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Whitebark pine, Pinus albicaulis Engelm., is a subalpine tree endemic to western North America. This species provides multiple ecosystem services and is suffering widespread mortality from mountain pine beetle, Dendroctonus ponderosae Hopkins. Verbenone is a pheromone produced as D. ponderosae feed, and high air concentrations of verbenone deter D. ponderosae from colonizing trees. Synthetic verbenone has been formulated into products used to prevent D. ponderosae from colonizing trees. We compared the ability of verbenone pouches and SPLAT Verb to protect individuals and small stands of P. albicaulis. With individual trees in Montana, all treated trees survived regardless of verbenone formulation and rate, whereas untreated trees suffered 70 and 90% mortality in 2015 and 2016. In plot experiments in California from 2015 to 2017, and Oregon from 2015 to 2018, verbenone was applied to trees spaced ~10 m apart, and survival of small (12.7–23 cm DBH = diameter at 1.37 m height), medium (23.1–33 cm DBH) and large (>33 cm DBH) trees was compared. In California, where >80% of untreated trees survived, pouches increased survival ~2 to 3% and SPLAT Verb increased survival ~4 to 7% regardless of tree size. In Oregon, verbenone pouches and SPLAT Verb performed similarly on medium and small trees, but large trees had greater survival when treated with SPLAT Verb (~93%) than pouches (~82%). Compared to verbenone pouches, SPLAT Verb appears to better protect P. albicaulis from D. ponderosae.

Supplementary Materials

Phlebotomine sand flies are worldwide vectors of Leishmania parasites as well as other bacterial and viral pathogens. Due to the variable impact of traditional vector control practices, a more ecologically based approach is needed. The goal of this study was to isolate bacteria from the most attractive substrate to gravid Phlebotomus papatasi Scopoli sand flies and determine the role of bacterial volatiles in the oviposition attractancy of P. papatasi using behavioral assays. We hypothesized that gravid sand flies are attracted to bacterially derived semiochemical cues associated with breeding sites. Bacteria were isolated from a larvae-conditioned rearing medium, previously shown to be highly attractive to sand flies. The isolated bacteria were identified by amplifying and sequencing 16S rDNA gene fragments, and 12 distinct bacterial species were selected for two-choice olfactometer bioassays. The mix of 12 bacterial isolates elicited strong attraction at the lower concentration of 107 cells per ml and significant repellence at a high concentration of 109 cells per ml. Three individual isolates (SSI-2, SSI-9, and SSI-11) were particularly attractive at low doses. In general, we observed dose-related effects, with some bacterial isolates stimulating negative and some positive dose–response curves in sand fly attraction. Our study confirms the important role of saprophytic bacteria, gut bacteria, or both, in guiding the oviposition-site selection behavior of sand flies. Identifying the specific attractive semiochemical cues that they produce could lead to development of an attractive lure for surveillance and control of sand flies.

Lychnophora ericoides is a Brazilian folk phytomedicine from Cerradoʼs “campus rupestris”. Its volatile organic compounds includes bisabolene-derivatives as major compounds. Herein we provide the chemical profiling of constitutive volatile sesquiterpenes from L. ericoides leaves, timeframe emissions surveys, and pollinators records. In situ samples of L. ericoides were harvested. A headspace-solid phase micro extraction method of pre-concentration was optimized. Identification was done through GC-MS. Isolation and structural elucidation were performed whenever necessary. Pollinators were registered in pictures and video. Short time-series and harmonic regressions determined rhythms of single compounds, and average chromatographic signal area was used to determine mono and sesquiterpene rhythms. Concluding, optimized headspace-solid phase micro extraction method of terpenes level analysis was reached. α-Pinene, β-pinene, α-terpinene, para-cymene, limonene, γ-terpinene, terpinen-4-ol, dehydro-sesquicineole, and β-guaiene were identified using GC-MS data. 11-dehydro cadinol and ortho-acetoxy bisabolol were elucidated. Sesquiterpenes concentrations were higher due to temperature rise, lower leaf age, and flowering seasons. Harmonic regressions determined that daylight might control levels of terpenes. Hummingbird, hemiptera insects, and wasps were recorded visiting Compositae capitulum for the first time. We studied nondomestic plants from in situ conditions and concluded that bisabolene-derivative levels were more abundant than monoterpenes during flowering throughout the summer.

