Acute toxicity of the bird repellent,methyl anthranilate,to fry of Salmo salar,Oncorhynus mykiss,Ictalurus punctatus and Lepomis macrochirus

Several laboratory and field studies have shown methyl anthranilate to be an effective, non-toxic and non-lethal bird repellent, with application potential for protecting crops, seeds, turf and fish stocks from bird damage. Furthermore, methyl anthranilate can be added to liquids for the purposes of protecting migratory birds, e.g. addition to waste water associated with mining and to standing water pools at airports. Mammalian toxicity data are favorable. Methyl anthranilate is used as a fragrance and food flavoring and is GRAS listed by the US Food and Drug Administration. Despite the favorable outlook for methyl anthranilate's use as a safe repellent, no data exist on its environmental fate and effects. We have tested the acute toxicity of methyl anthranilate in a static system against the fry of four species of fish. The LC₅₀ at 24 h for Atlantic salmon (Salmo salar L.) was 32.3 mg liter^?1, with the no observable effect limit at 6 mg liter^?1. The LC₅₀ at 24 h for rainbow trout (Oncorhynus mykiss Richardson) was 23.5 mg liter^?1, with the no observable effect limit at 5 mg liter^?1. The LC₅₀ at 24 h for channel catfish (Ictalurus punctatus Raf.) was estimated to be 20.1 mg liter^?1, with the no observable effect limit at 7 mg liter^?1. The LC₅₀ at 24 h for bluegill sunfish (Lepomis macrochirus Raf.) was estimated to be 19.8 mg liter^?1, with the no observable effect limit at 7 mg liter^?1..     

Designer repellents: combining olfactory, visual or taste cues with a secondary repellent to deter free-ranging house sparrows from feeding

BACKGROUND: Repellents may prevent bird pests from eating crops or protect non‐target birds from eating harmful substances. The feeding behaviour of free‐ranging house sparrows (Passer domesticus) presented with wheat treated with the secondary repellent anthraquinone (AQ), paired with visual and/or olfactory and taste cues, was recorded in a series of trials. The aim was to determine the suitability of repellent combinations for preventing birds from consuming pest baits. RESULTS: Anthraquinone significantly reduced wheat consumption. The addition of cinnamon oil did not reduce consumption further, but the addition of either a blue colour or d‐pulegone enhanced repellency. Green wheat was consumed more than blue wheat. In a multichoice test, the sparrows did not differentiate between low and high concentrations of AQ on blue‐dyed wheat. With treatments on separate tables, the higher concentration was more repellent. Additional olfactory/gustatory cues palatable to pest mammals did not make the AQ‐treated wheat more or less acceptable to sparrows. AQ‐treated blue wheat with/without cinnamon oil was more repellent than green wheat with cinnamon oil, a colour/odour combination typically used for pest baits in New Zealand. CONCLUSIONS: These data demonstrate the potential of combining the secondary repellent AQ with additional salient cues for modifying the feeding behaviour of sparrows. Copyright © 2011 Society of Chemical Industry     

Enhanced repellency of binary mixtures of Zanthoxylum piperitum pericarp steam distillate or Zanthoxylum armatum seed oil constituents and Calophyllum inophyllum nut oil and their aerosols to Stomoxys calcitrans

BACKGROUND: The repellency to stable fly, Stomoxys calcitrans (L.), of Zanthoxylum piperitum (L.) DC pericarp steam distillate (ZP‐SD), Zanthoxylum armatum DC seed oil (ZA‐SO) and their constituents alone or in combination with Calophyllum inophyllum L. nut oil (CI‐NO), as well as six aerosol formulations containing ZP‐SD or ZP‐SO and CI‐NO, was compared with that of a synthetic repellent, DEET, using an exposed human hand bioassay. RESULTS: At 0.20 mg cm^?2, ZP‐SD treatments resulted in 91 and 68% repellency following 30 and 60 min exposure respectively, while DEET gave 100 and 84% repellency. ZA‐SO was less effective than ZP‐SD. At 0.2 mg cm^?2, the most active constituents, cuminaldehyde, cuminyl alcohol, limonene and methyl cinnamate, gave 82, 74, 74 and 64% repellency at 30 min respectively, but DEET gave 100 and 87% repellency at 30 and 60 min. An increase in effectiveness and duration of repellency was produced by binary mixtures of ZP‐SD, ZA‐SO or bioactive constituents (each 0.01 mg cm^?2) and CI‐NO (0.99 mg cm^?2). The repellency of aerosols containing 2.5% ZP‐SD or 2.5% ZA‐SO and 2.5% CI‐NO was comparable with that of 5% DEET aerosol. CONCLUSION: Mixtures formulated from ZP‐SD, ZA‐SO or bioactive constituents and CI‐NO could be useful as potential repellents for the control of stable fly populations in light of global efforts to reduce the level of highly toxic synthetic repellents. Copyright © 2010 Society of Chemical Industry     

