Contact Chemoreceptors Research Articles

Harmful and Harmless Soil-Dwelling Fungi Indicate Microhabitat Suitability for Off-Host Ixodid Ticks.

Following blood meals or questing bouts, hard ticks (Ixodidae) must locate moist off-host microhabitats as refuge. Soil-dwelling fungi, including entomopathogenic Beauveria bassiana (Bb), thrive in moist microhabitats. Working with six species of ixodid ticks in olfactometer bioassays, we tested the hypothesis that ticks avoid Bb. Contrary to our prediction, nearly all ticks sought, rather than avoided, Bb-inoculated substrates. In further bioassays with female black-legged ticks, Ixodes scapularis, ticks oriented towards both harmful Bb and harmless soil-dwelling fungi, implying that fungi-regardless of their pathogenicity-signal habitat suitability to ticks. Only accessible Bb-inoculated substrate appealed to ticks, indicating that they sense Bb or its metabolites by contact chemoreception. Bb-inoculated substrate required ≥24 h of incubation before it appealed to ticks, suggesting that they respond to Bb metabolites rather than to Bb itself. Similarly, ticks responded to Bb-inoculated and incubated cellulose but not to sterile cellulose, indicating that Bb detection by ticks hinges on the Bb metabolism of cellulose. 2-Methylisoborneol-a common fungal metabolite with elevated presence in disturbed soils-strongly deterred ticks. Off-host ticks that avoid disturbed soil may lower their risk of physical injury. Synthetic 2-methylisoborneol could become a commercial tick repellent, provided its repellency extends to ticks in diverse taxa.

Evidence for tactile 3D shape discrimination by octopus.

Octopuses integrate visual, chemical and tactile sensory information while foraging and feeding in complex marine habitats. The respective roles of these modes are of interest ecologically, neurobiologically, and for development of engineered soft robotic arms. While vision guides their foraging path, benthic octopuses primarily search "blindly" with their arms to find visually hidden prey amidst rocks, crevices and coral heads. Each octopus arm is lined with hundreds of suckers that possess a combination of chemo- and mechanoreceptors to distinguish prey. Contact chemoreception has been demonstrated in lab tests, but mechanotactile sensing is less well characterized. We designed a non-invasive live animal behavioral assay that isolated mechanosensory capabilities of Octopus bimaculoides arms and suckers to discriminate among five resin 3D-printed prey and non-prey shapes (all with identical chemical signatures). Each shape was introduced inside a rock dome and was only accessible to the octopus' arms. Octopuses' responses were variable. Young octopuses discriminated the crab prey shape from the control, whereas older octopuses did not. These experiments suggest that mechanotactile sensing of 3D shapes may aid in prey discrimination; however, (i) chemo-tactile information may be prioritized over mechanotactile information in prey discrimination, and (ii) mechanosensory capability may decline with age.

Morphology and location of sensilla in the antennae and ovipositor of Sirex noctilio (Hymenoptera: Siricidae)

The woodwasp Sirex noctilio Fabricius is a major quarantine pest that was reported in China in 2013 and mostly damages Pinus sylvestris var. mongolica. Reverse chemical ecology, which uses chemical lures to catch or block insects from mating is the classic way to control forestry pests. This indicates that insect sensilla play a crucial role in detecting external chemical and physical stimuli. Nonetheless, the categorization and distribution of sensilla on the antennae and ovipositor of S. noctilio are insufficiently specific. In this paper, scanning electron microscopy (SEM) was used to observe the ultrastructure of the sensilla of S. noctilio on the antenna and ovipositor. It was found that the types and distribution of sensilla on the antennae of S. noctilio male and female are consistent, and six types of sensilla are found: sensilla trichodea (ST), sensilla chaetica (SC), Böhm bristles (BB), sensilla basiconica (SB), sensilla ampullacea (SA), and contact chemoreceptors (CC). Besides, there are five types of sensilla on the female ovipositor. In addition to ST, SC and BB, two more types of sensilla are also found: sensilla cavity (SCa) and sensilla coeloconica (SCo). Through identification of the morphology and distribution of the sensilla, the functions of different sensilla in the mating and host selection mechanisms of S. noctilio are proposed, thereby establishing a foundation for S. noctilio chemical communication research.

Contact chemoreception in multi-modal sensing of prey by Octopus.

