composition is retained in the stick pack. In some embodiments, the inner layer comprises a plurality of micro-perforations therethrough. The inner layer may comprise a plurality of laminae. A depth of the plurality of micro-perforations may be configured such that at least some of the plurality of micro-perforations do not penetrate an innermost lamina. In some embodiments, the closed contour is cut by die cutting.
The essential oils and synthetic compounds of the disclosed methods are volatile, and, thus, one mode of application is to provide the essential oils or compounds in a form that is freely volatile. However, it is within the scope of this disclosure to use the compounds in a manner such that they may be bound to materials that reduce the volatility and slowly release the active repellent compositions.
The repellent essential oils and synthetic compounds disclosed herein are readily available from many commercial chemical supply stores. Synthetic, when used to describe the compounds, means that compounds were purified from a natural source, manufactured or synthesized. Natural sources of these compounds include, but are not limited to, the essential oils: clove oil (Myrtaceae), lemongrass oil (Poaceae), ylang ylang oil (Annonaceae), spearmint oil (Lamiaceae), wintergreen oil (Ericaceae), sage oil (Lamiaceae), rosemary oil (Lamiaceae), geranium oil (Geraniaceae), lavender oil (Lamiaceae), anise oil (Apiaceae), fennel seed oil (Apiaceae), citronella oil (Poaceae), peppermint oil (Lamiaceae), pennyroyal oil (Lamiaceae), thyme oil (Lamiaceae), Roman chamomile oil (Asteraceae), and patchouli oil (Lamiaceae). Methods of isolating these compounds from natural sources are well-known in the art.
Insects include eusocial vespid wasps from the family Vespidae (order: Hymenoptera); the subfamily Polistinae; the subfamily Polybiinae; the subfamily Vespinae; the genera Polistes Latreille; the genera Mischocyttarus Saussure; the genera Brachygastra Perty; the genera Polybia Lepeletier; the genera Ropalidia Guérin-Méneville; the genera Vespula Thomson; the genera Dolichovespula Rohwer; the genera Vespa Linnaeus; any wasp species, such as paper wasps (e.g., Polistes annularis; P. apaches; P. aurifer (Golden Paper Wasp); P. bellicosus; P. carolina; P. dominula (European Paper Wasp); P. dorsalis; P. exclamans; P. fuscatus; P. metricus; P. perplexus;); such as yellowjackets (e.g., Vespula acadica Sladen; V. atropilosa Sladen (Prairie Yellowjacket); V. austriaca Panzer; V. consobrina Saussure (Blackjacket); V. flavopilosa Jakobson (Transition Yellowjacket); V. germanica Fabricius (German Yellowjacket); V. maculifrons Buysson (Eastern Yellowjacket); V. pensylvanica Saussure (Western Yellowjacket); V. squamosa Drury (Southern Yellowjacket); V. sulphurea Saussure (California Yellowjacket); V. vidua Saussure (Forest Yellowjacket); V. vulgaris Linnaeus (Common Yellowjacket); Dolichovespula arenaria Fabricius (Aerial Yellowjackets); D. maculata Linnaeus (Bald-faced Hornet); D. norvegicoides Sladen (Arctic Yellowjacket); such as hornets Vespa crabro Linnaeus (European Hornet); V. mandarinia Smith (Asian Giant Hornet); V. orientalis Linnaeus (Oriental Hornet); or any wasp species. In any embodiment, any one or more family, subfamily, genus, or species may be employed. In any embodiment, any one or more family, subfamily, genus, or species may be specifically excluded.
In the embodiments disclosed herein, the one or more insects may include any insect including, but not limited to, insects from the family Vespidae of the order Hymenoptera, and any paper wasp species, yellowjacket species, or hornet species. An embodiment may exclude any one or more of these species. In some embodiments, any one or more of the repellent essential oils and any one or more of the synthetic compounds can be combined to repel a single insect species selected from any insect species belonging to the family Vespidae. In another embodiment, any one or more of the repellent essential oils and any one or more of the synthetic compounds can be combined to repel a subset of insect species selected from the insect species belonging to the family Vespidae. In another embodiment, any one or more of the repellent essential oils and any one or more of the synthetic compounds can be combined to repel a single insect species selected from any insect species belonging to the subfamily Polistinae. In another embodiment, any one or more of the repellent essential oils and any one or more of the synthetic compounds can be combined to repel a subset of insect species selected from the insect species belonging to the subfamily Polistinae. In another embodiment, any one or more of the repellent essential oils and any one or more of the synthetic compounds can be combined to repel a group of insects, including paper wasps, yellowjackets, and hornets. In the above embodiments, any one or more of the repellent essential oils and any one or more of the synthetic compounds can be combined to repel a targeted species of insect or a subset of insect species, while not repelling other species outside the target.
