Increased Trap Catches Research Articles

Multimodal interactions in Stomoxys navigation reveal synergy between olfaction and vision

Stomoxys flies exhibit an attraction toward objects that offer no rewards, such as traps and targets devoid of blood or nectar incentives. This behavior provides an opportunity to develop effective tools for vector control and monitoring. However, for these systems to be sustainable and eco-friendly, the visual cues used must be specific to target vector(s). In this study, we modified the existing blue Vavoua trap, which was originally designed to attract biting flies, to create a deceptive host attraction system specifically biased toward attracting Stomoxys. Our research revealed that Stomoxys flies are attracted to various colors, with red proving to be the most attractive and selective color for Stomoxys compared to the other colors tested. Interestingly, our investigation of the cattle–Stomoxys interaction demonstrated that Stomoxys flies do not prefer a specific livestock fur color phenotype, despite variation in the spectrum. To create a realistic sensory impression of the trap in the Stomoxys nervous system, we incorporated olfactory cues from livestock host odors that significantly increased trap catches. The optimized novel polymer bead dispenser is capable of effectively releasing the attractive odor carvone + p-cresol, with strong plume strands and longevity. Overall, red trap baited with polymer bead dispenser is environmentally preferred.

Sex Attractant Blend for Dioryctria mongolicella (Lepidoptera: Pyralidae) in the Northeast of China

Abstract The Mongolian pine borer, Dioryctria mongolicella Wang & Sung (Lepidoptera: Pyralidae), is a major pest in Mongolian pine (Pinus sylvetris L. var. mongolica Litvinov) plantations in the northeast of China. A blend of 11-hexadecenal and 11-hexadecenyl acetate in a ratio of 2:1 was detected from extracts of its female sex pheromone glands by gas chromatography–mass spectrometry. Our field trapping experiments confirmed that the D. mongolicella pheromone consists of a blend of (E)-11-hexadecenal (E11-16:Ald) and (Z)-11hexadecenyl acetate (Z11-16:Ac). The addition of (Z,E)-9,11-tetradecadienyl acetate (Z9E11-14:Ac) and (Z,Z,Z)-3,6,9-tricosatriene (ZZZ3,6,9-23:H) increased catches of male D. mongolicella in sticky traps baited with E11-16:Ald and Z11-16:Ac. However, the addition of (3Z,6Z,9Z,12Z,15Z)-pentacosapentaene or (Z,Z,Z,Z,Z)-3,6,9,12,15-tricosapentaene to lures loaded with E11-16:Ald, Z11-16:Ac, and Z9E11-14:Ac did not significantly increase trap catches of D. mongolicella at two locations in Heilongjiang province, China. The synthetic blend of 400 µg E11-16:Ald, 200 µg Z11-16:Ac, 200 µg Z9E11-14:Ac, and 500 µg ZZZ3,6,9-23:H will help in developing efficient strategies for monitoring and control of D. mongolicella populations in Mongolian pine plantations.

Field Confirmation of (Z)-9-Heptacosene and (3Z,6Z,9Z)-Tricosatriene as Key Sex Pheromone Components of Korean Conogethes punctiferalis Guenée (Lepidoptera: Crambidae).

Recently, insufficient attractiveness of Conogethes punctiferalis Guenée adult males to sex pheromone, -(E)-10-hexadecenal and (Z)-10-hexadecenal, has been reported. To identify the other essential components of sex pheromone, male and female body extracts were analyzed. Two hydrocarbon components, (Z)-9-heptacosene (Z9-27:HC) and (3Z,6Z,9Z)-tricosatriene (Z3,Z6,Z9-23:HC), were identified from only female body extract. There was a significant difference in the electroantennogram (EAG) response of male antennae to Z3,Z6,Z9-23:HC and Z9-27:HC at all test concentrations compared to the response to the hexane control. In field attraction testing, the addition of Z9-27:HC and Z3,Z6,Z9-23:HC to binary aldehyde pheromones significantly increased trap catches of C. punctiferalis male adults. Based on the female and male body extract analysis and field attraction test, Z9-27:HC and Z3,Z6,Z9-23:HC were determined to be other essential sex pheromone components of the Korean C. punctiferalis population. No significant difference was observed in the number of male captures between the bucket trap and delta trap. Pheromone traps with a color close to yellow shade attracted more male adults than traps with a color close to blue shade.