Octopuses have keen vision and are generally considered visual predators, yet octopuses predominantly forage blindly in nature, inserting their arms into crevices to search and detect hidden prey. The extent to which octopuses discriminate prey using chemo- versus mechano-tactile sensing is unknown. We developed a whole-animal behavioral assay that takes advantage of octopuses' natural searching behavior to test their ability to discriminate prey from non-prey tastes solely via contact chemoreception. This methodology eliminated vision, mechano-tactile sensing and distance chemoreception while testing the contact chemosensory discriminatory abilities of the octopus arm suckers. Extracts from two types of prey (crab, shrimp) and three types of non-prey (sea star, algae, seawater) were embedded in agarose (to control for mechano-tactile discrimination) and presented to octopuses inside an artificial rock dome; octopuses reached their arms inside to explore its contents - imitating natural prey-searching behavior. Results revealed that octopuses are capable of discriminating between potential prey items using only contact chemoreception,as measured byan increased amount of sucker contact time and arm curls when presented with prey extracts versus non-prey extracts. These results highlight the importance of contact chemoreception in the multi-modal sensing involved in a complex foraging behavior.

Olfactory responses of Argentine stem weevil to herbivory and endophyte-colonisation in perennial ryegrass

Argentine stem weevil adults (ASW, Listronotus bonariensis) feed on the leaves of agricultural grasses and their larvae mine the pseudostem, causing extensive damage that can result in plant death. Plants emit volatiles that serve as signals to host-searching insects and these odours can be altered by both herbivory and fungal endophyte-infection. This study investigated whether ASW adults utilise olfaction to identify their host plants, perennial ryegrass (Lolium perenne), and if conspecific herbivory or the presence of Epichloë festucae var. lolii fungal endophytes (strain wild-type or AR1) influenced such responses. Results from olfactometer bioassays established that ASW adults were able to utilise their olfactory response to orient towards volatiles released by perennial ryegrass and further, the weevils displayed a preference for plants previously damaged by conspecific weevils. However, there was no evidence that weevils had the ability to distinguish between endophyte-infected and endophyte-free plants using olfaction alone. Using a push–pull extraction technique, thirteen volatile compounds were identified in the blend released by perennial ryegrass. Endophyte and herbivory were found to alter these volatile compounds and quantities emitted by this forage grass. This study suggests that despite observing differences in the plant volatile blend, ASW do not perceive endophyte (wild-type and AR1) using olfaction alone and must rely on other cues, e.g. contact chemoreception or post-ingestional malaise, to detect the presence of a bioactive endophyte in an otherwise acceptable host plant.

SCANNING ELECTRON MICROSCOPIC INVESTIGATING DIFFERENT TYPE OF SENSORY SENSILLAE ON THE HEAD APPENDAGES OF ASIAN TIGER MOSQUITO, AEDES ALBOPICTUS (SKUSE)

In Aedes albopictus various types of sensillae were on the head and its appendages with distinctmorphological features. The antennae and maxillary palps play a major role in host detection,and other sensory-mediated behaviors. Six long sensilla chaetica were arranged in circularshape and spread uniformly across the diameter of the antennal flagellomers. Maxillarypalp is a relatively simple organ compared to antennae, consists of five segments, which denselycovered dorsal side with flattened scales, but chemosensory sensilla on ventral side. Thus,a desirable model for exploring neuromolecular networks surrounds chemo- and mechanosensation.Proboscis analyses gustatory code via food intake and involved in identification. Labellumexhibits the most of sensory structures on the proboscis. Numerous sensillatrichoidea distributeon antennal flagellomers.A significant difference in diameter of sensillacoeloconica that protruding from distal tip ofantennal flagellomers. Sensillachaetica with greater morphological variation were distributedthroughout Ae. albopictus head and appendages. Variation between different sensillae indicatestheir functions. Aporous sensilla play the mechanoreceptive role but, porous sensillawere contact chemoreceptors and olfactory ones. sensory mechanisms were extensivestudied, about Asian tiger mosquito, Ae. albopictus sensory systems is insufficient.

