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Asian citrus psyllid (Diaphorina citri) vectors the bacterium Candidatus Liberibacter asiaticus, the causal pathogen of citrus greening disease that is devastating citrus industries worldwide. Suppressing psyllid populations is crucial to prevent disease spread. An attract-and-kill trap based on psyllid behavior would fill a niche for monitoring and control. To optimize visual attraction of psyllids, the ultraviolet (UV) reflective properties of magnesium oxide (MgO) and/or barium sulfate (BaSO4) were assessed for potential application to a trap surface. Under low UV, high UV and natural sunlight conditions, the reflectance, attraction, and probing behaviors of psyllids were evaluated on surfaces containing magnesium oxide or barium sulfate. Magnesium oxide added to yellow sticky traps enhanced visual response of D. citri. Probing assays demonstrated that magnesium oxide alone or as a mixture with a phagostimulant blend, increased the UV reflectance of substrates, as well as, attraction and probing by psyllids. Results demonstrated that psyllids respond to both short (UV) and long (yellow) wavelengths during orientation, and that these inert compounds can increase UV reflectance and improve attractiveness of an attract-and-kill device.

Recent experiments suggest spatial repellents may significantly reduce biting pressure from host-seeking riceland mosquitoes, such as Anopheles quadrimaculatus, in a warm-humid open-field habitat. However, little is known regarding efficacy of these formulations in partially enclosed spaces where US military personnel may be sheltered or concealed in an operational environment. In this study we investigated the capability of 3 spatial repellents—metofluthrin, linalool, and d-cis/trans allethrin—to reduce mosquito incursion into small open-top enclosures of US military camouflage netting. We found that metofluthrin was more effective in partially enclosed spaces compared with the open field, whereas both linalool and d-cis/trans allethrin provided superior protection in the open. These findings support strategic selection of spatial repellents depending on the environment immediately surrounding the host.

The kudzu bug, Megacopta cribraria, is a key pest of soybean in the United States. Electrophysiological and behavioral responses of adult M. cribraria to kudzu and soybean volatile compounds were examined to identify semiochemicals used for host location. Headspace volatiles collected from undamaged potted plants were analyzed by gas chromatography with electroantennographic detection (GC-EAD). Subsequently, six GC-EAD-active compounds were identified by gas chromatography-mass spectrometry (GC-MS). These six compounds, along with some previously reported insect attractants, were selected for electroantennogram (EAG) assays. The four chemicals that elicited the strongest EAG responses, 1-octen-3-ol, nonanal, benzaldehyde, and ocimene, were selected for evaluation in olfactometer bioassays. Both benzaldehyde and 1-octen-3-ol exhibited dose-dependent responses at higher concentration. Our results provide insight into host location compounds used by adult M. cribraria. These results may be evaluated in future field tests and ultimately useful to develop a semiochemical-based monitoring technique and integrated pest management program for M. cribraria.

BACKGROUND: The African citrus triozid (ACT) Trioza erytreae Del Guercio (Hemiptera: Triozidae) is one of the most devastating pests of citrus with a well‐known role as a vector of the phloem‐limited bacteria (Candidatus Liberibacter africanus) associated with huanglongbing (citrus greening disease), currently considered the world's most serious disease of citrus. Although the pest can successfully develop and reproduce on non‐citrus host plants, there is no documented information on the geometric morphometry of ACT. We determine the effect of host plants on ACT morphometry under controlled laboratory conditions using traditional and geometric analysis. RESULTS: ACT reared on C. limon and Citroncirus spp. was significantly larger than when reared on the other host plant species. ACT reared on C. anisata and C. tangelo was consistently smaller than that reared on M. koenigii and C. sinensis. Based on warped outline drawings, ACT reared on Citroncirus spp. and Murraya koenigii had narrower wings than when reared on C. anisata, C. limon, and C. sinensis with slightly broader wing patterns. CONCLUSION: This study clearly demonstrates that host plant species affect morphometric variation in ACT, which might have a direct impact on fitness parameters of the pest as well as its potential for dispersion. Wing shape and size appear to be useful in separating populations of ACT into different groups. © 2018 Society of Chemical Industry

Asian citrus psyllid, Diaphorina citri Kuwayama, negatively impacts the citrus industry as it transmits Candidatus Liberibacter spp., the causal agent of citrus greening. Monitoring D. citri population levels is critical for management of vectors and citrus greening and is usually through use of yellow sticky traps. In our study, use of odors, odor blends, and visual targets were evaluated to determine whether attraction to yellow sticky traps could be improved. Methyl salicylate consistently increased D. citri attraction to decoy yellow but not to other yellow or yellow/green traps. Addition of a visual target did not enhance attraction to sticky traps. While several chemical blends were evaluated, they did not increase psyllid attraction to decoy yellow traps. The increased attraction to traps with methyl salicylate is promising and may contribute to trapping efficiency under field conditions.

Background Mosquito larvicides provide a source-reduction strategy to diminish adult females that bite and potentially spread pathogens. Demands are mounting for new and innovative effective biorational larvicides, due to the development of resistance to some currently utilized mosquito larvicides, undesirable non-target effects, and US Environmental Protection Agency (EPA) restrictions. Methionine is a human nutrient essential amino acid that unexpectedly has been shown to be a valuable safe pest management tool against select insect pests that possess alkaline gut physiology. The present study evaluated larvicidal toxicity of methionine in several pestiferous mosquito (Diptera: Culicidae) genera. Results Concentration-dependent DL-methionine kinetics assays of survival and pupation were conducted in larvae of Aedes albopictus Skuse, Anopheles quadrimaculatus Say, and Culex tarsalis Coquillett in glass jars. High concentrations of DL-methionine yielded 100% mortality for all test species and prevented pupation at a rate equivalent to Bacillus thuringiensis israelensis (Bti) treatments. Concentration kinetics indicated that An. quadrimaculatus was 10-fold more sensitive to DL-methionine than Ae. albopictus and Cx. tarsalis. Conclusions EPA regulations currently exempt methionine in pesticide formulations applied to agricultural crops. This study demonstrates that methionine is a highly effective mosquito larvicide that can provide a beneficial new biorational, environmentally sustainable tool to control pestiferous mosquitoes. © 2018 Society of Chemical Industry.