Any essential oil or synthetic compound may comprise about, at most about, or at least about a weight percent of 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21, 21.5, 22, 22.5, 23, 23.5, 24, 24.5, 25, 25.5, 26, 26.5, 27, 27.5, 28, 28.5, 29, 29.5, 30, 30.5, 31, 31.5, 32, 32.5, 33, 33.5, 34, 34.5, 35, 35.5, 36, 36.5, 37, 37.5, 38, 38.5, 39, 39.5, 40, 40.5, 41, 41.5, 42, 42.5, 43, 43.5, 44, 44.5, 45, 45.5, 46, 46.5, 47, 47.5, 48, 48.5, 49, 49.5, 50, 50.5, 51, 51.5, 52, 52.5, 53, 53.5, 54, 54.5, 55, 55.5, 56, 56.5, 57, 57.5, 58, 58.5, 59, 59.5, 60, 60.5, 61, 61.5, 62, 62.5, 63, 63.5, 64, 64.5, 65, 65.5, 66, 66.5, 67, 67.5, 68, 68.5, 69, 69.5, 70, 70.5, 71, 71.5, 72, 72.5, 73, 73.5, 74, 74.5, 75, 75.5, 76, 76.5, 77, 77.5, 78, 78.5, 79, 79.5, 80, 80.5, 81, 81.5, 82, 82.5, 83, 83.5, 84, 84.5, 85, 85.5, 86, 86.5, 87, 87.5, 88, 88.5, 89, 89.5, 90, 90.5, 91, 91.5, 92, 92.5, 93, 93.5, 94, 94.5, 95, 95.6, 97, 97.5, 98, 98.5, 99, or 99.5% or more, but less than 100%, of a composition, or any range derivable therein.
In any embodiment herein, a composition may comprise a synergistic amount of one or more essential oils, one or more synthetic compounds, or any combination thereof, to provide a synergistic repellency, deterrent, or attraction-inhibitory effect. As used herein, a “synergistic amount” refers to an amount that produces greater than additive effects.
Any embodiment herein may comprise, consist essentially of, or consist of components, ingredients, steps, etc. With respect to “consist essentially of,” such embodiments are drawn to the specified components, ingredients, steps, etc., and those that do not materially affect the basic and novel characteristics of the claimed invention. Non-limiting examples of those that do not materially affect the basic and novel characteristics of the claimed invention include antioxidants (e.g., butylated hydroxytoluene, or BHT) and vegetable oils as inert controlled release agents. With respect to “consist of,” such embodiments are drawn to the specified components only.
The dispensing of such natural essential oils or synthetic compounds may be by way of evaporation or volatilization of the active essential oils or compounds from a device with either a controlled release or a passive release method, such as dispersion by an aerosol or powder that can be scattered on the ground, and the like.
There can also be provided a controlled release device that is used to control the release rate of volatilization of the essential oil(s) or the synthetic compound(s). A release device can be a container having a space therein to house a material onto which one or more of the essential oils or one or more of the compounds is impregnated. The material typically has sufficient free void space to take in or absorb a quantity of essential oils or compounds sufficient to achieve a desired effect (e.g., repellency). Suitable materials can be fibrous, porous, solids, or flexible materials. Suitable materials may include such absorbent materials such as paper, porous plastics, absorbent minerals, carbon, and the like. The release device can have an opening on the outer surface thereof to permit the vapors emitted from the essential oil or oils or compounds to escape the device. Preferably, the device includes means for closing the opening, such as when the device is not in use, and, more preferably, the size of the opening can be made adjustable to allow the user of the device control over whether to emit more or less of the vapors, including complete shut off. The release device can vary in its shape or size to accommodate short periods of efficacy or long periods of efficacy. Devices can come in sizes made to last days or weeks by altering the amount of essential oils and compounds that are loaded into the absorbent material.