The southern pine beetle,Dendroctonus frontalisZimmermann (Coleoptera: Curculionidae: Scolytinae), is among the most destructive bark beetle pests of pines (Pinaceae) of the southeast and mid-Atlantic United States of America, Mexico, and Central America. Numerous volatile compounds can stimulate or reduce attraction of the beetle, but efforts to incorporate these into effective, practical technologies for pest management have yielded mixed results. Attractants have been incorporated into lures used in monitoring traps that are employed operationally to forecast outbreaks and detect emerging populations. The attraction inhibitor, verbenone, shows efficacy for suppressing southern pine beetle infestations but has not yet been adopted operationally. No effective semiochemical tree protectant has been developed for the beetle. We discuss complexities in the chemical ecology of the beetle that likely have impeded research and development of semiochemical management tools, and we describe basic science gaps that may hinder further progress if not addressed. We also report some supporting, original experimental data indicating (1) that a verbenone device can inhibit the beetle’s response to sources of attractant in a radius of at least several metres, (2) similar olfactory responses by the beetle to both enantiomers of verbenone, and (3) that pheromone background can cause conflicting results in semiochemical field tests.

This paper is intended as an assessment of the state of knowledge and development of semiochemical methods for control of bark beetles (Coleoptera: Curculionidae) in western North America and as a roadmap for future research and development in this field. It is based on a keynote presentation given at the symposiumManaging Bark and Ambrosia Beetles with Semiochemicals, held in 2018 in Vancouver, British Columbia, Canada, at the Joint Meeting of the Entomological Society of America, the Entomological Society of Canada, and the Entomological Society of British Columbia. We describe currently available active ingredients, formulations, and release devices. Furthermore, we describe the most urgently needed new products and techniques, and constraints to their further development. Finally, we speculate about opportunities afforded by new advances in microbial synthesis of semiochemicals, streamlining of regulatory processing, and aerial application using unmanned aerial vehicles.

Trypodendron retusum (LeConte) (Coleoptera: Curculionidae: Scolytinae) females excised from newly attacked trembling aspen, Populus tremuloides Michaux (Salicaceae), were shown for the first time to produce the aggregation pheromone (+)-lineatin. Coupled gas chromatographic-electroantennographic detection analysis (GC-EAD) disclosed that the antennae of T. retusum, as well as the antennae of three sympatric species, native T. lineatum (Olivier) and T. rufitarsus (Kirby) and exotic T. domesticum (L.), respond to synthetic (+)-lineatin, but not the (−) enantiomer. In contrast, the antennae of T. betulae Swaine responded to SR- and RR-linalool oxide pyranoid and did not detect lineatin. GC-EAD analysis of volatiles from host and nonhost tree species revealed that conifer-produced α-pinene and angiosperm-produced conophthorin and salicylaldehyde were perceived by the antennae of all three native lineatin-perceiving species, suggesting behavioral activity. Field trapping experiments showed that salicylaldehyde synergized the response of coastal, but not interior, T. retusum to lineatin and inhibited the response of T. lineatum and T. rufitarsus. In the absence of salicylaldehyde, α-pinene appeared to inhibit the response of interior T. retusum to lineatin, while for T. lineatum and T. rufitarsus it had an apparent positive additive or synergistic effect. No behavioral response occurred to conophthorin. The results provide evidence for semiochemical-based reproductive isolation between T. retusum and T. betulae, and between these two angiosperm-infesting species and the two conifer-infesting species. They do not explain how isolation could be maintained between T. lineatum and T. rufitarsus.