Cinnamyl alcohol: An attractant of the flower thrips Frankliniella intonsa

Catches of Frankliniella intonsa females (A) and males (B) in traps baited with five floral compounds (10 mg each) in red pepper fields • The flower thrips Frankliniella intonsa are attracted to highbush blueberry flowers. • Cinnamyl alcohol was the major component of floral volatiles of highbush blueberry. • Cinnamyl alcohol significantly attracted adult F. intonsa in the field. • The minor floral compounds had no additive activity with cinnamyl alcohol alone. Flower-inhabiting thrips find hosts using olfactory and visual cues. In this study, we report the identification of a plant-produced attractant of the flower thrips Frankliniella intonsa (Trybom), an important agricultural pest worldwide. GC–MS analysis of solid-phase microextraction samples from blueberry flowers, Vaccinium corymbosum L., that mediate the attraction of adult F. intonsa revealed that the major component was cinnamyl alcohol, followed by cinnamyl acetate, cinnamaldehyde, germacrene D, β -bourbonene, β -caryophyllene, and benzyl benzoate. The biological activity of the floral compounds was investigated using commercial cinnamaldehyde, cinnamyl alcohol, β -caryophyllene, cinnamyl acetate, and benzyl benzoate in hot pepper ( Capsicum annuum L.) fields. Significantly more F. intonsa males and females were caught in red delta traps with cinnamyl alcohol than in all other traps. Cinnamaldehyde and cinnamyl acetate attracted adult F. intonsa but were not as attractive as cinnamyl alcohol. β -Caryophyllene and benzyl benzoate were not attractive. Furthermore, the addition of four minor components to cinnamyl alcohol did not result in increased trap catches relative to cinnamyl alcohol alone, indicating that cinnamyl alcohol is responsible for attracting adult F. intonsa toward blueberry flowers. Therefore, this phenylpropanoid could be used as an effective lure for monitoring and controlling F. intonsa .

Effects of Ethanol and α-Pinene in a Generic Trap Lure Blend for Pine Bark and Wood-Boring Beetles in Southeastern United States

Abstract Managers of detection programs for bark and wood-boring beetles require cost-effective trap lure combinations that maximize species detections. A trapping study was conducted in 2012 to determine the effects of ethanol and α-pinene lures on beetle catches in traps baited with ipsenol and ipsdienol lures in a stand of Pinus taeda L. in north-central Georgia. Traps with all four compounds worked well for 20 of 25 species of bark and wood-boring beetles, and associated predators. Catches of Acanthocinus obsoletus (LeConte) and Monochamus titillator (F.) (Cerambycidae), Hylastes porculus Erichson, Hylastes salebrosus Eichhoff, Hylobius pales (Herbst), Orthotomicus caelatus (Eichhoff) (Curculionidae), Thanasimus dubius (F.) (Cleridae), and Temnoscheila virescens (F.) (Trogossitidae) in baited traps increased with the addition of ethanol and α-pinene with maximum catches in traps baited with all four compounds. Catches of Ips avulsus (Eichhoff) (Curculionidae) decreased with the addition of both compounds; the lowest numbers of I. avulsus and Ips grandicollis (Eichhoff) were caught in traps baited with all four compounds. α-Pinene increased catches of Buprestis lineata F. (Buprestidae), Ips calligraphus (Germar), Pachylobius picivorus (Germar) (Curculionidae), Corticeus spp. (Tenebrionidae), Lasconotus spp., and Pycnomerus sulcicollis LeConte (Zopheridae); ethanol had no effect on these species. Ethanol increased trap catches of Curius dentatus Newman (Cerambycidae), Dryoxylon onoharaense (Murayama) (Curculionidae) and Platysoma spp. (Histeridae); α-pinene reduced catches. The data suggest that ethanol and α-pinene should be retained with ipsenol and ipsdienol as a generic trap lure blend for pine bark and wood-boring beetles in southeastern United States.

Behavioral Responses of Sea Lamprey to Varying Application Rates of a Synthesized Pheromone in Diverse Trapping Scenarios.