The material within the device can be replaced with a new material when the essential oils or synthetic compounds have been depleted. To this end, absorbent materials may come preloaded with the essential oils and compounds and made separately available to be placed in the device by the user. Additionally, the device can be made to accept differing sizes of the absorbent material to allow selecting short or long periods of efficacy. Materials having different essential oils or compounds can be preloaded and made available to a user, such that some essential oils or compounds can be more effective toward one kind of insect. The package may indicate which insect is repelled so that the user is able to change materials, but is only required to purchase one device. This permits a user to tailor the device to a particular length of use and for a particular insect. The devices can be made from plastics or other suitable materials of construction. Devices can be injection molded. Devices can also be wearable by humans as well as animals, such as pets, including, but not limited to dogs and cats. To such end, a release device may include a clip or other means of attachment, such as hook and loop fasteners, a pin, a belt loop, and the like. Other forms of release devices made for the home or an exterior location can vary in their shape or size to fit different settings, such as incorporating the compounds into ornaments to be inconspicuously placed in indoor or outdoor locations, or can be used for dual purposes, such as decorations having insect-repellent properties, and for use in buildings or vehicles.
Furthermore, these repellent devices or dispensing formulations (solids—powders, impregnated plastics, impregnated fibers; or liquids—sprays, aerosols; or gels—creams) can be easily applied outdoors, that is, to outdoor settings such as the eaves of building structures (residential buildings, such as homes; commercial buildings; barns; greenhouses), fences, picnic tables, barbeque sites, garbage bins/areas, playgrounds, recreation parks, trees, paths, walkways, decks, pools, or campsites to prevent vespid wasps (e.g., yellowjackets, paper wasps, and hornets) from sensing or approaching these targets and activities. Such repellent formulations can also be deployed (near the target activity or event centers to push the wasps away) in cooperation with attractants-baited traps (set up around the target activities or events to pull the wasps away from the targets) for these social wasps in a push-pull tactic, which would likely enhance the pest control efficacy against these pestiferous social wasps. Alternatively, the essential oils or synthetic compounds disclosed herein can also be absorbed on a porous substrate or combined with a polymeric gel or formulated into creams, lotions, aerosols, or other suitable formulations for topical application. For repelling pestiferous social wasps from a subject such as a human, a method may comprise the step of applying to the skin of the subject a repellent in an effective dose of at least one essential oil selected from the following essential oils: clove oil, lemongrass oil, ylang ylang oil, spearmint oil, wintergreen oil, sage oil, rosemary oil, geranium oil, lavender oil, anise oil, fennel seed oil, citronella oil, peppermint oil, pennyroyal oil, thyme oil, Roman chamomile oil, patchouli oil; or at least one EAD-active and behaviorally repellent synthetic compound from following candidate chemicals such as I-menthone, P-menthone, eugenol, E-citral, Z-citral, pulegone, α/β-thujones, methyl benzoate, d-carvone, methyl salicylate, E/Z-nepetalactone, Z/E-nepetalactone, 3-octanol, benzyl acetate, citronellal, or any combination thereof. The method may also include releasing into a space or surface any other essential oil(s) not listed but containing any identified repellent compound(s) as a major constituent.
A particular embodiment of a controlled release device is a stick pack including a repellent composition in accordance with the present invention will now be described with reference to the FIGURES, wherein like numbers indicate like parts.
As discussed below, the properties and configuration of the multiple layers for stick packs 100 cooperatively restrict and control the release rate of volatiles from a repellent composition packaged in the stick pack 100. In particular, the designer may select the materials and certain characteristics of the layers used for the sheet of material to achieve a desired volatile release rate. For example, the layer material properties (e.g., the porosity of the material to the selected repellent composition volatiles), the thickness of the layers, the characteristics of optional apertures, such as micro-perforations (e.g., number, density, size, depth, and shape).
In the embodiment of
It should be appreciated that although the repellent composition 120 is illustrated in an idealized powder or particulate form in
It should be readily appreciated that the rate of release of the volatiles 122 will depend in part on the characteristics of the micro-perforations 110. For example, the rate of release may depend on micro-perforation parameters such as (1) the number of perforations; (2) the size or distribution of sizes of the perforations; (3) the spacing and pattern of the perforations; (4) the shape of the perforations (e.g., elongate, star-shaped, circular); (5) the depth of the perforations (e.g., extending partially through the substrate); and (6) any blockage of the perforations. The designer or the user, therefore, have a number of parameters that may be used to control the rate of release of volatiles 122.