The walnut twig beetle, Pityophthorus juglandis Blackman, and its associated fungal pathogen that causes thousand cankers disease, currently threaten the viability of walnut trees across much of North America. During a 2011 assessment of seasonal flight patterns of P. juglandis with yellow sticky traps baited with the male-produced aggregation pheromone component, 3-methyl-2-buten-1-ol, dramatically reduced catches were recorded when Tree Tanglefoot adhesive was used to coat the traps. In summer 2011, two trap adhesives were tested for potential repellency against P. juglandis in a field trapping bioassay. SuperQ extracts of volatiles from the most repellent adhesive were analyzed by gas chromatography–mass spectrometry, and limonene and α-pinene were identified as predominant components. In field-based, trapping experiments both enantiomers of limonene at a release rate of ~700 mg/d conferred 91–99% reduction in trap catches of P. juglandis to pheromone-baited traps. (+)- and (‒)-α-Pinene reduced trap catch by 40 and 53%, respectively, at the highest release rate tested. While a combination of R-(+)-limonene and (+)-α-pinene resulted in a 97% reduction in the number of P. juglandis caught, the combination did not consistently result in greater flight trap catch reduction than individual limonene enantiomers. The repellent effect of limonene may be valuable in the development of a semiochemical-based tool for management of P. juglandis and thousand cankers disease.

Diverse methods have been used to sample insect semiochemicals. Sampling methods can differ in efficiency and affinity and this can introduce significant biases when interpreting biological patterns. We compare common methods used to sample tephritid fruit fly rectal gland volatiles (‘pheromones’), focusing on Queensland fruit fly, Bactrocera tryoni. Solvents of different polarity, n-hexane, dichloromethane and ethanol, were compared using intact and crushed glands. Polydimethylsiloxane, polydimethylsiloxane/divinylbenzene and polyacrylate were compared as adsorbents for solid phase microextraction. Tenax-GR and Porapak Q were compared as adsorbents for dynamic headspace sampling. Along with compounds previously reported for B. tryoni, we detected five previously unreported compounds in males, and three in females. Dichloromethane extracted more amides while there was no significant difference between the three solvents in extraction of spiroacetals except for (E,E)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane for which n-hexane extracted higher amount than both dichloromethane and ethanol. Ethanol failed to contain many of the more volatile compounds. Crushed rectal gland samples provided higher concentrations of extracted compounds than intact rectal gland samples, but no compounds were missed in intact samples. Of solid phase microextraction fibers, polyacrylate had low affinity for spiroacetals, ethyl isobutyrate and ethyl-2-methylbutanoate. Polydimethylsiloxane was more efficient for spiroacetals while type of fiber did not affect the amounts of amides and esters. In dynamic headspace sampling, Porapak was more efficient for ethyl isobutyrate and spiroacetals, while Tenax was more efficient for other esters and amides, and sampling time was a critical factor. Biases that can be introduced by sampling methods are important considerations when collecting and interpreting insect semiochemical profiles.

The leaf skeletonizer, Eutectona machaeralis (Walker) (Lepidoptera: Crambidae), is a severe insect pest of teak trees (Tectona grandis L.f.) in China. To provide some basic evidence for future semiochemical-based management strategies of E. machaeralis, the morphology, ultrastructure, and distribution of antennal sensilla of adults were observed under scanning and transmission electron microscopy. The shape and structure of antenna were similar between males and females, both being filiform. However, the antennal length of males was significantly longer than that of females. Eight morphological sensilla types were observed in both sexes: Bohm's bristles, sensilla trichodea, sensilla basiconica, sensilla chaetica, sensilla styloconica, sensilla coeloconica, sensilla auricillica, and sensilla squamiformia. Significant sexual dimorphism of the sensilla dimensions was found, especially in sensillar length. The putative and potential functions of the different sensilla types are discussed based on the fine structures of the cuticular walls and dendrites of the different sensilla types. We expect these results to help lay a solid foundation for future functional research and develop further investigations of E. machaeralis.

Infection with malarial parasites renders hosts more mosquito-attractive than their uninfected, healthy counterparts. One volatile organic compound, α-pinene, is associated with Plasmodium spp. infection in multiple studies and is a known mosquito attractant. However, how malarial infection results in elevated levels of host-associated α-pinene remains unclear. One study suggested that exposure of erythrocytes to the malarial metabolite (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP) results in increased levels of α-pinene. Here we establish that endogenous levels of α-pinene are present in human erythrocytes, that these levels vary widely by erythrocyte donor, and that α-pinene levels are not altered by HMBPP treatment.