Use of the first fish pheromone biopesticide, 3-keto petromyzonol sulfate (3kPZS) in sea lamprey (Petromyzon marinus) control requires an understanding of both how the amount 3kPZS applied to a trap relates to catch, and how that relationship varies among stream types. By conducting 3kPZS dose-response experiments over two years and across six varied trapping contexts, we conclude (1) that 3kPZS application is best standardized by how much is emitted from the trap instead of the fully mixed concentration achieved downstream, and (2) that 3kPZS is more effective in wide streams (>30m). In wide streams, emission of 3kPZS at 50mghr.-1 from the trap increased capture rate by 10-15% as sea lamprey were 25-50% more likely to enter the trap after encounter. However, in narrow streams (< 15m), 50mghr.-1 3kPZS generally reduced probabilities of upstream movement, trap encounter, and entrance. While 3kPZS significantly influenced upstream movement, encounter, and capture probabilities, these behaviors were also highly influenced by water temperature, stream width, sea lamprey length, and sex. This study highlights that a pheromone component in a stream environment does not ubiquitously increase trap catch in all contexts, but that where, how, and when the pheromone is applied has major impacts on whether it benefits or hinders trapping efforts.

Aedes vector-host olfactory interactions in sylvatic and domestic dengue transmission environments.

Interactions between Aedes (Stegomyia) species and non-human primate (NHP) and human hosts govern the transmission of the pathogens, dengue, zika, yellow fever and chikungunya viruses. Little is known about Aedes mosquito olfactory interactions with these hosts in the domestic and sylvatic cycles where these viruses circulate. Here, we explore how the different host-derived skin odours influence Aedes mosquito responses in these two environments. In field assays, we show that the cyclic ketone cyclohexanone is a signature cue for Aedes mosquitoes to detect the NHP baboon, sykes and vervet, whereas for humans, it is the unsaturated aliphatic keto-analogue 6-methyl-5-hepten-2-one (sulcatone). We find that in the sylvatic environment, CO2-baited traps combined with either cyclohexanone or sulcatone increased trap catches of Aedes mosquitoes compared to traps either baited with CO2 alone or CO2 combined with NHP- or human-derived crude skin odours. In the domestic environment, each of these odourants and crude human skin odours increased Aedes aegypti catches in CO2-baited traps. These results expand our knowledge on the role of host odours in the ecologies of Aedes mosquitoes, and the likelihood of associated spread of pathogens between primates and humans. Both cyclohexanone and sulcatone have potential practical applications as lures for monitoring Aedes disease vectors.

Comparison of Different Trap Designs for Capture of Noctuid Moths (Lepidoptera: Noctuidae) With Pheromone and Floral Odor Attractants.

Six trap designs were assessed for capturing noctuid moths in field trials in the United Kingdom and Argentina. The traps were baited with either a sex pheromone for Autographa gamma in the UK trials and Helicoverpa gelotopoeon (Dyar) (Lepidoptera: Noctuidae) in Argentina, or a floral odor blend. In the UK trials the Universal Trap and a funnel sleeve trap were compared; in Argentina the funnel sleeve trap, a homemade bucket trap, and (L.) (Lepidoptera: Noctuidae) three sticky traps: LepTrap, wing trap, and delta trap were compared. Comparisons were made between the traps and attractants and captures of noctuid moths and nontarget insects. Traps baited with the floral attractant caught a lower number but a wider range of noctuid species including Helicoverpa, Spodoptera, Rachiplusia, Dargida, Mythimna, Chrysodeixis, Agrotis, and Autographa spp., and nontarget insects. In the UK trials, the funnel sleeve trap caught significantly more A. gamma than the Universal Trap. The addition of an insecticide to the Universal Trap marginally increased trap catches. In the Argentinian trials, the homemade bucket and the sleeve traps outperformed all sticky traps in most situations regardless of crop environment and attractant type. The homemade bucket and the funnel sleeve traps are also considerably cheaper than the other trap designs. Of the sticky traps the LepTrap caught more noctuids than the wing and delta traps. The results suggest that the bucket trap and the sleeve trap have a much greater maximum capacity and possibly a greater retention efficiency for noctuid moths compared to the sticky traps.