For example, the designer may select the size and number of micro-perforations 110 to accommodate a particular repellent composition 120, to achieve a desired release rate. A repellent composition 120 having a low volatility may require more and larger perforations than one with a repellent composition that is highly volatile. In another example, different configurations of micro-perforations 110 may be available, depending on the anticipated environmental conditions (e.g., temperature, humidity) for the expected use of the repellent composition 120. For example, one configuration of micro-perforations in a repellent composition stick pack 100 may be suitable when lower temperatures are expected, and a different configuration may be suitable at higher temperatures. A family of repellent composition stick packs 100 may be made available to users, who will then select the particular stick pack 100 that suits their application. Optionally, a blocking element (not shown), for example, a strip of adhesive, a sleeve, or the like, may be provided to selectively block some portion of the micro-perforations 110, to selectively adjust the rate of release of volatiles 122, for example to adjust for environmental conditions or to accommodate particular situations.
One or more of the laminae 131, 132, 133, 134 may also be selected to provide permeability to one or more repellent composition volatiles 122, providing an additional parameter to control the release rate of particular volatiles 122.
In
Therefore, it will be appreciated that a stick pack 100 may be designed to contain a plurality of different repellent compositions in a mixture or agglomeration, and to provide different release rates for each of the different repellent compositions.
A reservoir 206 of the desired repellent composition provides product to a stick pack machine 208 that fills and receives the sheet material 202 and forms the final stick pack 100 of repellent composition 120. The operation is controlled with a computer or stand-alone central processing unit (CPU) controller 210 that may be separate or integrated into the stick pack machine 208. The controller 210 is programmable to accommodate different sheet material 202 and repellent compositions 120, such that the system 200 may be operated to produce any number of different products.
A simplified flow chart 220 of a method in accordance with the present invention is shown in
The packaging for the stick pack 100 is fabricated 224, configured for the desired release rate of the volatiles, for example with micro-perforations or selected permeability properties. The selected repellent composition is deposited into the packaging or onto the sheet prior to sealing the package 226. The stick pack ends and longitudinal seam are sealed 228. Typically, the stick pack 100 is then sealed in an outer package 230, for example a foil pack or a plastic package, which is suitable for shipping and display. As an alternative or in addition, it is contemplated that a removable adhesive strip (not shown) may be placed over the micro-perforations, and removed prior to use.
Although the above described stick pack 100 is formed with a single compartment for the repellent composition 120, it is contemplated that the stick pack may be formed with multiple compartments.
Alternatively, the compartments 252 may be configured differently, for example to accommodate different repellent compositions 120. The multi-compartment stick pack 250 may therefore be readily designed to accommodate different repellent compositions, with the micro-perforations in each compartment 252 tailored to produce a desired rate of release of volatiles for each repellent composition.
Another exemplary embodiment of a repellent composition stick pack 280 in accordance with the present invention is illustrated in
Another exemplary embodiment of a repellent composition stick pack 300 in accordance with the present invention is illustrated in
In this embodiment, the inner layer 302 shown on the bottom in
The perimeter of the peal-away portions 304, 306 may be defined by die-cutting the outer layer 303, for example, wherein the die cut process does not extend through the inner layer 302, or by other means such as laser cutting or the like.
It will be appreciated that in this embodiment the stick pack 300 does not require a separate external packaging. Moreover, the user has great flexibility in controlling the release rate of the repellent composition contained therein, by selecting how much of the peel-away portions 304, 306 to remove. Accordingly, the stick packs in accordance with the present invention provide a mechanism for very precisely controlling the release rate of repellent compositions contained in the stick pack.
The use of the term “or” in the claims is used to mean “or” unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “or.”
Throughout this application, the term “about” is used to indicate that a value includes the standard deviation of error for the device or method being employed to determine the value. In any embodiment discussed in the context of a numerical value used in conjunction with the term “about,” it is specifically contemplated that the term about can be omitted.
Following long-standing patent law, the words “a” and “an,” when used in conjunction with the word “comprising” in the claims or specification, denotes one or more, unless specifically noted.
Headspace Sampling of Essential Oils and Collection of Insects
Headspace volatiles from greater than 10 types of essential oils (1 ml each in a closed 20 ml glass vial) were sampled via Solid-Phase Micro-Extraction (SPME) (CAR/PDMS, 85 μm, Supelco, Bellefonte, Pa.) for 20-30 sec before GC-EAD and GC-MS analyses.