Thrips species (Thysanoptera: Thripidae) cause superficial, brown colored scars and discoloration called silvering on the surface of nectarine fruit which reduce market quality. In cases of high thrips populations, cracking and splitting of the fruit in accompany to superficial damage causes the fruit to be discarded. The study which was based on non-chemical control of thrips species was conducted in a commercial nectarine orchard in Tarsus county of Mersin province in 2013 and 2014. In the study, pest management effect of mass trapping by yellow colored sticky traps baited with semiochemical-kairomone and pheromone-were detected. Each semiochemical was tested in a particular plot. One baited trap per tree was hung at both kairomone and pheromone plots and one bait-free trap per tree at the control plot. The traps were all hung at the pink bud period and were recovered after harvest. The amount of thrips adult and larvae in the flower buds were checked 4-7 day intervals and the traps were checked weekly to count the individuals caught on traps. The results showed that the lowest number of thrips was detected in nectarine flowers in the kairomone plot and kairomone-baited traps captured the highest number of thrips adults. To the contrary, flowers taken from the control plot had the highest number of thrips and control traps captured the lowest number of thrips adults. The success of mass trapping by adding semiochemicals to sticky traps was evaluated by comparing fruit damage in baited and unbaited trap plots by observing 100 fruits on each of five replicate trees for 500 fruit total at each plot before harvest. The fruit damage was 9.0% and 9.8% in the kairomone plot and was 11.2% and 18.2% in the pheromone plot while it was 23.4% and 20.0% in the control plot in years 2013 and 2014 respectively. Mass trapping by baited traps for thrips control in nectarine orchards seems to be encouraging for integrated pest management especially when considering the easily occurring pesticide resistance of thrips species.

Three species of ambrosia beetles (Trypodendron lineatum (Olivier), Gnathotrichus sulcatus (LeConte), and G. retusus (LeConte) (Coleoptera: Curculionidae: Scolytinae)) have been estimated to cause annual losses of $95–$189 million in degrade of logs and lumber on the British Columbia coast, in Canada. A consultant-run semiochemical-based integrated pest management programme was implemented in 1982 against these beetles, following fulfilment of four prerequisites: (1) presence of receptive potential clients, (2) availability of semiochemical lures, (3) invention of an operational trap, and (4) proof of concept of mass trapping technology. The programme is based on two broad strategies: maintain the problem at a tolerable level and, if necessary, reduce the problem to a tolerable level. One measure of effectiveness over 12 years of mass trapping at a dryland sort near Sooke, on Vancouver Island, British Columbia, was 16.4 million beetles trapped and an estimated five to one benefit-to-cost ratio. Despite success, several factors have conspired to reduce the programme from 50 sites serviced in early years to 7 in 2018. Timber companies in British Columbia are currently showing renewed interest and are taking steps to incorporate the integrated pest management programme as a formal component of their overall operations.

The wood-boring larvae of longhorned beetles (Coleoptera: Cerambycidae) can be important pests of woody plants, particularly as invasive species introduced by international commerce. Previous research has revealed that cerambycid species native to different parts of the world often share the same aggregation-sex pheromones and that pheromones of different species can be combined to create multi-species attractants that would be advantageous for surveillance monitoring for a number of species simultaneously. To explore the extent to which these chemicals can be combined into single lures, we developed four different blends of six to eight compounds and tested their effects as attractants for a community of longhorned beetle species in Iowa. The blends included known pheromones of species native to the study site, as well as pheromones identified from cerambycid species native to other parts of the world. The experiment confirmed that several cerambycid species were attracted by specific blends, in accordance with their known pheromone chemistry, and despite the presence of pheromone components of heterospecifics. This finding lends further support to developing multi-component blends that can effectively monitor for new incursions of multiple exotic species concurrently.

