In cleptoparasitic bees, host aggression and detection avoidance might be the main selective pressures shaping host-parasite interactions. However, the behavioral responses toward parasitism are unknown for most host species. In this study, we investigated the host-parasite interactions and behaviors of the cleptoparasitic bee Triepeolus remigatus when parasitizing the nests of its host, the squash bee Xenoglossa (Peponapis) pruinosa. Using circle-tube behavioral assays and direct observations at a nest aggregation of X. pruinosa, we assessed whether interactions between host and parasite were aggressive, tolerant, or avoidant and characterized the general parasitic behavior of T. remigatus. Our results reveal a lack of aggression between host and cuckoo bees, with interactions primarily characterized by tolerant and avoidant behaviors. Squash bees displayed minimal aggression toward both conspecifics and parasites. Interestingly, despite the absence of aggressive responses, T. remigatus preferred entering nests while the host was foraging, potentially indicating a strategy to avoid the discovery of parasitic visits. Furthermore, field observations provided insights into the parasitic behavior of T. remigatus, revealing primarily rapid visits to host nests without extensive inspection. The limited aggression and short time for nest visits observed in T. remigatus suggest adaptations to optimize parasitic success while minimizing host detection. Overall, our findings contribute to a better understanding of the behavior of open-cell parasites and provide a first accounting of the squash bee behavior when encountering parasitic bees. Further research is needed to elucidate the mechanisms underlying host-parasite coevolution and response to parasitism in ground-nesting bees.

In nuisance or vector mosquito management, effective sampling is a stepping stone to efficient use of resources, targeted control efforts, and successful reduction of disease transmission. Experimental evidence indicates that there are species biases for certain traps, which in turn implies that the traps used will influence the species make-up of samples collected. A comparative study between 3 CO2-baited light traps and 2 hay-infusion baited gravid traps-Centers for Disease Control and Prevention (CDC) light trap, American BioPhysics Company (ABC) light trap, Reiter-Cummings (RC) gravid trap, and a convertible gravid/light trap with a novel design-was conducted to test for species specificity of each trap type. It was found that different species of mosquitoes are more likely to be collected in greater numbers with certain traps compared to others, even between the different light traps or gravid traps. In particular, Coquillettidia perturbans tended to be collected in greater numbers with CDC light traps, Culex salinarius tended to be collected in greater numbers with the experimental convertible light traps, and Culex pipiens tended to be collected in greater numbers with the Reiters-Cummings gravid traps over the other traps included in the study (P ≤ 0.05). The overall species richness of samples was comparable among trap types, with similar performance of the new trap designs as established designs (P ≤ 0.05).

The surfaces of trichoid sensilla on male moth antennae have been sculpted over evolutionary time to capture pheromone odorant molecules emitted by the females of their species and transport the molecules in milliseconds into the binding protein milieu of the sensillum lumen. The capture of pheromone molecules likely has been optimized by the topographies and spacings of the numerous ridges and pores on these sensilla. A monolayer of free lipids in the outer epicuticle covers the sensillar surfaces and must also be involved in optimal pheromone odorant capture and transport. Using electro-conductive atomic force microscopy probes, we found that electrical surface potentials of the pores, ridges and flat planar areas between ridges varied in consistent ways, suggesting that there is a heterogeneity in the distribution of surface lipid mixtures amongst these structures that could help facilitate the capture and transport of pheromone molecules down through the pores. We also performed experiments using peak force atomic force microscopy in which we heated the sensilla to determine whether there is a temperature-related change of state of some of the surface lipid exudates such as the prominent domes covering many of the pores. We found that these exudates were unaffected by heating and did not melt or change shape significantly under high heat. Additionally, we measured and compared the topographies of the trichoid sensilla of five species of moths, including the distributions, spacings, heights and diameters of ridges, pores and pore exudates.