Paper wasp [European paper wasp (Polistes dominulus) or golden paper wasp (P. aurifer)] and yellowjacket [Western yellowjacket (Vespula pensylvanica) or Bald-faced hornet (Dolichovespula maculata)] workers for electrophysiological study were collected from their nests and kept alive at 4° C. before testing.
GC-EAD/MS Analyses of Essential Oils
SPME samples of the various essential oils were injected splitless into a Varian CP-3800 GC equipped with a polar column (HP-INNOWAX; 30 m×0.53 mm×1.0 μm film thickness; Agilent Technologies, Wilmington, Del., USA) and a 1:1 effluent splitter that allowed simultaneous flame ionization detection (FID) and electroantennographic detection (EAD) of either a yellowjacket or paper wasp worker antenna to the separated volatile compounds. Helium was used as the carrier gas, and the injector and detector temperatures were 250° C. and 300° C., respectively. Column temperature was 50° C. for 1 min, rising to 240° C. at 10° C./min, and then held for 10 min. The outlet for the EAD was held in a humidified air stream flowing at 0.5 m/sec over the antennal preparation. EAD recordings were made using silver wire-glass capillary electrodes filled with Beadle-Ephrussi Ringer on freshly cut antennae. The antennal signals were stored and analyzed on a PC equipped with a serial IDAC interface box and the program EAD ver. 2.5 (Syntech, Hilversum, The Netherlands).
Antennally active compounds (FID peaks) in the SPME samples of essential oils were identified by GC-MS on an HP 6890 GC series coupled with an HP 5973 Mass Selective Detector using the same type of GC column and conditions as described above. Compounds were identified by comparison of retention times with those of authentic standards and with mass spectra of standards.
Chemical Standards and Essential Oils
The following authentic chemical standards for chemical identification or field trapping experiments were obtained from various commercial and noncommercial sources: 3-octanol (99%), 6-methyl-5-hepten-2-one (99%), α/β-thujone (65.4%), benzyl acetate (99%), d-carvone (98.5%), β-citronellol (95%), citronellal (85%), eugenol (98%), geraniol (98%), geranyl formate (FCC), geranyl acetate (98%), linalool (97%), methyl benzoate (99%), and methyl salicylate (99%) were obtained from Sigma-Aldrich Chemical (Milwaukee, Wis.); (−)-verbenone from Bedoukian Research Inc., Danbury, Conn.; α-terpineol (>90%), E/Z-citral (>90%), menthone (>96%), and pulegone (>96%) from Vigon International, Inc., East Stroudsburg, Pa.; 4-methylanisole (99%) and 4-terpineol (97%) from Alfa Aesar, Ward Hill, Mass.; 4-nonanone (98%) from Avocado; and 1,8-cineole (99%) from TCI America. E/Z-neptalactone (>95%) and Z/E-neptalactone (>95%) were isolated from catnip oil as described in U.S. Pat. No. 7,375,239.
The following essential oils tested were purchased from Lorann Oil, Inc. (Lansing, Mich.): anise oil, camphor oil, citronella oil, clove oil, eucalyptus oil, fennel seed oil, geranium oil, lavender oil, lemongrass oil, patchouli oil, pennyroyal oil, myrrh oil, Roman chamomile oil, rosemary oil, sage oil, spearmint oil, thyme oil, wintergreen oil, vetiver oil, and ylang ylang oil.
Field Trapping Experiments
Eleven field trapping experiments were carried out from late August to mid-October 2009 in residential and woody areas around Spokane, Wash., USA, mostly using the trap known by the designation Rescue® W•H•Y (except on one occasion that Rescue® Reusable Yellowjacket Traps were used for a natural food attractant; see below for details). The commercial W•H•Y trap has a top chamber and a bottom chamber and is described in U.S. Patent Application Publication No. 2009/0151228. The top chamber is baited with two attractants—one of which is a solid contained in a vial (2-methyl-1-butanol), and the other is a liquid mixed with water (acetic acid). The bottom chamber is baited with a liquid attractant (heptyl butyrate) poured onto a cotton pad. Separation of the two types of attractants (otherwise antagonistic to each other when released from the same chamber) in two chambers creates two focal attraction sources from one trap for different species of wasps, hornets, and yellowjackets. In order to test potential repellency of essential oils or EAD-active synthetic candidate compounds on different types of attractants, W•H•Y traps were baited with either a top attractant or a bottom attractant depending on the experiments. In a special occasion, the commercial Rescue® Reusable Yellowjacket Traps were each baited with 10 g of chopped bacon (loaded into a cartridge) as a natural protein food attractant. Traps were hung 1.5-2.0 m above the ground on either fences or tree branches ca. 5 m apart between each trap and at least 15 m between sets. For each trapping experiment, three sets of traps (i.e., three physical replicates of each treatment) were deployed with their initial trap positions within each set being randomized. To minimize positional effects and obtain more replications, wasp collections and trap re-randomization were carried out when 5-10 wasps were caught in the best traps. Each replicate lasted several days depending on wasp flight activity. Captured wasps were removed from the traps and kept in the zip-bags before returning to the laboratory for recording of the species, gender status, and catch. Repellent candidates (individuals or mixtures) were released from polyethylene bags (3×5 cm; with a fabric felt) with various thicknesses from 2-12 mil (see release rates listed in tables); they were employed inside the same trap chamber as the attractant.