1. Significant research has been devoted to the development of semiochemical repellents for mountain pine beetle Dendroctonus ponderosae Hopkins. Several formulations of the beetle's antiaggregation pheromone verbenone (4,6,6‐trimethylbicyclo[3.1.1]hept‐3‐en‐2‐one) are registered to protect pine trees and stands. 2. We compared the efficacy of verbenone and Verbenone Plus for protecting individual lodgepole pine Pinus contorta Dougl. ex Loud. and small stands of P. contorta from mortality attributed to D. ponderosae . Verbenone Plus is a blend of semiochemicals [(−)‐verbenone, acetophenone, and (E )‐2‐hexen‐1‐ol + (Z )‐2‐hexen‐1‐ol] originally developed to inhibit aggregation of western pine beetle D. brevicomis LeConte. It is the only effective semiochemical repellent that protects ponderosa pine P. ponderosa Dougl. ex Laws. from mortality attributed to D. brevicomis , but has yet to be registered or commercialized. 3. Both verbenone and Verbenone Plus were effective for protecting individual P. contorta and small stands of P. contorta from mortality attributed to D. ponderosae . Verbenone alone was as effective as Verbenone Plus. 4. An obstacle to the broader use of semiochemical repellents for the management of bark beetles is the relatively high cost and specificity of the semiochemicals involved. A semiochemical repellent with efficacy across multiple bark beetle species and hosts, such as Verbenone Plus, would be desirable, assuming the additional components are not cost‐prohibitive or limit registration.

There is increasing evidence that microorganisms emit a wide range of volatile compounds (mVOCs, microbial volatile organic compounds) that act as insect semiochemicals, and therefore play an important role in insect behaviour. Although it is generally believed that phylogenetically closely related microbes tend to have similar phenotypic characteristics and therefore may elicit similar responses in insects, currently little is known about whether the evolutionary history and phylogenetic relationships among microorganisms have an impact on insect‐microbe interactions. In this study, we tested the hypothesis that phylogenetic relationships among 40 Bacillus strains isolated from diverse environmental sources predicted mVOC composition and the olfactory response of the generalist aphid parasitoid Aphidius colemani . Results revealed that phylogenetically closely related Bacillus strains emitted similar blends of mVOCs and elicited a comparable olfactory response of A. colemani in Y‐tube olfactometer bioassays, varying between attraction and repellence. Analysis of the chemical composition of the mVOC blends showed that all Bacillus strains produced a highly similar set of volatiles, but often in different concentrations and ratios. Benzaldehyde was produced in relatively high concentrations by strains that repel A. colemani , while attractive mVOC blends contained relatively higher amounts of acetoin, 2,3‐butanediol, 2,3‐butanedione, eucalyptol and isoamylamine. Overall, these results indicate that bacterial phylogeny had a strong impact on mVOC compositions and as a result on the olfactory responses of insects.

The host selection behaviour of the walnut twig beetle, Pityophthorus juglandis , was assessed by monitoring the landing rates of the beetles with sticky sheet traps on the host and nonhost hardwood branches. Sticky sheet traps were deployed for 8 weeks from 6 June to 2 August. 2017 in the Putah Creek Riparian Reserve, Davis, CA . Branches from host northern California black walnut, Juglans hindsii , were paired with branches from six nonhost hardwood species. The landing rate of P . juglandis (412 beetles trapped/8 weeks; 389 on host branches, 23 on nonhost branches) was significantly greater on the host branches for all nonhost hardwoods except Populus fremontii . Proportional comparisons of beetle presence also revealed a significant preference for the host branches compared with all but two nonhost species, Acer negundo and P . fremontii . Capturing P . juglandis without the use of an aggregation pheromone was a rare event, underscoring the difficulty of studying the initial phases of host selection behaviour in bark beetles. Unbaited funnel traps adjacent to selected host trees in the experiment only captured five individuals over a 19‐week period. None were captured in traps adjacent to nonhost trees. This study provided evidence that P . juglandis discriminates between host and nonhost branches while in‐flight. This directed flight behaviour is likely informed by the recognition of both host and nonhost volatile cues. This study established an ecological context for the development of a semiochemical‐based repellent system for protecting walnut trees from future attacks from this invasive bark beetl

To better understand the semiochemical detection and reception mechanisms that involved in intra- and interspecific communication, host selection and mating behavior of Echinothrips americanus (Thysanoptera: Thripidae), scanning electron microscopy was used to examine the external morphology, distribution and ultrastructure of the sensilla on antennae and mouthparts. According to serial SEM images, seven types of antennal sensilla in total were observed in both sexes. Sensilla on mouthparts were observed concentrating on the maxillary palps, labial palps, and paraglossa, which is consistent with the previous conclusions. Possible function of the external sensilla is also discussed.