The present study was conducted to determine the role of guava fruit volatiles in attraction, oviposition and associated fitness parameters of the peach fruit fly, Bactrocera zonata Saunders, which is a key pest of guava and many other fruits. B. zonata female flies’ attraction was observed in a Y-tube olfactometer using fruits of three locally grown guava varieties; Gola, Larkana Small Surahi (LSS) and Larkana Large Surahi (LLS). Female flies showed significantly higher levels of attraction to both un-infested and infested guava fruit odors compared to control (blank). In pairwise comparisons between different fruit varieties, females B. zonata showed significantly greater levels of attraction towards un-infested Gola compared to un-infested LSS, while in the case of the same variety, significantly higher number of flies were attracted to un-infested compared to infested fruit in all three tested varieties. In two-choice oviposition bioassays, B. zonata females made significantly more visits, greater numbers of ovipositions, spent a significantly longer time, and larger numbers of pupae and adults developed on Gola fruits compared to LSS fruits. However, in no-choice bioassays, females made more visits and spent a significantly greater amount of time on LSS compared to Gola and LLS. GC–MS analysis of guava headspace revealed presence of aliphatic and aromatic esters as a dominant group of compounds in both un-infested and fruit-fly-infested guava fruits, with a higher quantity mostly occurring in fruit-fly-infested fruits. Role of guava volatiles is discussed in an ecological context of attraction and oviposition behaviors of adult females and fitness of their offspring.

A large accumulation of several hundred actively flight-dispersing spotted lanternflies Lycorma delicatula was found on an isolated single telephone pole in a vineyard in Eastern Pennsylvania, USA. Many of the lanternflies flying across the vineyard very near to the pole turned toward and landed on it in an apparent visually mediated response to the tall vertical silhouette, whereas others flew past it. We video-recorded, digitized, and analyzed 481 tracks, of which there were 188 that were behaviorally classifiable with durations greater than 2 s. We found that lanternflies reacted to the 12.5-m-high pole by turning toward it when they were an average of 2.1 m away from it at an average height of 7.8 m. Those that did not react to the pole by turning toward it were at an average distance of 3.6 m from it at a height of 11.5 m. It appears that the object-vision capabilities of the lanternflies to this vertical structure that were intense enough to elicit a behavioral reaction to it were limited to a mean distance of 2.1 m during in-flight approach.

Two odorant receptors (ORs), OnubOR3 and OnubOR6, in the sex pheromone communication systems of E- and Z-strain European corn borers, Ostrinia nubilalis, were broadly receptive to analogs of their pheromone components. In addition to responding to their natural 14-carbon pheromone components, ( Z )-11- and ( E )-11-tetradecenyl acetates (Z11- and E11-14:OAc), these pheromone ORs responded to the longer-chain compounds, ( Z )-11- and ( E )-11-hexadecenyl acetate (Z11- and E11-16:OAc). Z11-16:OAc is a pheromone gland constituent of E-strain O. nubilalis females in Europe but has not previously been shown to have behavioral activity to males. Here, we demonstrate that Z11-16:OAc evokes high levels of upwind flight and source location in E-strain males when substituted for Z11-14:OAc (minor component) in the E-strain blend. Since Z11-16:OAc is found in the gland and has behavioral activity when Z11-14:OAc is missing, then it should be classified as a cryptic, redundant minor pheromone component in E-strain O. nubilalis . The opposite geometric isomer, E11-16:OAc, also functions in Z-strain O. nubilalis , substituting behaviorally for the E11-14:OAc minor component, but has not been found in Z-strain female glands. Single-sensillum recordings showed that sensory neurons of E- and Z-strain male antennae expressing OnubOR3 and OnubOR6 produced responses to these hexadecenyl acetates similar to those evoked by the natural (tetradecenyl acetate) pheromone components. We postulate that the wide responsiveness of these two ORs to the 16-carbon acetates could be a preadaptation for O. nubilalis to use these compounds as minor components in lieu of the respective 14-carbon acetates. Alternatively, the responsiveness of OnubOR3 to E11-16:OAc and OnubOR6 to Z11-16:OAc could represent a vestigial state of these receptors, with the 16-carbon acetates having previously acted as functional minor components in an ancestral blend.