Experiment 1 tested five individual essential oils (pennyroyal, lemongrass, peppermint, clove, and citronella) and two known mosquito repellents (i.e., major components of catnip oil), E/Z-nepetalactone and Z/E-nepetalactone plus a blank control against a mixture of attractant [acetic acid (AA) and 2-methyl-1-butanol (2 MB)] using the W•H•Y traps (both attractant and repellent candidates were released from the top chamber) from for eight consecutive days from August to early September. Experiment 2 tested nine individual essential oils (ylang ylang, vetiver, myrrh, patchouli, geranium, eucalyptus, camphor, spearmint, and wintergreen) plus a blank control against a mixture of attractant (AA+2 MB) using the W•H•Y traps (both attractant and repellent candidates were released from the top chamber) for eight consecutive days from late August to early September. Experiment 3 tested seven individual essential oils (Roman chamomile, sage, fennel seed, rosemary, thyme, anise, and lavender) plus a blank control against a mixture of attractant (AA+2 MB) using the W•H•Y traps (both attractant and repellent candidates were released from the top chamber) for eight consecutive days from late August to early September. Experiment 4 tested two essential oil mixtures (3EO-mix: clove, geranium, and lemongrass in ca. 1:1:1 ratio; and 4EO-mix: clove, geranium, lemongrass, and rosemary in ca. 1:1:1:1 ratio) plus a blank control against a mixture of attractant (AA+2 MB) using the W•H•Y traps (both attractant and repellent candidates were released from the top chamber) for 13 consecutive days in September; the essential oil mixtures alone without attractant were tested in the same experiment. Experiment 5 was similar to experiment 4, but heptyl butyrate was used as the attractant released from the bottom chamber of the W•H•Y traps and the repellent candidates (EO-mix) were also released from the same chamber during the same trapping period as in experiment 4. Experiment 6 also tested these same EO-mix treatments, but was against 10 g of chopped bacon (loaded into a cartridge) as a natural protein food attractant using the Reusable Yellowjacket Traps during the same trapping period as the previous two experiments (4 and 5).
In addition, the repellency of the essential oil mixture (3EO-mix; at 0 cm and 50 cm above the heptyl butyrate attractant) on the landing behavior of yellowjackets was field observed (as experiment 7) on a September day for roughly 1.5 hours in Spokane, Wash. This observation test was conducted in the sun by setting up in a line east to west four portable light gray folding tables (45.7×66.0×67.3 cm) in a level area of grass near a vineyard. These tables were placed approximately 3 m apart. Chairs were set up approximately 4 m away from the tables for the scientists conducting the observations. On each table a black lab support stand was used with a movable metal bar in the horizontal direction clamped to the support stand for placing a repellent PE-bag dispenser (2 ml of 3EO-mix) or blank PE-bag at either 0 cm or 50 cm above the attractant, heptyl butyrate. A white towel was used to cover the black base of the support stand to provide a uniform color. A circle felt pad (3.5 cm diameter) loaded with 3 ml of heptyl butyrate as attractant or left blank for a negative control in a Petri dish (9 cm diameter) was placed on the base of the stand. The four tested treatments included a blank control (no attractant, no repellent), an attractant alone, an attractant plus a repellent dispenser right above it (0 cm) and an attractant plus a repellent dispenser 50 cm above it. The treatments were started in random positions on the tables for the first replicate then re-randomized for the next three replicates in a Latin-square design. Each observation replicate was run for 15 minutes. During that time, the scientist in charge of that table would observe and record the number of yellowjackets or paper wasps that approached the table within 0.5 m, and those that landed on or made contact with the attractant.