The search for mates and food is mediated by volatile chemicals. Insects sense food odorants and sex pheromones through odorant receptors (ORs) and pheromone receptors (PRs), which are expressed in olfactory sensory neurons. Molecular phylogenetics of ORs, informed by behavioral and functional data, generates sound hypotheses for the identification of semiochemicals driving olfactory behavior. Studying orthologous receptors and their ligands across taxa affords insights into the role of chemical communication in reproductive isolation and phylogenetic divergence. The female sex pheromone of green budworm moth Hedya nubiferana (Lepidoptera, Totricidae) is a blend of two unsaturated acetates, only a blend of both elicits male attraction. Females produce in addition codlemone, which is the sex pheromone of another tortricid, codling moth Cydia pomonella. Codlemone also attracts green budworm moth males. Concomitantly, green budworm and codling moth males are attracted to the host plant volatile pear ester. A congruent behavioral response to the same pheromone and plant volatile in two tortricid species suggests co‐occurrence of dedicated olfactory channels. In codling moth, one PR is tuned to both compounds, the sex pheromone codlemone and the plant volatile pear ester. Our phylogenetic analysis finds that green budworm moth expresses an orthologous PR gene. Shared ancestry, and high levels of amino acid identity and sequence similarity, in codling and green budworm moth PRs offer an explanation for parallel attraction of both species to the same compounds. A conserved olfactory channel for a sex pheromone and a host plant volatile substantiates the alliance of social and habitat signals in insect chemical communication. Field attraction assays confirm that in silico investigations of ORs afford powerful predictions for an efficient identification of behavior‐modifying semiochemicals, for an improved understanding of the mechanisms of host plant attraction in insect herbivores and for the further development of sustainable insect control., Hedya nubiferana (a tortricid moth on apple and other rosacean plants) is attracted to the sex pheromone and to the plant‐derived kairomone of codling moth (another tortricid moth feeding on apple). A conserved odorant receptor is the basis for this coincidence, which demonstrates the interaction of social signals and food cues in insect herbivores.

Southern pine beetle (Dendroctonus frontalis Zimmermann) and black turpentine beetle (Dendroctonus terebrans Olivier) are two sympatric bark beetle pests of the southeastern United States of America that adversely affect pine (Pinus spp.) health. Successful host tree colonization and reproduction is dependent on a chemical communication system that includes compounds produced by both the beetles and their host trees. To better understand the role of host volatiles in the ecology of these species, we (1) used coupled gas chromatography-electroantennographic detection (GC-EAD) to analyze olfactory sensitivity of D. frontalis and D. terebrans to volatile constituents of host resin, and (2) investigated olfactory stimulants for behavioral effects on both pest species and a major predator, Thanasimus dubius Fabricius (Coleoptera: Cleridae) in field trapping studies. In GC-EAD analyses of the headspace of fresh host resin, antenna of both D. frontalis and D. terebrans produced strongest responses to alpha-pinene, beta-pinene, myrcene, and 4-allylanisole. Field tests indicated that alpha-pinene, beta-pinene, and 4-allylanisole significantly enhanced attraction of D. frontalis, D. terebrans, and T. dubius to traps baited with attractive pheromone components of both bark beetle species, and myrcene diminished this response for D. frontalis. The observed attractive synergism of 4-allylanisole contrasts with previously reported repellency of this compound for D. frontalis and instead suggests this semiochemical may have multiple ecological roles for this species. Lures used for monitoring D. frontalis may be enhanced in sensitivity by adjusting the composition of their host odor components.