Ortho-aminoacetophenone,a non-lethal repellent: The effect of volatile cues vs. direct contact on avoidance behavior by rodents and birds

Taxonomic differences in responsiveness to chemosensory irritants are prevalent among avian and mammalian species and represent a major obstacle to the development of general vertebrate repellents. We evaluated the effect of ortho-aminoacetophenone (OAP), a potent avian repellent, on ingestive behavior of two rodent species, Prairie vole (Microtus ochrogaster), Deer Mouse (Peromyscus maniculatus Wagn.), and an avian species, European starling (Sturnus vulgarus L.) utilizing similar experimental conditions to facilitate interspecies comparisons. All three species avoided OAP-treated food. Apple consumption by voles was decreased from a baseline of theoretical zero% by OAP (0·01–10·0 ml liter⁻¹), P <0·000 01, while mice avoided all but the lowest concentration of OAP (0·01−10 ml liter⁻¹), P <0·000 01. A repellent should elicit avoidance behavior prior to the animal having physical contact with the commodity, ideally producing aversion via volatile cues rather than through direct contact. Therefore, we utilized two delivery methods for presentation of the test solutions to evaluate the repellency of OAP in the presence and absence of direct contact. Apple consumption by birds following exposure to OAP by either direct contact or volatile cues differed from a baseline of theoretical zero% consumption, P < 0·001. When birds had access to OAP through both direct and volatile exposures, reduction in apple consumption by European starlings was greater than observed following contact with the compounds volatile cues alone, P < 0·03. These findings argue against a major role for olfaction or nasotrigeminal chemoreception in avoidance of OAP-treated food. Instead, taste or oral trigeminal chemoreception appear to mediate responding.     

Evaluation of cinnamamide as an avian repellent: Determination of a dose—response curve

The dose-response curve was quantified for the avian repellency of cinnamamide, a derivative of the plant secondary compound cinnamic acid, using a three-day, ‘short-term no-choice’ test. This test was designed to resemble more closely the availability of alternative food in the birds' natural environment than in previous no-choice studies. Cinnamamide reduced food consumption by feral pigeons (Columba livia Gmelin) at concentrations as low as 6.17 μmole g^?1 food (0.09% w/w) and this reduction increased with concentration. An R₅₀ index, the concentration at which food consumption was reduced by 50% was interpolated from the dose-response curve as 18.4 (±0.38) μmole g^?1 food 10.26% w/w). This index can now be matched with those of related compounds in future structure-activity studies. The birds' response to cinnamamide changed over the three-day trial with respect to concentration. Repellency declined at concentrations < R₅₀ and increased at concentrations > R₅₀. This suggests that pigeons become habituated to cinnamamide at low concentrations but at high concentrations they may develop a conditioned aversion. This study provides quantitative confirmation of previous laboratory and field demonstrations of cinnamamide's effectiveness as a non-lethal chemical repellent suitable for reducing avian pest damage.     