Experiment 8 tested six EAD-active synthetic compounds identified from repellent essential oils: 1,8-cineole, 6-methyl-5-hepten-2-one, P/I-menthones, linalool, camphor, and geranyl formate against AA+2 MB as the attractant using W•H•Y traps for 13 consecutive days in September. Experiment 9 tested another six EAD-active synthetic compounds identified from repellent essential oils: β-citronellol, 4-terpineol, α-terpineol, E/Z-citral, (−)-verbenone, and eugenol against AA+2 MB as the attractant using W•H•Y traps for 13 consecutive days in September. Experiment 10 tested nine more EAD-active synthetic compounds identified from repellent essential oils: 3-octanol, citronellal, α/β-thujones, methyl benzoate, benzyl acetate, d-carvone, pulegone, geraniol, and methyl salicylate against AA+2 MB as the attractant using W•H•Y traps for 18 consecutive days from the end of September through mid-October. Experiment 11 tested an EAD-active synthetic compound, 4-methylanisole, identified from ylang ylang oil during late flight season (sixteen consecutive days in October; with very low wasp populations) against AA+2 MB as the attractant using W•H•Y traps.
Statistical Analysis
Trap catch data (number of wasps/trap/visit) and landing/approaching numbers were transformed by log (X+1) and the transformed means were analyzed by ANOVA, followed by the Duncan's multiple-range test (SPSS 16.0 for Windows) at α=0.05.
Field Bioassays of the Essential Oils
Twenty-one essential oils were tested in Experiments 1-3 against AA/2 MB as attractants from late August to early September. Seventeen essential oils (clove oil, pennyroyal oil, lemongrass oil, ylang ylang oil, spearmint oil, wintergreen oil, sage oil, rosemary oil, lavender oil, geranium oil, patchouli oil, citronella oil, Roman chamomile oil, thyme oil, fennel seed oil, anise oil, and peppermint oil) showed significant repellency on either yellowjackets [Vespula pensylvanica (ca. 90%), plus V. vulgaris, V. germanica, and Dolichovespula maculata] or paper wasps (mainly Polistes dominulus, plus a few of P. aurifer) or both to the attractant AA/2 MB (Tables 1-3; also see Table 11 for summary). Clove oil, lemongrass oil, ylang ylang oil, spearmint oil, wintergreen oil, sage oil, rosemary oil, geranium oil, and lavender oil at 30-45 mg/day releases almost blocked the attraction of these vespid wasps to their AA/2 MB attractants (Tables 1-3; also see Table 11 for summary). Two known mosquito repellents from the catnip oil, E/Z-nepetalactone and Z/E-nepetalactone, also showed partially significant repellency on yellowjackets and paper wasps, with E/Z-nepetalactone being more significant than was
Z/E-nepetalactone (Table 1).
In experiments 4-6, two essential oil mixtures including 3 or 4 strongly repellent oils: 3EO-mix (clove, geranium, and lemongrass at 1:1:1) and 4EO-mix (clove, geranium, lemongrass, and rosemary at 1:1:1:1), respectively, alone were not attractive to either yellowjackets or paper wasps (Tables 4-6). Interestingly, traps baited with either EO-mix alone in experiment 4 had significantly less catches of yellowjackets or paper wasps than did the water blank control traps, indicating a repellency effect by these two EO-mixes on the water as a weak attractant for the wasps (Table 4); whereas in experiments 5 and 6, they were not different from the non-water related blank controls (Tables 5 & 6). 3EO-mix or 4EO-mix almost totally blocked the attraction of both yellowjackets and paper wasps to AA/2 MB or to the natural food attractant, bacon (Table 4 and Table 6); and strongly interrupted the attraction of yellowjackets to heptyl butyrate (Table 5). In experiment 5, paper wasps were not attracted to heptyl butyrate; therefore, no repellency effect of the EO-mix could be shown.