A study was conducted in 4 plots within a newly established olive grove in Florida to assess surveillance methods for insects present around the period of olive bloom. Over 99% of thrips collected were Frankliniella bispinosa (Morgan) (Thysanoptera: Thripidae), with occasional collections of predacious Leptothrips pini (Watson) (Thysanoptera: Phlaeothripidae). Collections of thrips using sticky traps or in tap or brush samples were high at the time of bloom, with low numbers before bloom and very low numbers after bloom. No differences in collections were seen among plots for thrips numbers when sampled using sticky cards. However, one plot had higher thrips numbers when sampled using tap and brush samples. Overall, and especially during bloom, blue sticky traps were most attractive, followed by yellow and then white sticky traps. Clear (color-free) traps collected the fewest thrips. Using tap samples, more thrips were collected on the edges than in the middle of the grove. Highly localized high densities of thrips were detected by the tap samples. Although sticky traps were highly effective for collecting thrips, only tap samples detected the localized hot spots. Resumen Se realizo un estudio en 4 parcelas dentro de un huerto de olivos recien establecido en la Florida para evaluar los metodos de vigilancia de los insectos presentes durante el periodo de floracion del olivo. Mas del 99% de los trips colectados fueron Frankliniella bispinosa (Morgan) (Thysanoptera: Thripidae), con colecciones ocasionales del depredador, Leptothrips pini (Watson) (Thysanoptera: Phlaeothripidae). Las colecciones de trips que utilizan trampas adhesivas o en muestreo por golpe o cepillado las plantas fueron altas en el momento de la floracion, con pocos numeros antes de la floracion y numeros muy bajos despues de la floracion. No se observaron diferencias en las colecciones entre las parcelas de los numeros de los trips cuando se tomaron muestras con tarjetas adhesivas. Sin embargo, una parcela tuvo un mayor numero de thrips cuando se tomaron muestras de por golpe o cepillado de las plantas. En general, y especialmente durante la floracion, las trampas pegajosas azules fueron las mas atractivas, seguidas de las trampas pegajosas amarillas y luego blancas. Las trampas transparentes (sin color) recolectaron la menor cantidad de trips. Utilizando muestras de por golpe de la planta, se recolectaron mas trips en los bordes que en el medio del huerto. Las muestras por golpe de la planta detectaron altas densidades de trips muy localizadas. Aunque las trampas adhesivas fueron muy efectivas para recolectar trips, solo las muestras por golpe de la planta detectaron los puntos calientes localizados de trips. View this article in BioOne

A tick survey was conducted to document tick-host associations with Florida (USA) wildlife, and to determine the relative abundance and distribution of ixodid ticks throughout the state. The survey was conducted using collection kits distributed to licensed Florida hunters as well as the examination of archived specimens from ongoing state wildlife research programs. Collected tick samples were obtained from 66% of Florida counties and were collected from nine wildlife hosts, including black bear, bobcat, coyote, deer, gray fox, Florida panther, raccoon, swine, and wild turkey. In total, 4176 ticks were identified, of which 75% were Amblyomma americanum, 14% Ixodes scapularis, 8% A. maculatum, 3% Dermacentor variabilis, and

Combinations of female wingbeat acoustic cues and visual cues were evaluated to determine their potential for use in male Aedes aegypti (L.) traps in peridomestic environments. A modified Centers for Disease control (CDC) light trap using a 350-500 Hz frequency-sweep broadcast from a speaker as an acoustic stimulus, combined with a black poster-board half-cylinder behind the trap as a visual stimulus, captured a significantly greater proportion of males in a laboratory arena during daylight than a CDC trap with the visual stimulus alone or a CDC trap alone without stimuli. Traps of each treatment type captured relatively more males when they were placed at darker positions in the arena. Potential applications are discussed for the incorporation of these findings into trapping programs to reduce transmission of human pathogens vectored by Ae. aegypti.

Diaphorina citri, known as the Asian citrus psyllid (ACP), is the insect vector of a devastating citrus disease (huanglongbing; HLB), which has caused billions of dollars in damage in Florida since its detection in 2005. Data from long-term monitoring programs in two Florida citrus groves were used to assess ACP demography and population ecology, which is needed to implement more effective management strategies for HLB. Seasonal patterns and correlations between ACP density estimates and a suite of environmental and community indicators, previously shown to influence ACP demography, were described and interpreted. Data were evaluated for evidence for spatial clustering and density-dependent recruitment of ACP in a major outbreak event using Taylor power law analysis and by fitting a stochastic Beverton–Holt recruitment model using state-space approach. Strong evidence for density-dependent recruitment and spatial clustering was found and should be considered for future modelling work as it can greatly influence ACP populations by affecting their growth rates, dispersal behaviour and morphology, as well as HLB transmission. Observations of ACP density and dispersion in space and time, along with the estimated parameters from the Beverton–Holt model, suggested that intraspecific competition for resources may initiate both local, then widespread dispersal process, thus affecting grove-wide and area-wide HLB transmission. When these results were synthesised with those of parallel studies, the removal of several of these regulating factors in a single year could lead to widespread disease of the entire crop in a grove, and likely surrounding groves as well. We provide the first field evidence of the consequences of back-to-back ACP colonisation on the rapid spread of the HLB in a grove (a mechanism previously demonstrated in laboratory settings). We stress the importance of proper integrated pest management and area-wide management to prevent such outbreaks.