Laboratory trials of fatty acids as repellents or antifeedants against houseflies,horn flies and stable flies (Diptera: Muscidae)

BACKGROUND: Straight‐chain, saturated fatty acids (particularly C8, C9 and C10) have some known behavioral effects on insects such as mosquitoes, and were tested in combination for potential repellency/antifeedant activity in bioassays against three significant muscoid flies of medical/veterinary importance: houseflies, horn flies and stable flies. RESULTS: Mixtures of C8, C9 and C10 (1:1:1; 15% total actives in formulation) were highly repellent to houseflies and horn flies at or below 1 mg formulation cm^?2. Repellency time varied from < 1 day for houseflies to usually at least 3 days for horn flies. Individual longer‐chain‐length fatty acids were tested, and C11 repelled houseflies for up to 5–8 days, while C12 lasted 2 days. Minimum statistically significant repellency levels of the C8, C9 and C10 mixture (3 h after application) against horn flies were 0.06–0.12 mg cm^?2. A liquid formulation of the 15% C8, C9 and C10 mixture in a silicone oil carrier (at 2.8 mg AI cm^?2) was highly repellent against hungry stable flies in a blood‐feeding membrane bioassay for at least 8 h. CONCLUSION: The low toxicity and reasonable activity and persistence of these carboxylic acids make them good candidates for development as protective materials against pest flies in livestock settings. Copyright © 2009 Society of Chemical Industry     

Evaluation of a pelleted bait containing methyl anthranilate as a bird repellent

No-till agriculture involves the use of granular pesticide formulations, chemically treated seeds, and pelleted baits. Some of these may accidentally kill birds. We have tested whether methyl anthranilate (MA), a known bird repellent, would eliminate consumption of a pelleted bait. In two laboratory experiments and an outdoor aviary trial, cowbirds (Molothrus ater Bodd.) were presented with pellets containing pesticide and MA, pellets containing pesticide but no MA, and carrier pellets without pesticide or MA. Consumption of any formulation was low, but the addition of MA significantly decreased bait loss in the laboratory, and prevented the disappearance of bait in the outdoor trial.     

Review of anthraquinone applications for pest management and agricultural crop protection

We have reviewed published anthraquinone applications for international pest management and agricultural crop protection from 1943 to 2016. Anthraquinone (AQ) is commonly found in dyes, pigments and many plants and organisms. Avian repellent research with AQ began in the 1940s. In the context of pest management, AQ is currently used as a chemical repellent, perch deterrent, insecticide and feeding deterrent in many wild birds, and in some mammals, insects and fishes. Criteria for evaluation of effective chemical repellents include efficacy, potential for wildlife hazards, phytotoxicity and environmental persistence. As a biopesticide, AQ often meets these criteria of efficacy for the non‐lethal management of agricultural depredation caused by wildlife. We summarize published applications of AQ for the protection of newly planted and maturing crops from pest birds. Conventional applications of AQ‐based repellents include preplant seed treatments [e.g. corn (Zea mays L.), rice (Oryza sativa L.), sunflower (Helianthus annuus L.), wheat (Triticum spp.), millet (Panicum spp.), sorghum (Sorghum bicolor L.), pelletized feed and forest tree species] and foliar applications for rice, sunflower, lettuce (Lactuca sativa L.), turf, sugar beets (Beta vulgaris L.), soybean (Glycine max L.), sweet corn and nursery, fruit and nut crops. In addition to agricultural repellent applications, AQ has also been used to treat toxicants for the protection of non‐target birds. Few studies have demonstrated AQ repellency in mammals, including wild boar (Sus scrofa, L.), thirteen‐lined ground squirrels (Ictidomys tridecemlineatus, Mitchill), black‐tailed prairie dogs (Cyomys ludovicainus, Ord.), common voles (Microtus arvalis, Pallas), house mice (Mus musculus, L.), Tristram's jirds (Meriones tristrami, Thomas) and black rats (Rattus rattus L.). Natural sources of AQ and its derivatives have also been identified as insecticides and insect repellents. As a natural or synthetic biopesticide, AQ is a promising candidate for many contexts of non‐lethal and insecticidal pest management. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.     