In experiment 7, the attractant (heptyl butyrate: HB) alone attracted a considerable amount of yellowjackets (mainly Vespula pensylvanica) from the surroundings during the minutes of observation, on an average of 5 landing and 12 approaching, respectively (
GC-EAD/MS Analyses of Behaviorally Active Essential Oils
In order to identify the potential chemical compositions from the strong behaviorally repellent essential oils that might be responsible for wasp repellency, a series of GC-EAD/MS analyses were carried out on eleven selected essential oil headspace samples against worker antennae of several yellowjacket and paper wasp species, Vespula pensylvanica, Dolichovespula maculata, Polistes dominulus, and P. aurifer. As shown in
In short, over 20 EAD-active compounds were identified from 11 selected behaviorally strong active repellent essential oils by four species of vespid wasp workers (see Table 12 for summary). Interestingly, no difference in EAD responses among yellowjacket and paper wasp species was detected.
Field Bioassays of the EAD-Active Synthetic Compounds
Twenty-two synthetic EAD-active compounds (identified from the repellent essential oils) were tested in four field-trapping experiments (experiments 8-11) against a powerful sugar-related attractant, AA/2 MB. In experiment 8, traps baited with the attractant (AA/2 MB) plus P/I-menthone caught significantly less (four times less) yellowjackets than did the attractant alone, while the other five compounds, 1,8-cineole, 6-methyl-5-hepten-2-one, linalool, camphor, and geranyl formate, were not significantly repellent at the doses tested (Table 7). P/I-menthone also showed >50% trap catch reduction to the paper wasps, but it was not statistically different from the attractant alone due to the overall low trap catches (low population density) (Table 7). In experiment 9, E/Z-citral and eugenol significantly reduced trap catches of yellowjackets by more than 70% and 95%, respectively; and they decreased trap catches of paper wasps by 88% and 58%, respectively. Four other tested compounds, β-citronellol, 4-terpineol, α-terpineol, and (−)-verbenone were inactive at doses tested (Table 8). In experiment 10, eight of the nine tested candidate compounds, 3-octanol, citronellal, α/β-thujones, methyl benzoate, benzyl acetate, d-carvone, pulegone, and methyl salicylate showed significant repellency (57-83%) effect on both yellowjackets and paper wasps, whereas geraniol was not different from the attractant alone at the dose tested (Table 9). In experiment 11, the only tested candidate compound, 4-methylanisole, did not show significant repellency to either yellowjackets or paper wasps at 90 mg/day release (Table 10). Overall, 50% of the synthetic EAD-active compounds tested showed a significant repellency on either yellowjackets or paper wasps or both (see Table 13 for summary).
This patent application discloses various essential oils and their chemical compositions are repellent candidates (or attraction-inhibitors) for pestiferous social wasps, namely yellowjackets, paper wasps, and hornets. Seventeen of the twenty-one essential oils tested showed significant repellency on either yellowjackets [Vespula pensylvanica (ca. 90%), plus V. vulgaris, V. germanica, and Dolichovespula maculata] or paper wasps (mainly Polistes dominulus, plus a few of P. aurifer) or both to the attractant AA/2 MB. Of these, clove oil (Myrtaceae), lemongrass oil (Poaceae), ylang ylang oil (Annonaceae), spearmint oil (Lamiaceae), wintergreen oil (Ericaceae), sage oil (Lamiaceae), rosemary oil (Lamiaceae), geranium oil (Geraniaceae), and lavender oil (Lamiaceae) at 30-45 mg/day releases totally blocked the attraction of these vespid wasps to their AA/2 MB attractants (Table 11). About 50% of the significantly active or strongly active repellent essential oils in this study were derived from the family Lamiaceae.
Two essential oil mixtures [3EO-mix (clove, geranium, and lemongrass) and 4EO-mix (clove, geranium, lemongrass, and rosemary)] in tests showed remarkably strong repellency; in fact, they totally blocked the attraction of both yellowjackets and paper wasps to AA/2 MB or to a natural food attractant, bacon (Table 4 and Table 6); and strongly interrupted the attraction of yellowjackets to a powerful attractant, heptyl butyrate (Table 5). The total blocking effect of this 3EO-mix was also shown in a field observation experiment where it was deployed at 50 cm (away from) above the attractant source (
GC-EAD analysis clearly showed that the wasp antennae do have olfactory receptor neurons for detecting various essential oils and some of their volatile compounds (
While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.
This application claims the benefit of U.S. Provisional Application No. 61/372,338, filed Aug. 10, 2010, and also claims the benefit of U.S. Provisional Application No. 61/477,521, filed Apr. 20, 2011, each of which is fully incorporated herein expressly by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61477521 | Apr 2011 | US | |
| 61372338 | Aug 2010 | US |