Mosquito surveillance in remote areas with limited access to canisters of CO2 or dry ice will benefit from an effective alternative CO2 source, such as the natural production of CO2 from yeast fermentation. In this study, we investigate differences in mosquito capture rates from the Centers for Disease Control and Prevention (CDC) light traps baited with dry ice compared with traps baited with yeast fermentation of several carbohydrate sources over 23 trap-nights. Results demonstrated the ability of yeast-generated CO2 to effectively attract mosquitoes to a CDC trap, regardless of carbohydrate source. Total collections of mosquitoes using dry ice were significantly higher than collections from yeast-generated CO2 sources. However, mosquito community structure, i.e., the species and relative capture rate of each species, was represented comparably across collections regardless of CO2 source. Volatiles produced by yeast fermentation were analyzed by carbohydrate source, revealing a suite of compounds, possibly synergistic, enhancing effects with CO2 on mosquito collection capability compared with the amount of CO2 used to attract mosquitoes.

Rhipicephalus sanguineus is a canine tick that infests dogs throughout the world and is frequently found in homes and dog kennels. Management of this tick species is complicated by the presence of resistance to commonly utilized acaricides. Fungal formulations could provide a valuable alternative tool for management and are especially relevant indoors where detrimental environmental effects on fungal spores are of less concern. Two commercially available fungal formulations, one containing Metarhizium anisopliae and the other containing Beauveria bassiana, were compared for time to death and sporulation in nymphal ticks exposed for 60 min in treated filter paper packets. Beauveria bassiana exposure killed ticks faster than M. anisopliae exposure and B. bassiana was more likely to sporulate on tick cadavers than M. anisopliae. To determine whether infected ticks could disseminate fungus to their conspecifics, ticks were marked and treated with fungus before being placed with untreated ticks. Fungus was successfully transmitted from treated to untreated ticks. Mortality of ticks exposed to B. bassiana-exposed conspecifics occurred sooner than for those exposed to M. anisopliae-exposed conspecifics, indicating faster dissemination in the former. Therefore, although both formulations resulted in decreased longevity of ticks compared with the controls, the B. bassiana formulation holds the most promise for direct or indirect application with respect to brown dog tick management.

The fall armyworm (Spodoptera frugiperda) (J. E. Smith) (Lepidoptera: Noctuidae), a major agricultural pest in the Western Hemisphere, has recently become established in Africa and Asia. This highly polyphagous species has potential to economically harm multiple crops. Contributing to this host range are two fall armyworm populations historically called ‘host strains’ that differ in host specificity. Understanding behaviors of the two strains is crucial to effective management of this pest. A major difficulty in such studies is that strains have long been considered morphologically indistinguishable, with molecular markers the only reliable means of identification. However, studies of fall armyworm in Colombia reported strain differences in wing morphology sufficiently large to potentially provide a more economical alternative method to determine strain. This study tested whether a similar phenotypic difference was present in Florida populations using geometric morphometric analysis of 15 anatomical landmarks on forewings of 182 specimens from three habitats associated with different host plants. Principle component and linear discriminant analyses identified significant differences in wing size and shape in comparison of strains from different habitats, but not between strains within the same habitat. Data indicate that apparent strain distinctions in wing phenotype are most likely a secondary consequence of differences in developmental growth patterns on different host plants combined with strain-biased host choice. Furthermore, Florida specimens showed much larger phenotypic overlap than observed for strains from Colombia. Together these findings suggest that wing morphology is probably not a reliable indicator of strain identity in field populations where different host plants are available.

Testing behavioral response to insecticidal volatiles requires modifications to the existing designs of olfactometers. To create a testing apparatus in which there is no chemical memory to confound tests, we detail the technical aspects of a new tool with design influences from other olfactometry tools. In addition, this new tool was used to evaluate a novel formulation of metofluthrin for use as an outdoor residual treatment. After sourcing materials to prioritize glass and metal construction, a modular wind tunnel was developed that hybridizes wind tunnel and olfactometer specifications. Volatile contaminants were removed by strong ultraviolet light within the chamber before and between trials. Repellent trials were conducted with an experimental formulation of metofluthrin and a commercial formulation of esfenvalerate, prallethrin, and piperonyl butoxide (Onslaught Fast Cap) against Aedes albopictus (Skuse). Toxicant vapors were delivered with attractants from a lure with behavioral responses scored 20 min post-exposure. Upwind attraction to the attractant lure and the Onslaught Fast Cap plus lure resulted in 90 and 75% capture, respectively. In contrast, metofluthrin vapors resulted in less than 10% attraction, while also causing repellency, disorientation, knockdown, and mortality effects. Our findings demonstrated that an inert modular wind tunnel was functional for mitigating toxic secondary exposures of spatial repellents amidst complex behavioral analysis in mosquitoes. The resulting observations with formulated metofluthrin positively reinforce the merit of transitioning metofluthrin into expanded roles in mosquito management.

Phytophagous insects, including Asian citrus psyllids (Diaphorina citri Kuwayama), use multiple sensory modalities (vision, olfaction, and gustation,) to locate and accept host plants. We explored incorporation of several sensory cues into a multi-modal attract-and-kill device (AK device) using a three-dimensional shape to increase visibility, as well as elements of color, attractant, phagostimulant, UV reflectant, and toxicant. Attraction of adult D. citri to the device was mediated by a combination of a highly reflective yellow cylinder, a UV reflectant compound (magnesium oxide), and an odorant blend as a short-range attractant. The device surface was coated with a slow-release wax matrix (SPLAT&trade, ) augmented with a phagostimulant consisting of a 3-component blend (formic acid, acetic acid, and para-cymene) and an insecticide (&beta, cyfluthrin). Psyllids landing on the device attempted to feed from the wax matrix, became intoxicated, died, and fell from the device. The device remained fully active over a period of 12 weeks partly because dead psyllids or nontargets did not adhere to the surface as occurs on adhesive yellow sticky cards, the industry standard. Laboratory and field assays showed that the device attracted and killed significantly more adult D. citri than ordinary yellow sticky cards. This device or a future iteration based on the design elements of this device is expected to contribute to sustainable and environmentally appropriate management of D. citri by exploiting the psyllid&rsquo, s innate behavioral responses to visual, olfactory, and gustatory stimuli.