Optimizing pheromone-based lures for the invasive red-necked longhorn beetle, Aromia bungii

Aromia bungii is a serious pest of stone fruit trees including cherries, plums, peaches and apricots. It is native to eastern Asia but has recently been introduced into and has established in Japan, Germany and Italy and has been intercepted in cargo entering the USA and Great Britain. We synthesized the naturally produced enantiomer of the major pheromone component, (E)-2-cis-6,7-epoxynonenal, and in field tests, comparing its attractiveness to that of the racemate. We also tested different ratios of a minor pheromone component, (2E,6Z)-nona-2,6-dienal, on attraction to the major component. Lastly, we conducted a dose–response assay to determine the optimal loading rates. Addition of the minor component at a ratio of 0.31 mg minor to 25 mg major component is more than double the trap captures of males but not females. Using this ratio, we found no difference in trap captures with 10 mg, 32 mg or 100 mg of the major component, but the 10 mg load attracted significantly more females than the 3.2 mg load, and only the 32 mg load attracted significantly more males than the 3.2 mg load. The natural enantiomer was significantly more attractive to females than the racemate. However, the multi-step, low-yielding synthesis likely will prohibit the insect-produced enantiomer from being used for operational trapping. The addition of the minor component to the racemate significantly increased trap catches, and the dose–response assay did not indicate significant differences in loads above 10 mg of the racemic major component when formulated with ~ 1.2% of the minor component.

Alcohol Contributes to Attraction of Heliothis (= Chloridea) virescens Males to Females.

Female-emitted volatile sex pheromones in most moths are composed of biosynthetically related blends of fatty acid derivatives, such as aldehydes, acetate esters and alcohols. In many moths, as in the noctuid Heliothis (Chloridea) virescens, the pheromone gland contains alcohols (e.g., (Z)-11-hexadecen-1-ol, hereafter Z11-16:OH) that may serve dual functions as pheromone components as well as precursors of other pheromone components. The relative importance of Z11-16:OH to male attraction in H. virescens has been controversial. It occurs in the pheromone gland in relatively large amounts, but several studies could neither detect Z11-16:OH in gland emissions nor attribute any conspecific behavioral function to it in flight- tunnel assays. Trapping assays in the field, however, have more consistently documented that the addition of Z11-16:OH increased trap catch. Using a short section of thick film megabore column, in combination with derivatization and GC-CI-SIM-MS, we determined that Z11-16:OH is emitted from the sex pheromone gland during calling. Field trapping studies demonstrated that trap catch increased when Z11-16:OH was added to a 2-component minimal blend and to a 6-component blend. Behavioral observations in the field confirmed that more males responded to a pheromone blend that contained a low blend ratio of Z11-16:OH, but ≥5% Z11-16:OH depressed both male behavior and trap catch. We conclude that Z11-16:OH should be considered a component of the sex pheromone of H. virescens females.

Reduced translucency and the addition of black patterns increase the catch of the greenhouse whitefly, Trialeurodes vaporariorum, on yellow sticky traps.

The greenhouse whitefly Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) is a pest of a wide range of vegetable and ornamental crops in greenhouses around the world. Yellow sticky traps are highly attractive to flying adults and so are frequently used to monitor the pest. Our aim was to test whether changes in trap translucency or the addition of printed black patterns could increase the catch on yellow sticky traps in greenhouses. Field trials were carried out in commercial crops of strawberry and tomato under glass over three years. Reduced trap translucency increased trap catches by a factor of 1.5 to 7.0 and the catch increased significantly for both females and males. Spectrometer measurements showed that the increased catch was consistent with an increased landing stimulus from a colour opponency mechanism i.e. the ratio of energy from 500–640 nm to the energy from 300–500 nm. Printed black patterns increased trap catches on specific types of trap, by a factor of 1.4 to 2.3, and the catch increased significantly for both females and males. The patterns increased trap catch on moderately translucent traps, but decreased trap catch on less translucent traps. The evidence points to a contrast/edge effect of pattern, but laboratory experiments are needed to clarify this. Exploitation of these translucency and pattern effects could improve the efficacy of yellow traps for monitoring and mass trapping in crops.

Variation in host preferences of malaria mosquitoes is mediated by skin bacterial volatiles.