The spotted lanternfly, Lycorma dehcatula, (Hemiptera Fulgoridae) is an invasive pest in Korea and the United States, but originating from mainland Asia. Both tree of heaven, Ailanthus altissima, and grapevine (Vitis) are known to be preferred hosts of adults. However, much is unknown about its adult behavior with respect to mating or dispersal patterns. In 2015, just after it was discovered in the United States, we performed an observational study to elucidate movement by adults in relation to host plants. We noted weekly changes in their presence and sex ratio on host plants at four sites in a quarantine zone in Berks County, PA. Just after adult emergence, the trunks of large ( > 15 cm diameter at breast height) A. altissima hosted nearly exclusively females, while smaller A. altissima, Vitis, Salix nigra, and other less commonly inhabited tree species, had high proportions of males. By October 1st, greater proportions of males were observed on the trunks of the larger A. altissima trees. Pairings of males and females were observed most frequently on the smaller A. altissima and Vitis. At the very end of the season, a large mixed-sex population was found on Salix nigra, which was the only deciduous tree species in the area still bearing green leaves.

Adult spotted lanternflies, Lycorma delicatula, launch themselves into the wind from elevated locations such as trees, lamp posts, and buildings. Individuals fly in short, successive bouts along descending trajectories of between 10 and 50 m before landing, crawling upward on a new structure, and again launching upwind. The possible physiological limits to the durations of flight-bouts, if not constrained by their poor ability to generate lift, however, remain unknown. In this study, we observed the behavior of tethered spotted lanternflies known to be prone to flight-dispersing, and recorded the number and durations of their successive flight bouts. Additionally, we recorded the flight distances and durations of similar spotted lanternflies in the field that had spontaneously taken flight or had been manually launched. We found that tethered females can perform >20 successive bouts with only 1 min between bouts when flight durations were limited to 20 s/bout. Bouts averaged 97.9 ± 11.4 s when bout durations were unlimited, with some females flying bouts lasting >400 s. Females could quickly advance upwind a distance >3000 m if the bouts of ~100 s each were performed in quick succession in the field. However, adults spontaneously taking flight in the field flew for an average of only ~13 s and traveled an average of ~29 m before landing on the ground or on nearby objects. This information is important to determine how far a locally dispersing adult can fly before finding a suitable host to finish feeding and attain reproductive maturity.

Ticks can vector and transmit many pathogens and pose a serious human health threat throughout the world. After collection, many diagnostic laboratories must mechanically disrupt tick specimens for diagnostic testing and research purposes, but few studies have evaluated how well-commercial tissue homogenizers perform this task. We evaluated four commercially available tissue homogenizers:The Bead Ruptor 24 Elite, the Bullet Blender Storm, the gentleMACS Dissociator, and the Precellys 24. We quantitatively compared maceration level, nucleic acid quality, quantity, amplification, and DNA shearing to determine which machines performed the best. The Bead Ruptor 24 Elite had the highest overall score when disrupting a single, uninfected adult Amblyomma americanum (Linnaeus) (Ixodida: Ixodidae) and performed well in follow-on tests including disrupting individual juvenile samples and detecting pathogens from infected samples.

During the summer and fall of 2017 in northeastern Pennsylvania we studied the progression of adult behaviors of the spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae) when there was an upsurge in adult flight behavior that was not known to have occurred in 2015 or 2016, the first years following its initial detection in Pennsylvania in late 2014. Sex ratios on A. altissima trunks and branches were routinely ca. 50:50 male:female throughout the 2017 season except in two instances in two of the earliest samplings in which >60% were males. Within the first week after adult eclosion in 2017, in conjunction with extensive feeding-related behaviors on Ailanthus altissima tree trunks, short flights occurred indiscriminately from the foliage of one tree to another or between bushes, trees and vines. One week later these flights became more prevalent and lengthier. Adults of both sexes launched themselves into the wind from non-host trees or from porches, posts and other human-made structures to engage in level or gradually descending straight-line flight trajectories that allowed them to traverse only usually 10 to 40 m of ground in one episode. After the peak of flight dispersal had occurred, the first mating pairs were observed on September 25. All of the 21 pairs of adults we observed in copula exhibited swollen, yellow abdomens in contrast to the thinner, predominantly black abdomens of the adults we had sampled during the earlier feeding and flight phases. Copulating pairs were observed to remain coupled for 2 to 4 h.