Bed bugs as pests of public health importance recently experienced a resurgence in populations throughout the U.S. and other countries. Consequently, recent research efforts have focused on improving understanding of bed bug physiology and behaviour to improve management. While few studies have investigated the visual capabilities of bed bugs, the present study focused specifically on eye morphology and spectral sensitivity. A 3-D imaging technique was used to document bed bug eye morphology from the first instar through adult and revealed morphological characteristics that differentiate the common bed bug from the tropical bed bug as well as sex-specific differences. Electrophysiological measurements were used to evaluate the spectral sensitivity of adult bed bugs. Male bed bugs were more responsive than females at some wavelengths. Electrophysiological studies provided evidence for at least one photoreceptor with a spectral sensitivity curve peak in the green (λmax 520 nm) region of the spectrum. The broadened long wavelength portion of the spectral sensitivity curve may potentially indicate another photoreceptor in the yellow-green (λmax 550 nm) portion of the spectrum or screening pigments. Understanding more about bed bug visual biology is vital for designing traps, which are an important component of integrated bed bug management.

The mixing of an insecticide with sugar solution creates an oral toxin or insecticidal sugar bait (ISB) useful for reducing adult insect populations. The ability of ISBs to kill the biting midge Culicoides sonorensis Wirth and Jones (Diptera: Ceratopogonidae), a vector of bluetongue virus, epizootic hemorrhagic disease and vesicular stomatitis viruses, was tested. The commercial insecticide formulations (percentage active ingredient) tested included bifenthrin, cyfluthrin, deltamethrin, permethrin, dinotefuran, imidacloprid, thiamethoxam and spinosad. Mortality rates were determined for various concentrations of commercial formulations (0.01, 0.05, 0.1, 1, 2 and 3%) and observed at 1, 4, 10 and 24 h post-exposure to the ISB. In the first set of assays, laboratory-reared midges were fed sugar ad libitum and then exposed to insecticide-treated sugar solutions to measure mortality. The second assay assessed competitive feeding: midges were provided with a control sugar solution (10% sucrose) in one vial, and a sugar and insecticide solution in another. Pyrethroid treatments resulted in the greatest mortality in the first hour at the lowest concentrations and spinosad consumption resulted in the least mortality. Biting midges were not deterred from feeding on the 1% ISB solutions despite the presence of an insecticide-free alternative source of sugar.

BACKGROUND Rhipicephalus sanguineus (Latreille), the brown dog tick, is a veterinary canine and urban pest. These ticks have been found to develop resistance and tolerance to the two commonly used acaricides permethrin and fipronil respectively. We have developed a discriminating concentration that can be used for rapid detection of permethrin and fipronil resistance in brown dog tick populations. The availability of a discriminating concentration for the brown dog tick provides an inexpensive and rapid resistance diagnostic technique that can be used to guide tick management plans for companion animals and aid in the selection of environmental treatment options. RESULTS Establishing the discriminating concentration for permethrin and fipronil in brown dog ticks enables a resistant:susceptible screening. For permethrin the discriminating concentration was set at 0.19%, and for fipronil at 0.15%. Three additional diagnostic concentrations were chosen to evaluate resistance levels when larval tick numbers were available for screening. CONCLUSION Future tick submissions from residences and kennel facilities can be subjected to a single chemical concentration to diagnose resistance, which minimizes time, costs and tick rearing requirements and guides effective control plans. With the standardized use of larval ticks, a client-submission quantity of ideally five engorged females would provide sufficient larval numbers to utilize this technique. © 2015 Society of Chemical Industry

Olives are a potential emerging crop for the state of Florida, USA, and the pest arthropods in commercial groves in the state are under-studied. Thrips (order Thysanoptera) are an almost ubiquitous concern among specialty crop growers in Florida. Yellow and blue sticky card traps were used to survey the canopies of trees in 4 North Central Florida olive groves to determine thrips abundance and distribution over 2 growing seasons. Of the 16 species of thrips identified, most were Frankliniella spp., with Florida flower thrips, Frankliniella bispinosa (Morgan) (Thysanoptera: Thripidae), being the most abundant species for both yr. Yellow traps were more effective for most species of thrips, although several species were more abundant on blue traps. No consistent differences between yr existed. Although overall abundance of flower feeding thrips species coincided with flowering events in the olive orchards, there was insufficient flowering to make statistical correlations between the peak of thrips abundance and flowering events in the olive groves. The results of this study will be useful in informing future economic threshold analyses of Thysanoptera in Florida olive groves. Resumen Las aceitunas son un cultivo potencial emergente para el Estado de la Florida, EE. UU., y los artropodos plagas en los bosques comerciales del estado estan poco estudiados. Los trips (orden Thysanoptera) son una preocupacion casi omnipresente entre los productores de cultivos especializados en la Florida. Se usaron trampas adhesivas amarillas y azules para examinar las copas de los arboles en 4 olivares del norte central de la Florida para determinar la abundancia y distribucion de trips durante 2 temporadas de crecimiento. De las 16 especies de trips identificadas, la mayoria fueron Frankliniella spp., con el trips de flores de la Florida, Frankliniella bispinosa (Morgan) (Thysanoptera: Thripidae), siendo la especie mas abundante para ambos anos. Las trampas amarillas fueron mas efectivas para la mayoria de las especies de trips, aunque varias especies fueron mas abundantes en las trampas azules. No existieron diferencias consistentes entre los anos. Aunque la abundancia general de especies de trips que se alimentan de las flores coincidio con los eventos de floracion en los huertos de olivos, no hubo suficiente floracion para hacer correlaciones estadisticas entre el pico de abundancia de trips y los eventos de floracion en los olivares. Los resultados de este estudio seran utiles para informar futuros analisis de umbral economico de los Thysanoptera en los olivares de la Florida. Key Words: thrips; flower pest; Frankliniella bispinosa; Homalodisca vitripennis; olives; Olea europaea View this article in BioOne

Manipulation of insect behavior can provide the foundation for effective strategies for control of insect crop pests. A detailed understanding of life cycles and the behavioral repertoires of insect pests is essential for development of this approach. A variety of strategies have been developed based on behavioral manipulation and include mass trapping, attract-and-kill, auto-dissemination, mating and host plant location disruption, and push-pull. Insight into application of these strategies for insect pests within Diptera, Lepidoptera, Coleoptera, and Hemiptera/Thysanoptera are provided, but first with an overview of economic damage and traditional control approaches, and overview of relevant behavioral/ecological traits. Then examples are provided of how these different control strategies are applied for each taxonomic group. The future of these approaches in the context of altered crop development for repellency or as anti-feedants, the effects of climate change and the risks of behaviorally-based methods are discussed.