The host preferences of the anthropophilic mosquito species in the Anopheles gambiae complex (Diptera: Culicidae) are mediated by skin bacterial volatiles. However, it is not known whether these mosquitoes respond differentially to skin bacterial volatiles from non-human host species. In this study, the responses of two malaria mosquito species in the An. gambiae complex, Anopheles gambiae s.s. (hereafter, An. gambiae) and Anopheles arabiensis, with different host preferences, to volatiles released from skin bacteria were tested. Skin bacteria collected from human, cow and chicken skin significantly increased trap catches; traps containing bacteria collected from human skin caught the highest proportions of An. gambiae and An. arabiensis. Traps with bacteria of human origin caught a significantly higher proportion of An. gambiae than of An. arabiensis, whereas bacterial volatiles from the chicken attracted significantly higher numbers of An. arabiensis than of An. gambiae. Additionally, An. gambiae showed a specialized response to volatiles from four specific bacteria, whereas An. arabiensis responded equally to all species of bacteria tested. Skin bacterial volatiles may therefore play important roles in guiding mosquitoes with different host preferences. The identification of these bacterial volatiles can contribute to the development of an odour blend that attracts mosquitoes with different host preferences.

Olfactory Cues, Visual Cues, and Semiochemical Diversity Interact During Host Location by Invasive Forest Beetles

Plant-feeding insects use visual and olfactory cues (shape, color, plant volatiles) for host location, but the relative importance of different cues and interactions with non-host-plant volatiles in ecosystems of varying plant biodiversity is unclear for most species. We studied invasive bark beetles and wood borers associated with pine trees to characterize interactions among color, host and non-host volatiles, by employing traps that mimic tree trunks. Cross-vane flight intercept traps (black, green, red, white, yellow, clear) and black funnel traps were used with and without attractants (α-pinene + ethanol), repellents (non-host green leaf volatiles, 'GLV'), and attractant/repellent combinations in four pine forests in New Zealand. We trapped 274,594 Hylurgus ligniperda, 7842 Hylastes ater, and 16,301 Arhopalus ferus. Trap color, attractant, and color × attractant effects were highly significant. Overall, black and red traps had the highest catches, irrespective of the presence of attractants. Alpha-pinene plus ethanol increased trap catch of H. ligniperda 200-fold but only 6-fold for H. ater and 2-fold for A. ferus. Green leaf volatiles had a substantial repellent effect on trap catch of H. ligniperda but less on H. ater and A. ferus. Attack by H. ligniperda was halved when logs were treated with GLV, and a similar effect was observed when logs were placed among broadleaved understory shrubs emitting GLV. Overall, H. ligniperda was most strongly affected by the olfactory cues used, whereas H. ater and A. ferus were more strongly affected by visual cues. Collectively, the results support the semiochemical diversity hypothesis, indicating that non-host plant volatiles from diverse plant communities or artificial dispensers can contribute to resistance against herbivores by partly disrupting host location.

Capture of Nontarget Flies (Diptera: Lauxaniidae, Chloropidae, and Anthomyiidae) on Traps Baited with Volatile Chemicals in Field-Crop Habitats

Volatile chemicals increased trap catch of flies from the families Lauxaniidae [Homoneura bispina(Loew) andCamptoprosopella borealisShewell], Chloropidae (Olcellasp.), and Anthomyiidae (Deliaspp.) in field crops. With lauxaniids, baiting with 2-phenylethanol on cotton-roll dispensers increased catch ofH.bispinain two corn plot tests, and methyl salicylate increased trap catch in one test. Traps baited with methyl salicylate increased the catch ofC.borealis. When using plastic-sachet dispensers, traps baited with methyl salicylate caught moreH.bispinathan ones baited with 2-phenylethanol, whereas traps baited with 2-phenylethanol caught moreC.borealisthan those with methyl salicylate. For chloropids, traps baited with 2-isopropyl-3-methoxypyrazine greatly increased catch ofOlcellaflies in corn and soybean. With anthomyiids, catch of maleDeliaflies in wheat increased with 2-phenylethanol on cotton rolls and with either 2-phenylethanol or methyl salicylate using plastic dispensers. In soybean, 2-phenylethanol formulated on cotton rolls or in plastic dispensers increased catch of maleDeliaflies, but methyl salicylate did not affect trap catch. Trap catch of femaleDeliaflies did not vary among chemicals. In another test in soybean, trap catch of both male and femaleDeliaflies was greater with 2-phenylethanol than with other volatile chemicals.

Volatile Semiochemicals Increase Trap Catch of Green Lacewings (Neuroptera: Chrysopidae) and Flower Flies (Diptera: Syrphidae) in Corn and Soybean Plots.