The effect of delayed female mating for the mushroom fungus gnat Lycoriella ingenua is investigated. We examine the effect of delaying female mating on the fertility and egg viability of female flies that have a mating delay of 0-5 days after emergence. Male fly age is held constant. Female age does not impact male acceptance and most flies copulate within seconds of pairing. We find that female flies experiencing mating delays of 0-4 days after emergence lay a similar number of eggs onto artificial substrates. Females that experience a mating delay of 5 days lay 54% fewer eggs than those that mate on day 0 (day of emergence). There is no effect of mating delay on the percentage of larvae that emerge. The results of the present study indicate that mating delays have little effect on the fertility or fecundity of the mushroom fungus pest L. ingenua.

The spotted lanternfly, Lycorma delicatula (White), is an orchard and forest pest native to China. Since its detection in Pennsylvania, USA in 2014, it has spread to other states as well. We conducted experiments to determine the flight capabilities of unmated vs. mated L. delicatula females to assess the relative threat posed by each type with regard to expanding the infestation area through their natural flight behaviors. Females were collected from mating pairs, captured on plants, and netted during flights averaging 24 m, then dissected and examined for male spermatophores, a diagnostic character for determining mating status. The weight, amount of yellow area on the abdomen, wing area, and body length and abdominal width was recorded from these females. Sedentary females on plants were selectively collected for their large and swollen abdomen. They were capable of only flying ~4 m when forcibly launched and were significantly heavier than the in-flight-captured females. More than 93% of these large, sedentary females had mated whereas <5% of the flight-captured females had mated. Spontaneously flying females weighed significantly less, and had significantly smaller and less yellowed abdomens than sedentary plant-captured females. We conclude that nearly all the observed spontaneously flying L. delicatula females were unmated and therefore pose a lower threat to spread the infestation than previously thought. We also hypothesize that these thinner, spontaneously flying females embark on these 10–50-m-long flights because they need to find new trees on which to feed to complete their egg maturation in order to oviposit successfully.

The spotted lanternfly, Lycorma delicatula, (Hemiptera, Fulgoridae) is an invasive pest to Korea and the United States, originating from China or Southeast Asia. Immature L. delicatula feed on a wide range of plants, but the adults are more host-selective, often preferring the tree of heaven, Ailanthus altissima. We performed field studies to evaluate adult movement in relation to A. altissima after disturbance. The Ailanthus trees were in a mixed suburban forested situated at the southern border of an open grassy field. Female adult lanternflies were manually disturbed from feeding on the trunks of large A. altissima trees. In the first experiment, insects were disturbed directly from the tree using a ballpoint pen to simulate a predatory attack. These insects usually flew initially southward away from the tree line toward a sunlit field, but turned northward back toward the tree line. In the second experiment, to simulate an initially successful predatory attack, they were manually taken from trees, and allowed to escape. The females immediately opened their wings in an apparent aposematic display. They then either immediately flew toward the sunlit open field, or remained with their wings splayed open for a prolonged period.

Electrophysiological recordings from the labial and maxillary palps of the Asian longhorned beetle, Anoplophora glabripennis, revealed their ability to detect several volatile chemicals, including water vapor and acetic acid. The results indicate that these appendages may play a large role in this beetle's assessment of its immediate environment. A. glabripennis is a highly destructive, invasive pest that feeds preferentially on maple - but accepts many other tree species - in North America, warranting USDA quarantine zones and an eradication program. While control and sampling techniques are being developed for this insect, a better understanding of its sensory capabilities is helpful. Electropalpograms (EPGs) revealed that both the maxillary and labial palps are highly sensitive to changes in humidity, indicating the presence of hygroreceptors and the likely important role of humidity in such things as feeding and finding water or oviposition sites. Strong EPG responses to a narrow set of volatile chemicals indicate that olfactory sensory neurons (OSNs) on the palps may be tuned to a small number of volatile compounds. The types of odorant molecules eliciting responses indicate that there are likely both odorant receptors (ORs) as well as ionotropic receptors (IRs) expressed on the OSNs, enabling palp OSNs to be able to respond to acids and aldehydes such as acetic acid and butyraldehyde. There were no significant EPG responses to this species' trail-sex pheromone components, which may indicate that the trail pheromone is primarily perceived via gustatory receptors contacting the substrate. These results indicate that the palps have a role in the beetle's assessment of its immediate environment underfoot, and that the sampling of surface odors and humidity via mouth parts may be important to this species' success.