The African citrus triozid (ACT) Trioza erytreae Del Guercio (Hemiptera: Triozidae) is one of the most devastating pests of citrus with a well-known role as a vector of the phloem-limited bacteria (Candidatus Liberibacter africanus) associated with huanglongbing (citrus greening disease), currently considered the world's most serious disease of citrus. Although the pest can successfully develop and reproduce on non-citrus host plants, there is no documented information on the geometric morphometry of ACT. We determine the effect of host plants on ACT morphometry under controlled laboratory conditions using traditional and geometric analysis.ACT reared on C. limon and Citroncirus spp. was significantly larger than when reared on the other host plant species. ACT reared on C. anisata and C. tangelo was consistently smaller than that reared on M. koenigii and C. sinensis. Based on warped outline drawings, ACT reared on Citroncirus spp. and Murraya koenigii had narrower wings than when reared on C. anisata, C. limon, and C. sinensis with slightly broader wing patterns.This study clearly demonstrates that host plant species affect morphometric variation in ACT, which might have a direct impact on fitness parameters of the pest as well as its potential for dispersion. Wing shape and size appear to be useful in separating populations of ACT into different groups. © 2018 Society of Chemical Industry.

Mosquitoes use many cues to assess whether a habitat is conducive for reproduction, possibly including the presence of stimuli from aquatic macrophytes. The effect of water infusions of water hyacinth (Eichhornia crassipes), water lettuce (Pista stratioles), parrotfeather (Myriophyllum aquaticum), and water pennywort (Hydrocotyle umbellata) on mosquito oviposition and attraction was investigated. Gravid Culex quinquefasciatus deposited significantly more egg rafts in water hyacinth, water lettuce, or Bermuda hay (positive control) infusions compared to water, while water pennywort and parrotfeather infusions did not differ from water. In-flight attraction responses of Cx. quinquefasciatus, Aedes aegypti, and Anopheles quadrimaculatus were evaluated. The strongest attraction of gravid Cx. quinquefasciatus and Ae. aegypti occurred in the presence of volatiles from infusions of water hyacinth and water lettuce, which were equal in attractiveness to hay infusion. Water pennywort and parrotfeather infusions were not attractive. Gravid An. quadrimaculatus were not attracted to aquatic plant volatiles. The results suggest that water hyacinth and water lettuce emit volatile chemicals that attract two of three mosquito species tested and stimulate oviposition by Cx. quinquefasciatus, demonstrating that the level of attraction of aquatic plant volatiles varies among species in ways that may have relevance to bait-based detection and control methods.

Mosquito larvicides provide a source-reduction strategy to diminish adult females that bite and potentially spread pathogens. Demands are mounting for new and innovative effective biorational larvicides, due to the development of resistance to some currently utilized mosquito larvicides, undesirable non-target effects, and US Environmental Protection Agency (EPA) restrictions. Methionine is a human nutrient essential amino acid that unexpectedly has been shown to be a valuable safe pest management tool against select insect pests that possess alkaline gut physiology. The present study evaluated larvicidal toxicity of methionine in several pestiferous mosquito (Diptera: Culicidae) genera.Concentration-dependent DL-methionine kinetics assays of survival and pupation were conducted in larvae of Aedes albopictus Skuse, Anopheles quadrimaculatus Say, and Culex tarsalis Coquillett in glass jars. High concentrations of DL-methionine yielded 100% mortality for all test species and prevented pupation at a rate equivalent to Bacillus thuringiensis israelensis (Bti) treatments. Concentration kinetics indicated that An. quadrimaculatus was 10-fold more sensitive to DL-methionine than Ae. albopictus and Cx. tarsalis.EPA regulations currently exempt methionine in pesticide formulations applied to agricultural crops. This study demonstrates that methionine is a highly effective mosquito larvicide that can provide a beneficial new biorational, environmentally sustainable tool to control pestiferous mosquitoes. © 2018 Society of Chemical Industry.

Insects and other animals sometimes modify behavior in response to changes in atmospheric pressure, an environmental cue that can provide warning of potentially injurious windy and rainy weather. To determine if Diaphorina citri (Hemiptera: Liviidae) calling, mate-seeking, and phototaxis behaviors were affected by atmospheric pressure, we conducted analyses to correlate responsiveness with pressure trends over periods up to 48 h before laboratory bioassays. Mean responsiveness increased or decreased depending on the magnitudes and directions of pressure changes measured over different periods up to 24 h before bioassays, and changed differently in calling and mate-seeking bioassays than in phototaxis bioassays. For example, mean responsiveness decreased in mating behavior bioassays but increased in phototaxis bioassays when atmospheric pressure changed more than one standard deviation over a 24-h period. Such a result is consistent with a hypothesis that there may be survival benefits to focusing...

In repeated behaviours such as those of feeding and reproduction, past experiences can inform future behaviour. By altering their behaviour in response to environmental stimuli, insects in highly variable landscapes can tailor their behaviour to their particular environment. In particular, female mosquitoes may benefit from plasticity in their choice of egg-laying site as these sites are often temporally variable and clustered. The opportunity to adapt egg-laying behaviour to past experience also exists for mosquito populations as females typically lay eggs multiple times throughout their lives. Whether experience and age affect egg-laying (or oviposition) behaviour in the mosquito Stegomyia aegypti (=Aedes aegypti) (Diptera: Culicidae) was assessed using a wind tunnel. Initially, gravid mosquitoes were provided with a cup containing either repellent or well water. After ovipositing in these cups, the mosquitoes were blood-fed and introduced into a wind tunnel. In this wind tunnel, an oviposition cup containing repellent was placed in the immediate vicinity of the gravid mosquitoes. A cup containing well water was placed at the opposite end of the tunnel so that if the females flew across the chamber, they encountered the well water cup, in which they readily laid eggs. Mosquitoes previously exposed to repellent cups became significantly more likely to later lay eggs in repellent cups, suggesting that previous experience with suboptimal oviposition sites informs mosquitoes of the characteristics of nearby oviposition sites. These results provide further evidence that mosquitoes modify behaviour in response to environmental information and are demonstrated in a vector species in which behavioural plasticity may be ecologically and epidemiologically meaningful.