This study reports on the attractiveness of volatile chemicals to green lacewings (Neuroptera: Chrysopidae) and flower flies (Diptera: Syrphidae) as measured by catch on yellow sticky traps within corn [Zea mays L. (Cyperales: Poaceae)] and soybean [Glycine max (L.) Merr. (Fabales: Fabaceae)] plots. Green lacewings were attracted to eugenol-baited traps in two tests in soybean plots. Follow-up testing in corn showed that catch of green lacewings was enhanced when traps were baited with eugenol, its structural analog isoeugenol, or 2-phenylethanol; trap catch of green lacewings was greater with these compounds than with structural analog, 4-alllylanisole. In a follow-up test in soybean, more green lacewings were caught on traps baited with isoeugenol than with 4-allylanisole. Catch did not differ among traps baited with eugenol, isoeugenol, or 2-phenylethanol or among those baited with eugenol, 2-phenylethanol, or the ethanol control. In a 6-wk experiment in soybean, green lacewings were attracted to eugenol-baited traps in 5 of 6 wks but to traps baited with structural analog methyl eugenol in only 1 wk. Flower flies were attracted to 2-phenylethanol in initial tests in corn and soybean plots. Subsequent testing in soybeans with 2-phenylethanol and structural analogs confirmed attraction to 2-phenylethanol and also showed attractancy of 2-phenylacetaldehyde but not benzylamine. A 6-wk test in soybean found that flower flies were also attracted to traps baited with either eugenol or methyl eugenol. This is the first report of green lacewing attraction to eugenol and isoeugenol and first report of flower fly attraction to eugenol. Structure-activity relationships among attractants and practical aspects of their use are discussed.

Identification and field verification of sex pheromone from the mirid bug, Adelphocoris suturalis

Numerous species of mirid bugs (Hemiptera: Miridae) are phytophagous insect pests that damage economically important field and horticultural crops. In recent years, Adelphocoris suturalis has become a significant pest in transgenic Bacillus thuringiensis (Bt) cotton fields. We previously reported that virgin A.suturalis females attracted males in the field. In this study, we found that A. suturalis males are not attracted in Y-tube olfactometer bioassays to odors from either live nymphs or sexually mature virgin females whose ostioles of the metathoracic scent gland (MTG) are occluded with paraffin wax. However, males are significantly attracted to odors from adult virgin females when female abdomina are occluded with paraffin, indicating that female A. suturalis release sex pheromones only from the MTG. Volatile extracts from both sexes were collected and analyzed by gas chromatography–electroantennogram detection and gas chromatography–mass spectrometry. We identified (E)-4-oxo-2-hexenal (E4O2H), hexyl hexanoate (HH) and hexyl butyrate (HB) as major components and found that they elicited the largest EAD responses from antennae of males. Both E4O2H and HH were present in aeration extracts from females, while E4O2H was found in males. Capture of only males in field tests using synthetic compounds confirmed the activity of the identified sex pheromone candidates. In the field tests, a 10:1 ratio of the E4O2H and HH binary blend exhibited the highest efficiency in attracting male A. suturalis. Addition of HB to the binary pheromone blend to make a ternary blend did not increase trap catches. These results demonstrate that E4O2H and HH constitute the A. suturalis sex pheromone components.

Effectiveness of a Sugar-Yeast Monitor and a Chemical Lure for Detecting Bed Bugs

Effective bed bug (Cimex lectularius L.) monitors have been actively sought in the past few years to help detect bed bugs and measure the effectiveness of treatments. Most of the available active monitors are either expensive or ineffective. We designed a simple and affordable active bed bug monitor that uses sugar-yeast fermentation and an experimental chemical lure to detect bed bugs. The sugar-yeast mixture released carbon dioxide at a similar rate (average 405.1 ml/min) as dry ice (average 397.0 ml/min) during the first 8 h after activation. In naturally infested apartments, the sugar-yeast monitor containing an experimental chemical lure (nonanal, L-lactic acid, 1-octen-3-ol, and spearmint oil) was equally effective as the dry ice monitor containing the same lure in trapping bed bugs. Placing one sugar-yeast monitor per apartment for 1-d was equally effective as 11-d placement of 6-18 Climbup insect interceptors (a commonly used bed bug monitor) under furniture legs for trapping bed bugs. When carbon dioxide was present, pair-wise comparisons showed the experimental lure increased trap catch by 7.2 times. This sugar-yeast monitor with a chemical lure is an affordable and effective tool for monitoring bed bugs. This monitor is especially useful for monitoring bed bugs where a human host is not present.