Toxicological and biochemical response to azinphos-methyl in Cydia pomonella L. (Lepidoptera: Tortricidae) among orchards from the Argentinian Patagonia

BACKGROUND: Azinphos‐methyl is the main insecticide used to control codling moth on apple and pears in Northern Patagonia. The aim of this study was to evaluate the toxicological and biochemical response of diapausing larvae of codling moth in orchards subjected to different insecticide selection pressure. RESULTS: Dose–mortality assays with azinphos‐methyl in diapausing larvae of Cydia pomonella L. showed significant differences between the LD₉₅ from a population collected in one untreated orchard (2.52 µg moth^?1) compared with that in a laboratory‐susceptible population (0.33 µg moth^?1). Toxicity to azinphos‐methyl in field populations of diapausing larvae collected during 2003–2005 was evaluated by topical application of a discriminating dose (2.5 µg moth^?1) that was obtained from larvae collected in the untreated orchard (field reference strain). Significantly lower mortality (37.71–84.21%) was observed in three out of eight field populations compared with that in the field reference strain. Most of the field populations showed higher esterase activity than that determined in both the laboratory susceptible and the field reference strains. Moreover, there was a high association between esterase activity and mortality (R² = 0.64) among the field populations. On the other hand, a poor correlation was observed between glutathione S‐transferase activity and mortality (R² = 0.33) among larvae collected from different orchards. CONCLUSIONS: All the field populations evaluated exhibited some degree of azinphos‐methyl tolerance in relation to the laboratory susceptible strain. Biochemical results demonstrated that esterases are at least one of the principal mechanisms involved in tolerance to this insecticide. Copyright © 2008 Society of Chemical Industry     

Structural requirements for repellency: norsesquiterpenes and sesquiterpenoid derivatives of nootkatone against the Formosan subterranean termite (Isoptera: Rhinotermitidae)

BACKGROUND: Research has shown that the family of grapefruit flavors called nootkatones have significant repellant and toxic effects to Formosan subterranean termites (Coptotermes formosanus Shiraki). RESULTS: Nineteen synthetic nootkatone derivatives, along with three commercially available nootkatone derivatives, were tested for repellent activity against C. formosanus by a choice assay in a petri dish with a two‐step triage procedure. Based on the repellency threshold value, the relationships between structure and activity are discussed. CONCLUSION: Four derivatives of nootkatone have very high repellency and toxicity to C. formosanus, 9 times the potency of the primary compound nootkatone. Four other compounds have between 2 and 3 times the repellency of nootkatones, and three compounds are equal in their repellency to nootkatone. Copyright © 2010 Society of Chemical Industry     

A test for repellency to non-biting flies and a comparison of repellents using Musca domestica L.

A system for testing the effect of a repellent against nonbiting flies attracted to man was developed for Musca domestica L. and Musca vetustissima Walk., and was used to compare the repellency of a range of chemicals against the former. Both arms of one person were simultaneously exposed to large numbers of the test insect in a cage, with repellent applied to a 45 cm² area on one arm, and the solvent to an identical area on the other arm. By varying the dose of repellent, a dose-to-repellency relationship was established and evaluated using probit analysis to determine 50% (RD₅₀) and 90% (RD₉₀) repellency. Both values were required to characterise a repellent. Greatest uniformity of results was obtained with even illumination of the cages from above and exclusion of side lighting. RD₅₀ and RD₉₀ values were not affected by prior exposure of the flies in a cage and did not change with time. Of the repellents tested, dipropyl isocinchomeronate was the most effective against M. domestica. The repellent effect of mixtures of the compounds was tested against M. domestica and was less than expected by summation of the components acting alone, suggesting that to minimise the total dose of chemical applied to skin, single compounds are preferable to mixtures.     

Rejection of dyed field rodent baits by Feral Pigeons and Chukar Partridges

Whole wheat grain bait, treated with sodium fluoroacetate, is used to control field rodents in Israel. However, this bait constitutes a potential primary non-target hazard to seed-eating birds. In the present study black-, red-, green- and yellow-dyed whole wheat and sorghum grains, as well as undyed ones, were offered to feral pigeons,Columba livia, and to chukar partridges,Alectoris chukar, in the laboratory during 4 days. Grains were offered either piled on trays, or scattered. Consumption levels varied significantly (P<0.05) among varieties. The pigeons preferred undyed grain; black and yellow grains were consumed the least. The partridges preferred the undyed and black grains to all the other colored grains. When no undyed alternative was offered, the pigeons preferred red and green, and the partridges — black wheat. The pigeons preferred wheat whole grain, and the partridges — sorghum whole grain. When the pigeons received sorghum, a disliked grain, no significant difference (P>0.05) was observed in the consumption of the differently dyed grains.     