Asthevectoroftheglobaldiseaseofcitrusgreeningorhuanglongbing,Asiancitruspysllids,Diaphorina citri Kuwayama (Hemiptera: Liviidae), are the greatest threat to the worldwide citrus industry. Criticalto management ofD. citriandhuanglongbingis optimizationofsurveillancemethodologies. Although phytophagous insects may find host plants by multimodal cues, some appear to primarily use visual cues. In this study, we examined the behavior of Asian citrus psyllids toward light from light-emitting diodes (LEDs) in the insect visible spectrum. The periodicity of attraction of psyllids to visual cues was evaluated in the field (yellow sticky traps) and laboratory (multi-colored LEDs) with a strong peak ofactivity during the afternoon in both the field and the laboratory (both 14:00 to 18:00 hours). In laboratory evaluations of psyllids to differently colored LEDs, strongest attraction was to LEDs emitting ultraviolet (390 nm), green (525 nm), and yellow (590 nm) light. Male and femalepsyllidsdid notdiffersignificantly in theirresponsestovisual cues. Thesefindingsprovide the basis for formulating better traps that reflect UV and yellow light and potentially incorporate UV LEDsformonitoringpsyllids anda betterunderstandingofAsiancitruspsyllid visualbehavior.

Permethrin is a commonly used acaricide for tick control on domestic animals and in residential environments, while fipronil use is restricted to on-animal treatment. Following widespread reports of permethrin and fipronil application failures to control indoor infestations of Rhipicephalus sanguineus (Latreille), the brown dog tick, 31 tick populations were obtained from Florida and Texas for acaricide resistance screening. These field-collected ticks from kennels and residential facilities were challenged with technical grade permethrin and fipronil to create dose response curves that were compared with an acaricide-susceptible strain. Permethrin resistance was successfully screened in nine populations, all of which were resistant or highly resistant. Tick susceptibility to fipronil was conducted on four populations, which were found to be tolerant, with resistance ratios below 10. This is the first documentation of R. sanguineus permethrin resistance and fipronil tolerance in the United States. Potential causes of resistance development and recommendations on future brown dog tick control management plans are discussed.

The attraction of female Aedes aegypti to single compounds and binary compositions containing L-lactic acid and an additional saturated compound from a set of ketones, sulfides, and chloroalkanes was studied using a triple-cage dual-port olfactometer. These chemical classes were studied because of their structural relation to acetone, dimethyl disulfide, and dichloromethane, which have all been reported to synergize attraction to L-lactic acid. Human odors, carbon dioxide, and the binary mixture of L- lactic acid and CO2 served as controls for comparison of attraction responses produced by the binary mixtures. All tested mixtures that contained chloroalkanes attracted mosquitoes at synergistic levels, as did L-lactic acid and CO2. Synergism was less frequent in mixtures of L-lactic acid with sulfides and ketones; in the case of ketones, synergistic attraction was observed only for L-lactic acid combined with acetone or butanone. Suppression or inhibition of attraction response was observed for combinations that contained ketones of C7-C12 molecular chain length (optimum in the C8-C10 range). This inhibition effect is similar to that observed previously for specific ranges of carboxylic acids, aldehydes, and alcohols.

The brown dog tick, Rhipicephalus sanguineus (Latrielle), can be a serious residential pest due to its unique ability, among ticks, to complete its lifecycle indoors. A single engorged and fertilized female tick can oviposit around 4,000 eggs, allowing indoor establishment to be rapid and easy to miss in early-stage infestations. Acaricide treatment is currently the primary method of control, but can be costly and can lead to the development of acaricide resistance in tick populations. Traps of various designs can be used to help monitor and manage populations of indoor pests, such as cockroaches and bed bugs, but there are currently no commercially available traps for use with brown dog tick infestations. This study included a comparison of four commercially available bed bug traps (NightWatch [BioSensory Inc., Putnam, CT], Bed Bug Beacon [PackTite, Fort Collins, CO], ClimbUp [Susan McKnight Inc., Memphis, TN], and Verify [FMC Corporation, Philadelphia, PA]) with regard to their efficacy in capturing brown dog ticks, and also compared tick attraction to ClimbUp traps baited with several stimuli including CO2. Significantly more ticks were captured and attracted to the NightWatch and CO2-baited ClimbUp traps than the other two trap models. The results suggest that bed bug traps may be useful in brown dog tick monitoring, and CO2 will likely be an important component of a trapping system employed in the future.

Mosquitoes of various species mate in swarms comprised of tens of thousands of flying males. In this study, we examined Aedes aegypti swarming behavior and identified associated chemical cues. Novel evidence is provided that Ae. aegypti females aggregate by means of olfactory cues, such as aggregation pheromones. Isolation of Ae. aegypti aggregation pheromones was achieved by aeration of confined mosquitoes and collection of associated volatiles by glass filters. The collected volatiles were identified through gas chromatography mass spectrometry (GCMS). Three aggregation pheromones were collected and identified as 2,6,6-trimethylcyclohex-2-ene-1,4-dione (ketoisophorone) (CAS# 1125-21-9, t R = 18.75), 2,2,6-trimethylcyclohexane-1,4- dione (the saturated analog of ketoisophorone) (CAS# 20547-99-3, t R = 20.05), and 1-(4-ethylphenyl) ethanone (CAS# 937-30- 4, t R = 24.22). Our biological studies revealed that the identified compounds stimulated mosquito behavior under laboratory conditions. The mechanism of mosquito swarm formation is discussed in light of our behavioral study findings. A preliminary field trial demonstrated the potential application of the isolated aggregation pheromones in controlling Ae. aegypti. Journal of Vector Ecology 39 (2): 347-354. 2014.