The mushroom phorid fly, Megaselia halterata (Wood) (Diptera: Phoridae), is a key pest in mushroom farming in most parts of the world. Studies on the mushroom phorid fly have focused on its life history within mushroom growing houses, but little is known about the fly's activity outside mushroom growing houses. In this study, daily activity and distribution of adult M. halterata in the areas surrounding mushroom growing houses was studied using yellow sticky traps. Results suggest that M. halterata focuses its flight activity over turf areas rather than windbreaks and spent compost piles, possibly for mating purposes. Our study found no evidence of M. halterata breeding in turf areas surrounding mushroom growing houses. In addition, flight activity is highest in the afternoon until midnight at higher temperatures, yet at lower temperatures activity ceases after sunset. Establishing temperature and daylight thresholds for M. halterata flight activity may be useful in developing integrated pest management ( IPM ) tactics for this species. The most successful IPM tool that mushroom growers use at present is fly exclusion. Exclusion can be improved by focusing farm operations around temperature and daylight thresholds when fly activity is at its lowest.

Video-recordings were made of adult spotted lanternflies, Lycorma delicatula, taking flight from apple trees in an orchard in northeast Pennsylvania in September, 2017 during a mass dispersal flight event involving thousands of adults. The trajectories of adults flying upwind in straight and level or gradually descending flight allowed them to traverse only up to ca. 40 m in a single flight-bout. Many did not make it to trees or bushes that were at even shorter distances than this and they landed in the grass. Flight tracks of 162 adults launching themselves into the wind from the upper branches of apple trees were video-recorded in plan view from below by a camera placed on the ground aimed straight up at the sky. The tracks were then digitized and analyzed using a triangle of velocities technique to determine the degree to which the adults were progressing in a directly upwind flight track, with the wind vector experienced by each adult calculated from the adults’ flight track itself. Average airspeeds of upwind-flying L. delicatula had been previously measured in another group of adults and shown to not vary with wind speed. The headings (direction of thrust) of adults in the video frames were determined by matching the image of the adult in each video frame with a template image of a pinned adult of a known distance from the camera and heading. Matching the body axis in this way works for this species because the adults flying in these elongated fairly straight flight paths did so with forewings spread out flat to the ground with little discernable roll. Having determined airspeed and heading plus ground speed and track for each set of images allowed the third side of the triangle of velocities — the wind velocity vector — to be calculated for each flying adult at whatever altitude or lateral location in the camera’s field of view it was flying. Adult L. delicatula were found to head upwind in flight at 10.7° off the wind line to produce resulting track angles of progression over the ground averaging 30.9° off the wind line due to this discrepancy between their headings and the wind velocities into which they were flying. The wind velocity vectors provided by a ground-based anemometer during the periods each adult was flying through the video frames deviated from the wind velocity vectors calculated using the triangle of velocities technique by nearly 22° and were 50% lower in wind speed than the calculated vectors taken at the higher altitudes and locations each adult was flying. The triangle of velocities technique might provide a new way of using certain species of insects as free-flying anemometers to take wind velocity readings at different heights and spatial locations that are not attainable through the use of ground-based anemometers.

We performed single-sensillum recordings from male and female antennae of the Asian longhorned beetle, Anoplophora glabripennis , that included as stimuli the two components of this species’ aggregation-sex pheromone in addition to various general odorants. We compared the aggregation-sex-pheromone-component responses of olfactory sensory neurons (OSNs) to those of OSNs that responded to a variety of plant-related odorants. In the smooth-tipped, tapered, trichoid sensilla on the most distal antennal flagellomeres nos. 10 or 11 of both males and females, we found OSNs with high-amplitude action potentials that were tuned to the aldehyde and alcohol pheromone components and that did not respond to various plant-related volatiles. Because this OSN type responded to both the alcohol and aldehyde components it cannot be considered to be specifically tuned to either component. These large-spiking OSNs were co-compartmentalized in these sensilla with a second, smaller-spiking OSN responding to plant-related volatiles such as geraniol, citronellal, limonene, 1-octanol, nerol and citral. The large-spiking OSNs thus appear to be a type that will be involved in aggregation-sex pheromone pathways targeting a specific glomerulus in the antennal lobe and in generating pheromone-related behavioral responses in A. glabripennis . In other sensilla located in these distal antennal flagellomeres as well as those located more proximally, i.e., mid-length along the antenna on flagellomere nos. 4–7, we found OSNs in blunt-tipped basiconic sensilla that were responsive to other plant-related volatiles, especially the terpenoids, ( E,E )-alpha farnesene, ( E )-β-farnesene, β-caryophyllene, and eugenol. Some of these terpenoids have been implicated in improving attraction to pheromone-baited traps. Some of these same OSNs responded additionally to either of the two sex pheromone components, but because these OSNs also responded to some of the above plant volatiles as shown by cross-adaptation experiments, these OSNs will not be the types that convey sex-pheromone-specific information to the antennal lobe.