Sensitivity of Botrytis cinerea to chitosan and acibenzolar‐S‐methyl

BACKGROUND: The antifungal properties of chitosan and acibenzolar‐S‐methyl were evaluated to assess their potential for protecting grapes against Botrytis cinerea Pers.: Fr. isolated from Vitis vinifera L. The objectives were to determine the effects of these compounds on the in vitro development of B. cinerea and to assess their effectiveness at controlling grey mould on grapes stored at different temperatures. RESULTS: Both agents significantly inhibited the radial growth of this fungus species. The EC₅₀ was 1.77 mg mL^?1 for chitosan and 3.44 mg mL^?1 for acibenzolar‐S‐methyl. In addition, single grapes treated with aqueous solutions of chitosan (1.0 and 2.5 mg mL^?1) and acibenzolar‐S‐methyl (1.0 and 3.0 mg mL^?1) were inoculated with B. cinerea and incubated at both 4 and 24 °C. After 4 days at 24 °C, all the concentrations of chitosan and acibenzolar‐S‐methyl significantly reduced B. cinerea growth. However, at 4 °C, significant differences were only observed between chitosan at 2.5 mg mL^?1 and acibenzolar‐S‐methyl at both 1.0 and 3.0 mg mL^?1 and the corresponding controls. After 3 days at 24 °C, the greatest reduction in lesion size was obtained in grapes pretreated with acibenzolar‐S‐methyl at 3.0 mg mL^?1. Only the highest doses of these products significantly reduced the lesion diameters when grapes were stored for 3 days at 4 °C. CONCLUSIONS: Chitosan and acibenzolar‐S‐methyl could directly inhibit the growth of Botrytis cinerea in vitro and confer resistance on grapes against grey mould. Pretreatment with these compounds could be an alternative to traditional fungicides in post‐harvest disease control in grapes. Copyright © 2010 Society of Chemical Industry     

Bioactivity against Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) of Cymbopogon citratus and Eucalyptus citriodora essential oils grown in Colombia

BACKGROUND: Essential oils isolated from Cymbopogon citratus (DC) Stapf. and Eucalyptus citriodora Hook grown in Colombia were analysed by gas chromatography–mass spectrometry (GC‐MS) and tested for repellent activity and contact toxicity against Tribolium castaneum (Herbst.) (Coleoptera: Tenebrionidae). RESULTS: The main components of C. citratus oil were geranial (34.4%), neral (28.4%) and geraniol (11.5%), whereas those of E. citriodora were citronellal (40%), isopulegol (14.6%) and citronellol (13%). The mean repellent doses after 4 h exposure were 0.021 and 0.084 mL L^?1 for C. citratus and E. citriodora oils respectively—values lower than that observed for the commercial product IR3535 (0.686 mL L^?1). CONCLUSION: These studies showed the composition and repellent activity of essential oils of C. citratus and E. citriodora, suggesting that these are potential candidates as insect repellents. Copyright © 2010 Society of Chemical Industry     

Palatability of bird repellents to Rattus norvegicus

The palatability to captive, mostly laboratory-bred, Norway rats (Rattus norvegicus) of cereal-based baits containing 0.02 g kg-1 brodifacoum, with and without bird-repellent additives, was compared in a no-choice experimental design. Methyl anthranilate (25 g kg-1), dimethyl anthranilate (25 g kg-1) and cinnamamide (2.5 g kg-1) reduced bait consumption by the rats, but all except one rat ate enough bait to receive a lethal dose. Cinnamamide (1 g kg-1), ortho-aminoacetophenone (0.1 g kg-1) and tannic acid (20 g kg-1) did not reduce bait consumption and all rats died after eating baits. The concentration of cinnamamide palatable to rats has only a low and short-lived repellency to birds, so it does not warrant further investigation. However, ortho-aminoacetophenone and tannic acid should now be field-tested for palatability to all three rat species in New Zealand and for repellency to native New Zealand birds.     

Insecticidal and repellent properties of nine volatile constituents of essential oils against the American cockroach,Periplaneta americana (L.)