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a primary pest of citrus due to its status as a vector of the citrus disease, huanglongbing. We evaluated the effects of light of specific wavelength and polarization on phototactic behavior of D. citri using a horizontal bioassay arena. Wavelength-associated positive phototaxis was associated with short wavelength UV (350–405 nm) targets whereas little or no responses were seen in longer wavelength targets in the visible spectrum from green to orange (500–620 nm). Distance walked towards the visual target was greater for UV/blue wavelengths (350–430 nm) than for longer wavelengths. Distances walked towards 365 nm light were greater than to white light, and distances travelled to green, yellow and orange light were similar to those in darkness. A reduced light intensity decreased responses to white and UV (365 nm) light. Polarized light was discriminated and D. citri travelled greater distance in response to white vertically polarized light than to horizontally polarized or unpolarized light of equal intensity. Responses to polarized 405 nm light were greater than to unpolarized light, although without an effect of polarization plane. For 500 nm light, there was no difference between responses to polarized or unpolarized light. There was no effect of age on responses to 405 nm light although 1 day old psyllids travelled faster in the presence of 500 nm green compared to 4–7 day old psyllids. Movement in response to UV and relative stasis in response to longer wavelength light is consistent with observed behaviors of settling on foliage for feeding and dispersing out of the canopy when flush needed for reproduction is scarce.

Mosquito surveillance in remote areas with limited access to canisters of CO

Background Dual attractant toxic sugar baits (D-ATSB) containing two host kairomones, L-lactic (LA) and 1-octen-3-ol (O), and fruit-based attractants were evaluated through olfactory, consumption and mortality, and semi-field experiments to determine if host kairomones could first, enhance attraction of a fruit-based (attractant) toxic sugar bait (ATSB), and second, increase the efficacy of a fruit based attractive toxic sugar bait (ATSB). Methods Four combinations of LA and O were incorporated into the ATSB and evaluated in an olfactometer to determine if these combinations could enhance attraction of Aedes aegypti (L.) to the bait. Ae. albopictus (Skuse) and Ae. aegypti were used to determine bait consumption through excrement droplet counts and percent mortality, of the most attractive D-ATSB (1% LA and 1% O) from the olfactory study. Semi-field evaluations were conducted in screened portable field cages to determine if the D-ATSB applied to non-flowering plants controlled more mosquitoes than the fruit-based ATSB, and ASB. Mosquitoes were exposed to D-ATSB and the two controls for 48 h and collected with BGS traps. The catch rates of the BGS traps were compared to determine efficacy of the D-ATSB. Results During olfactometer evaluations of D-ATSB, Ae. aegypti mosquitoes were more attracted to 1% LA and 1% O compared to the fruit-based toxic sugar bait alone. Both species of mosquito consumed more fruit-based non-toxic bait (ASB) and ATSB than the D-ATSB. For both species, percent mortality bioassays indicated D-ATSB controlled mosquitoes, as compared to non-toxic control, but not more than the fruit based ATSB. Semi-field evaluations, BioGents sentinel traps at 48 h confirmed that ATSB (positive control) controlled Ae. albopictus, but there was no statistical difference between ASB (negative control) and the D-ATSB. No differences were observed between the mosquitoes caught in any of the experimental formulations for Ae. aegypti. Conclusions L-lactic (1%) and 1-octen-3-ol (1%) added to a fruit-based sugar bait increased attraction of Ae. aegypti and may have future implications in mosquito trapping devices. The addition of the host kairomones did not enhance the consumption and efficacy of the ATSB in laboratory or semi-field evaluations for both mosquito species. We attribute to the absence of other host cues leading to lack of alighting onto bait surfaces to imbibe the toxic bait, as well as a possible decrease in palatability of the bait caused by the addition of the host kairomones.

A field strain of Aedes aegypti (L.) was collected from Puerto Rico in October 2008. Based on LD50 values by topical application, the Puerto Rico strain was 73-fold resistant to permethrin compared with a susceptible Orlando strain. In the presence of piperonyl butoxide, the resistance of Puerto Rico strain of Ae. aegypti was reduced to 15-fold, suggesting that cytochrome P450-mediated detoxification is involved in the resistance of the Puerto Rico strain to permethrin. To determine the cytochrome P450s that might play a role in the resistance to permethrin, the transcriptional levels of 164 cytochrome P450 genes in the Puerto Rico strain were compared with that in the Orlando strain. Of the 164 cytochrome P450s, 33 were significantly (P < 0.05) up-regulated, including cytochrome P450s in families four, six, and nine. Multiple studies have investigated the functionality of family six and nine cytochrome P450s, therefore, we focused on the up-regulated family 4 cytochrome P450s. To determine whether up-regulation of the four cytochrome P450s had any functional role in permethrin resistance, transgenic Drosophila melanogaster Meigen lines overexpressing the four family 4 P450 genes were generated, and their ability to survive exposure to permethrin was evaluated. When exposed to 5 microg per vial permethrin, transgenic D. melanogaster expressing CYP4D24, CYP4H29, CYP4J15v1, and CYP4H33 had a survival rate of 60.0 +/- 6.7, 29.0 +/- 4.4, 64.4 +/- 9.7, and 11.0 +/- 4.4%, respectively. However, none of the control flies survived the permethrin exposure at the same concentration. Similarly, none of the transgenic D. melanogaster expressing CYP4J15v1 or CYP4H33 ?5 survived when they were exposed to permethrin at 10 microg per vial. However, transgenic D. melanogaster expressing CYP4D24 and CYP4H29 had a survival rate of 37.8 +/- 4.4 and 2.2 +/- 2.2%, respectively. Taken together, our results suggest that CYP4D24 might play an important role in cytochrome P450-mediated resistance to permethrin.