Gas-chromatography-electroantennographic detection (GC-EAD) is a technique used in the identification of volatile organic compounds (VOCs), such as pheromones and plant host odors, which are physiologically relevant to insects. Although pheromones often elicit large EAD responses, other behaviorally relevant odors may elicit responses that are difficult to discern from noise. Lock-in amplification has long been used to reduce noise in a wide range of applications. Its utility when incorporated with GC-EAD was demonstrated previosuly by chopping (or pulsing) effluent-laden air that flowed over an insect antenna. This method had the disadvantage that it stimulated noise-inducing mechanoreceptors and, in some cases, disturbed the electrochemical interfaces in a preparation, limiting its performance. Here, the chopping function necessary for lock-in amplification was implemented directly on the GC effluent using a simple Deans switch. The technique was applied to excised antennae from female Heliothis virescens responding to phenethyl alcohol, a common VOC emitted by plants. Phenethyl alcohol was always visible and quantifiable on the flame ionization detector (FID) chromatogram, allowing the timing and amount of stimulus delivered to the antennal preparation to be measured. In our new chopper EAG configuration, the antennal preparation was shielded from air currents in the room, further reducing noise. A dose-response model in combination with a Markov-chain monte-carlo (MCMC) method for Bayesian inference was used to estimate and compare performance in terms of error rates involved in the detection of insect responses to GC peaks visible on an FID detector. Our experiments showed that the predicted single-trial phenethyl alcohol detection limit on female H. virescens antennae (at a 5.0% expected error rate) was 140,330 pg using traditional EAG recording methods, compared to 2.6–6.3 pg (5th to the 95th percentile) using Deans switch-enabled lock-in amplification, corresponding to a 10.4–12.7 dB increase in signal-to-noise ratio.

Flight is the most common form of locomotion used by insects to locate distant sources of sex pheromone. Although sex pheromone-mediated flight occurs in the vast majority of insect orders, by far the group most intensity observed and recorded for the purpose of understanding flight behavior is the Lepidoptera. This chapter focuses on studies of the flight behavior of male moths. The behavioral analysis of lepidopteran pheromone-mediated flight has always been performed with the goal of moving beyond merely counting the number of moths trapped at a source of pheromone and understanding what male moths do, how they maneuver in response to their pheromone. The chapter attempts to cover what has been learned about pheromone-mediated flight in moths from all levels of studies, but emphasizing what we know about the in-flight maneuvers that affect the moths' immediate complex problem of maintaining contact with the pheromone plume and advancing up it while tracking the wind direction.

The Asian longhorned beetle Anoplophora glabripennis (Motchulsky) is an exotic forest pest that has repeatedly invaded North America and Europe from Asia, and has the potential to kill millions of trees and cause billions of dollars in damage. Traps baited with an attractive mixture of volatile organic compounds from hosts have been of limited success in monitoring invasion sites. We propose that lures might be improved through studying the olfactory system of adult beetles, especially the gene family of odorant receptors (ORs) and the structure of the antennal lobes of the brain. Here, we report identification of 132 ORs in the genome of A. glabripennis (inclusive of one Orco gene and 11 pseudogenes), some of which are orthologous to known pheromone receptors of other cerambycid beetles. We also identified three ORs that are strongly biased toward expression in the female transcriptome, and a single OR strongly biased toward males. Three-dimensional reconstruction of the antennal lobes of adults suggested a male-specific macroglomerulus and several enlarged glomeruli in females. We predict that functional characterization of ORs and glomeruli will lead to identification of key odorants in the life history of A. glabripennis that may aid in monitoring and controlling future invasions.