The toxic and repellent properties of nine major constituents of essential oils, comprising benzene derivatives and terpenes, were evaluated against Periplaneta americana (L.). Contact and fumigant toxicities to adult females and repellency to nymphs were determined. The decreasing order of knockdown activity via contact was methyl-eugenol>isosafrole=eugenol>safrole. The killing effect via contact was in the order eugenol=methyl-eugenol=isosafrole>safrole. Fumigant toxicity was only observed for safrole and isosafrole, with safrole being the more potent. Isoeugenol and the tested terpenes had neither contact nor fumigant toxic effect. The decreasing order of repellency to nymphs was safrole>isosafrole>methyl-eugenol=α-pinene> eugenol>isoeugenol. The benzene derivatives were generally more toxic and repellent to P. americana than the terpenes. The distance of the side chain double bond from the aromatic ring and the substitution of a methoxy group to these compounds appeared to be important determinants of their toxicity and repellency. © 1998 Society of Chemical Industry     

Attraction and antennal response of the common wasp,Vespula vulgaris (L.), to selected synthetic chemicals in New Zealand beech forests

BACKGROUND: The common wasp, Vespula vulgaris (L.), and the German wasp, Vespula germanica (F.), are significant problems in New Zealand beech forests (Nothofagus spp.), adversely affecting native birds and invertebrate biodiversity. This work was undertaken to develop synthetic attractants for these species to enable more efficient monitoring and management. RESULTS: Seven known wasp attractants (acetic acid, butyl butyrate, isobutanol, heptyl butyrate, octyl butyrate and 2,4‐hexadienyl butyrate) were field tested, and only heptyl butyrate and octyl butyrate attracted significantly higher numbers of wasps than a non‐baited trap. Accordingly, a series of straight‐chain esters from methyl to decyl butyrate were prepared and field tested for attraction of social wasps. Peak biological activity occurred with hexyl butyrate, heptyl butyrate, octyl butyrate and nonyl butyrate. Polyethylene bags emitting approximately 18.4–22.6 mg day^?1 of heptyl butyrate were more attractive than polyethylene bags emitting approximately 14.7–16.8 mg day^?1 of heptyl butyrate in the field. Electroantennogram (EAG) studies indicated that queens and workers of V. vulgaris had olfactory receptor neurons responding to various aliphatic butyrates. CONCLUSION: These results are the first to be reported on the EAG response and the attraction of social wasps to synthetic chemicals in New Zealand beech forests and will enable monitoring of social wasp activity in beech forests. Copyright © 2009 Society of Chemical Industry     

The Problem of Protecting Crops Against Harmful Birds in Poland

From the point of view of Polish agriculture, the rook (Corpus frugilegus L.) causes the most damage. Jackdaws (C. monedula L.) usually forage together with rooks and are equally abundant as a breeding species in the southern and central regions of Poland. Fields under spring oats, barley, wheat, maize, peas and winter wheat are the main feeding grounds of rooks and jackdaws. Unlike the corvine birds, starlings (Sturnus vulgaris L.), in Poland, only cause damage to cherry orchards, although in certain areas they also attack strawberries and currants. The house sparrows (Passer domesticus L.) cause considerable damage to ripening crops of wheat, barley, and sunflowers. Domestic pigeons cause considerable damage to crops of peas, wheat and maize grown within a 50 km radius of a town.     

Control of Fusarium oxysporum f. sp. cucumerinum of cucumbers by soil solarization with impermeable plastics and/or reduced doses of methyl bromide*

Soil solarization is not broadly adopted as a soil deinfestation method mainly because of its long duration (4–6 weeks). We present evidence showing that the duration of solarization can be reduced to nearly half using impermeable plastics and/or low doses of methyl bromide, while still ensuring effective control of Fusarium oxysporum f. sp. cucumerinum. Chlamydospores of a pathogenic isolate of F. o. cucumerinum, formed in sterile soil, were inserted into nylon mesh envelopes and incorporated into the soil prior to treatment at 20‐ and 30‐cm soil depths. Soil treatments included untreated control, soil solarization with polyethylene or impermeable plastics (LMG), and soil solarization with polyethylene or impermeable plastics plus 20 g m^?2 methyl bromide. According to the effects on artificial inocula of F. o. cucumerinum checked at weekly intervals for 4 weeks, soil solarization with impermeable plastics was most effective in destroying pathogen populations even two weeks after soil covering.