A new attractant for monitoring western flower thrips, Frankliniella occidentalis in protected crops.

Monitoring of pest populations is an essential component of integrated pest management. An early warning system helps growers decide when best to take control measures, or when to alter them, should a control method prove inadequate. Studies have shown that adding chemical attractants to sticky cards can increase trap catch of western flower thrips, Frankliniella occidentalis, a global pest of agriculture and horticulture, giving more accurate accounts of population size and dynamics, thus leading to more efficient monitoring. We identify a novel semiochemical to the species, (S)-(−)-verbenone, showing that addition of this compound to sticky traps significantly increased F. occidentalis catch in two geographically distinct populations, infesting two unrelated crops of global economic importance. We validate through field trials that (S)-(−)-verbenone is highly attractive to F.occidentalis and can be used with blue sticky traps to enhance trap catch, leading to better estimations of pest population densities. The compound may be used in other control methods against F.occidentalis such as lure and kill, mass trapping and push-pull.Electronic supplementary materialThe online version of this article (doi:10.1186/s40064-015-0864-3) contains supplementary material, which is available to authorized users.

Combining 1,4-dimethoxybenzene, the major flower volatile of wild strawberry Fragaria vesca, with the aggregation pheromone of the strawberry blossom weevil Anthonomus rubi improves attraction

The aggregation pheromone of strawberry blossom weevil [Anthonomus rubi Herbst (Col.: Curculionidae)], a 1:4:1 blend of Grandlure I, II and racemic lavadulol, has been available for pest monitoring for several years but shows low attractancy. Attempts to control A. rubi using the pheromone alone were also unsuccessful. This paper reports the finding that addition of the major flower volatile from wild strawberry flowers [Fragaria vesca L. (Rosaceae)], 1,4-dimethoxybenzene (comprising 98% of the volatiles emitted from wild strawberry flowers), to the aggregation pheromone increased trap catches by over two fold compared to the pheromone alone. There was no significant difference between the response of overwintered or summer emerged adults. Field trials in 2007–2008 in central and southern Norway, Denmark and southern England used green funnel traps with white cross vanes for the evaluations. (-)-Germacrene D, previously shown to be emitted by plants in increased amounts in the presence of pheromone producing weevils, did not improve trap catches. Thus, the combined use of the aggregation pheromone and 1,4-dimethoxybenzene is promising for improved monitoring and possibly control of this important pest of strawberry.

Evaluation of Color and Scent Attractants Used to Trap and Detect Asian Ctirus Psyllid (Hemiptera: Liviidae) in Urban Environments

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae) is a serious pest of citrus due to its ability to vector the putative causal agent of huanglongbing, ‘Candidatus Liberibacter asiaticus'. Populations of Asian citrus psyllid (ACP) can increase in density in urban areas and then move out into adjacent commercial citrus production. Current presence/ absence detection methods for ACP in urban areas rely on the use of yellow sticky traps without a scent lure. This method was selected because of its accepted use in commercial production, however, in urban areas it may not be the most efficient method for trapping ACP. Therefore, we investigated the relative trapping efficiency of 4 different colored traps (2 hues of yellow and 2 hues of green) and the addition of 2 scent lures to yellow sticky traps. The lures were based on the volatiles emitted either from flush growth of Eureka lemon or Mexican lime. The tests were conducted in residential areas in Los Angeles, California in 2011. All of the sites were dooryard sites and trapping was done with homeowner permission. There were no statistically significant differences in trap catch between the yellow and green traps, suggesting that any of the traps tested could be used for ACP detection in an urban environment. There was no correlation between flush density and trap catches. The host plant on which the colored traps were placed did not significantly influence trap catch, although numerically more ACP adults were captured on lemon and lime trees, regardless of trap color. When scent lures were added to yellow sticky traps, no statistically significant differences were found between traps with lures and those without lures, regardless of host plant. Trapping studies for ACP in the urban environment need to be continued using more sample sites to determine if the addition of scent lures based on plant volatiles will increase trap catches.