Parthenium hysterophorus Linnaeus (Asteraceae) is a toxic weed found abundantly in major agroecosystems of the world. The weed is inhabited by both phytophagous Chrysomelidae (Coleoptera), used as biocontrol agents, and the predaceous Coccinellidae (Coleoptera). The present investigation was designed to assess the feeding attributes and larval development of Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae) in the presence of semiochemical tracks of coccinellid beetles. Results revealed that the presence of coccinellid semiochemical tracks on the weed reduced larval consumption rates, conversion efficiencies, and growth rates. The feeding deterrent effects of the semiochemical tracks were species specific. Larvae accumulated lower concentrations of glucose, proteins, and triacylglycerols and exhibited reduced body biomass in the presence of semiochemical tracks. The coccinellid semiochemical tracks also promoted Z. bicolorata larvae to accelerate their developmental rates and develop faster than the larvae reared in the absence of semiochemical tracks. While the fourth instars consumed food maximally and were heavier, their food use efficiencies were lower than the other instars. Our findings, therefore, suggest that the presence of semiochemical tracks of coccinellids on P. hysterophorus impedes its biological control by Z. bicolorata larvae.

Dermanyssus gallinae (De Geer 1778), commonly named the poultry red mite (PRM), is considered to be the most harmful ectoparasite in poultry farms in Europe. This species feeds on the blood of laying hens, but spends most of its time hidden in cracks and crevices around hen nests. To control PRM populations in poultry houses, chemical pesticides are currently used; however, concern is growing regarding the harmful residues found in eggs and hens, along with the increased resistance of mites against several compounds. Alternatives to synthetic compounds are now being explored, including vaccines, biological control, physical control and semiochemical control based on the chemical ecology of PRM. This review focused on the different volatile organic compounds (VOCs) identified from D. gallinae and other mite species that have been discovered to control them. Pheromones (aggregation pheromone, sex pheromone and alarm pheromone) and kairomones promoting attraction behaviour in D. gallinae and other mite species are presented, while VOCs from essential oils and plant extracts with repellent properties are also explored. Finally, devices using VOCs on PRM in the field are described, with devices that have been tested on other Acari species being mentioned as potential directions for the future control of PRM.

The cranberry weevil Anthonomus musculus Say is a key pest of highbush blueberries (Vaccinium corymbosum L.) and cranberries (Vaccinium macrocarpon Aiton) in the northeastern United States. Previous studies have reported A. musculus adult attraction to traps baited with the aggregation pheromone of the pepper weevil Anthonomus eugenii Cano, likely because these two weevils share similar pheromone blends that differ only in two components. The A. musculus aggregation pheromone contains (Z)‐2‐(3,3‐dimethylcyclohexylidene) ethanol (Z grandlure II), (Z)‐(3,3‐dimethylcyclohexylidene) acetaldehyde (grandlure III), (E)‐(3,3‐dimethylcyclohexylidene) acetaldehyde (grandlure IV) and (E)‐3,7‐dimethyl‐2,6‐octadien‐1‐ol (geraniol); whereas A. eugenii produces a pheromone blend that includes (E)‐2‐(3,3‐dimethylcyclohexylidene) ethanol (E grandlure II) and (E)‐3,7‐dimethyl‐2,6‐octadienoic acid (geranic acid) in addition to the four A. musculus pheromone components. Here, we hypothesized that differences in pheromone composition between these two species influence A. musculus adult attraction to its aggregation pheromone. To test this, we studied the response of A. musculus to its pheromone blend with and without E grandlure II and geranic acid, a commercial A. eugenii pheromone lure and a no‐lure control in highbush blueberry and cranberry fields in New Jersey and Massachusetts, respectively. Regardless of crop type, A. musculus adults were more attracted to their four‐component pheromone blend and the blend plus geranic acid than the commercial A. eugenii pheromone and the no‐lure controls. The A. musculus pheromone blend plus E grandlure II and the A. eugenii pheromone blend also captured more A. musculus adults than the no‐lure control but not compared to the commercial A. eugenii pheromone. Further analysis showed that A. musculus adults are significantly (~27%) less attracted to their pheromone blend if it contains E grandlure II, although the addition of geranic acid did not affect their response. These findings may help guide future efforts towards the development of behaviour‐based tools to monitor and manage A. musculus.