The efficacy of attractive toxic sugar baits (ATSB) with the active ingredient eugenol, an Environmental Protection Agency exempt compound, was evaluated against vector and nuisance mosquitoes in both laboratory and field studies. In the laboratory, eugenol combined in attractive sugar bait (ASB) solution provided high levels of mortality for Aedes aegypti, Culex quinquefasciatus, and Anopheles quadrimaculatus. Field studies demonstrated significant control: >70% reduction for Aedes atlanticus, Aedes. infirmatus, and Culex nigripalpus and >50% reduction for Anopheles crucians, Uranotaenia sapphirina, Culiseta melanura, and Culex erraticus three weeks post ATSB application. Furthermore, non-target feeding of six insect orders, Hymenoptera, Lepidoptera, Coleoptera, Diptera, Hemiptera, and Orthoptera, was evaluated in the field after application of a dyed-ASB to flowering and non-flowering vegetation. ASB feeding (staining) was determined by dissecting the guts and searching for food dye with a dissecting microscope. The potential impact of ATSB on non-targets, applied on green non-flowering vegetation was low for all non-target groups (0.9%). However, application of the ASB to flowering vegetation resulted in significant staining of the non-target insect orders. This highlights the need for application guidelines to reduce non-target effects. No mortality was observed in laboratory studies with predatory non-targets, spiders, praying mantis, or ground beetles, after feeding for three days on mosquitoes engorged on ATSB. Overall, our laboratory and field studies support the use of eugenol as an active ingredient for controlling important vector and nuisance mosquitoes when used as an ATSB toxin. This is the first study demonstrating effective control of anophelines in non-arid environments which suggest that even in highly competitive sugar rich environments this method could be used for control of malaria in Latin American countries.

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is one of the most serious citrus pests worldwide due to its role as vector of huanglongbing or citrus greening disease. While some optimal plant species for ACP oviposition and development have been identified, little is known of the influence of host plants on ACP size and shape. Our goal was to determine how size and shape of ACP wing and body size varies when development occurs on different host plants in a controlled rearing environment. ACP were reared on six different rutaceous species; Bergera koenigii, Citrus aurantifolia, Citrus macrophylla, Citrus maxima, Citrus taiwanica and Murraya paniculata. Adults were examined for morphometric variation using traditional and geometric analysis based on 12 traits or landmarks. ACP reared on C. taiwanica were consistently smaller than those reared on the other plant species. Wing aspect ratio also differed between C. maxima and C. taiwanica. Significant differences in shape were detected with those reared on M. paniculata having narrower wings than those reared on C. macrophylla. This study provides evidence of wing size and shape differences of ACP based on host plant species which potentially may impact dispersal. Further study is needed to determine if behavioral and physiological differences are associated with the observed phenotypic differences.

Methods were developed for synchronized rearing of unmated and mated Asian citrus psyllid (ACP) ( Diaphorina citri Kuwayama; Hemiptera: Liviidae) of known age in isolation chambers for behavioral studies. Maintenance and survival of nymphs and adults in the isolation chambers was improved over previous methods because the plants had more room to grow and the relative humidity was easier to keep within acceptable limits. Se desarrollaron metodos para la cria sincronizada del psilido asiatico de los citricos (PAC) de edades conocidas, no apareados y apareados ( Diaphorina citri Kuwayama, Hemiptera: Liviidae) en camaras de aislamiento para estudios de comportamiento. El mantenimiento y la sobrevivencia de las ninfas y adultos en las camaras de aislamiento se ha mejorado con respecto a los metodos usados anteriormente, debido a que las plantas tenian mas espacio para crecer y la humedad relativa fue mas facil mantener dentro de los limites aceptables. View this article in BioOne

We evaluated the efficacy of attractive toxic sugar baits (ATSB) in the laboratory and field with the low-risk active ingredient dinotefuran against mosquito populations. Preliminary laboratory assays indicated that dinotefuran in solution with the sugar baits was ingested and resulted in high mortality of female Culex quinquefasciatus Say and Aedes aegypti Linnaeus. Field studies demonstrated >70% reduction of mosquito populations at 3 wk post-ATSB application. Nontarget feeding of seven insect orders—Hymenoptera, Lepidoptera, Coleoptera, Diptera, Hemiptera, Orthoptera, and Neuroptera—was evaluated in the field after application of attractive sugar baits (ASB) on vegetation by dissecting the guts and searching for food dye with a dissecting microscope. Nontargets were found stained with ASB 0.9% of the time when the application was applied on green nonflowering vegetation. Only two families were significantly impacted by the ASB application: Culicidae (mosquitoes) and Chironomidae (nonbiting midges) of the order Diptera. Pollinators of the other insect orders were not significantly impacted. No mortality was observed in the laboratory studies with predatory nontargets, wolf spiders or ground beetles, after feeding for 3 d on mosquitoes engorged on ATSB applied to vegetation. Overall, this novel control strategy had little impact on nontarget organisms, including pollinators and beneficial insects, and was effective at controlling mosquito populations, further supporting the development of ATSB for commercial use.

Ultralow volume droplets of DUET, prallethrin, and sumithrin at a sublethal dose were applied to unfed (nonbloodfed) and bloodfed female Aedes aegypti L. and Aedes albopictus (Skuse) in a wind tunnel. Control spray droplets only contained inert ingredients. Individual mosquitoes were videotaped before, during, and after spraying and various behaviors analyzed. During the spray periods of all three pesticide treatments, mosquitoes spent a greater percentage of time moving, and the distance moved was greater than for mosquitoes in the control treatments. In the postspray period, the percent of time moving increased for mosquitoes exposed to all pesticide treatments compared with the controls. After treatment, all females spent more time walking compared with controls, with unfed Ae. aegypti females walking more after exposure to DUET and sumithrin than after exposure to prallethrin and the control. Pesticide exposure increased flying in both species. Sumithrin exposure increased activity and velocity of unfed mosquitoes more than bloodfed mosquitoes. DUET and sumithrin treatments enhanced activity of Ae. aegypti females more than Ae. albopictus females.