Dorsal setae in Raoiella (Acari: Tenuipalpidae): Their functional morphology and implication in fluid secretion

The setae of mites are not regarded as secretory structures, yet in the flat mite genus Raoiella, each developmental stage presents droplets of fluid associated with the tips of their dorsal setae. To understand the origin of this fluid, the ultrastructure of the dorsal setae is investigated in females of Raoiella bauchani Beard & Ochoa and the invasive pest species Raoiella indica Hirst using scanning and transmission electron microscopy techniques.The dorsal setae are barbed along their entire length and have either a broadened plumose or a flat spatulate tip. Ultrastructurally, they present the typical features of mechanoreceptors, but have a “hollow” axis represented by a protoplasmatic core containing dendritic branches. This combination of ultrastructural characters indicates that the setae might be multimodal receptors: acting as both mechanoreceptors and contact chemoreceptors. The epidermal cells that underlie the setal sockets are columnar and have an ultrastructure that suggests they have a glandular function. Moreover, these cells present regular microvilli apically and form extracellular cuticular canals, containing epicuticular filaments, that are connected with the microvilli proximally and which open via pores onto the surface of the setal base distally. This arrangement indicates that the secretion from the microvilli passes into the canals and is then conducted to pores at the base of the seta, where it then accumulates and moves up the setal shaft, along the longitudinal grooves of the barbs. Based on similar arrangements in some insect taxa, the organization of the structures here observed in Raoiella suggests the passage of a non-polar, water insoluble, lipoid fluid through the cuticle, the function of which is still obscure.

Detection of conspecifics through olfaction in the Neotropical harvestman Mischonyx cuspidatus (Arachnida: Opiliones)

Chemoreception is a main sensory modality in harvestmen but there has been no experimental evidence of attraction to conspecifics by olfaction excluding contact chemoreception as an alternative explanation. Here, using a Y-maze olfactometer we tested whether the harvestman Mischonyx cuspidatus (Roewer, 1913) is attracted to volatiles of conspecifics. We found that males were attracted to volatiles of other males, but not females. Females were not attracted to female's volatiles, but were marginally more often attracted to volatiles of males. Our results help understanding mechanisms in mating and social behavior in the order Opiliones.

Neonicotinoids suppress contact chemoreception in a common farmland spider

Neonicotinoid insecticides are increasingly recognized for their role as information disruptors by modifying the chemical communication system of insects and therefore decreasing the chances of reproduction in target insects. However, data from spiders are lacking. In the present study, we tested the responses of males of a common agrobiont spider, Pardosa agrestis, to the application of field-realistic concentration of acetamiprid, which was formulated as Mospilan, and trace amounts of thiacloprid, which was formulated as Biscaya. We applied fresh or 24-h-old residues of Mospilan or Biscaya to the males just prior to the experiment or treated only the surface of a tunnel containing female draglines. We evaluated the ability of the males to recognize female cues from female dragline silk in a Y-maze. The field-realistic, sublethal doses of Mospilan altered pheromone-guided behavior. The choice of the tunnel with female draglines by males was hampered by tarsal treatment of the males with 24 h-old residues of Mospilan. The mating dance display was commonly initiated in control males that came into contact with female draglines and was suppressed by the Mospilan treatments in all three experimental settings. Some males only initiated the mating dance but did not manage to complete it; this was particularly true for males that were treated tarsally with fresh Mospilan residues, as none of these males managed to complete the mating dance. All three experimental settings with Mospilan decreased the frequency of males that managed to both select the tunnel with female draglines and complete the mating dance. The responses to the low-dose Biscaya were much milder and the study was not sufficiently powered to confirm the effects of Biscaya; however, the surprisingly observed trends in responses to very low Biscaya concentrations call for further analyses of long-term effects of trace amounts of neonicotinoids on the pheromone-guided behavior of spiders. These are the first conclusive data regarding the effects of commercially available formulations of neonicotinoid insecticides on the intraspecific chemical communication of spiders.

Self-derived chemical cues support home refuge recognition in the whip spider Phrynus marginemaculatus (Amblypygi: Phrynidae)

Whip spiders (Class Arachnida: Order Amblypygi) are hypothesized to use multimodal sensory inputs to navigate back to their diurnal shelter after a night of activity, and chemical cues are thought to be involved. In two experiments, we investigated whether self-deposited chemical cues on a substrate could be used for shelter recognition by Phrynus marginemaculatus C.L. Koch, 1840. When given a choice, individual P. marginemaculatus spent more time in a shelter that contained filter paper it had previously contacted compared to a shelter with filter paper never contacted. In the second experiment, subjects showed no significant preference for a shelter that contained filter paper they had contacted compared to a shelter with filter paper that had been contacted by a conspecific. The data support the hypothesis that during the last stage of nightly navigation to their refuge, detection of self-deposited chemical cues, likely mediated by contact chemoreceptors, may facilitate home refuge recognition by P. marginemaculatus.

Functional Analysis of the Chemosensory Protein GmolCSP8 From the Oriental Fruit Moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae).

Chemosensory proteins (CSPs) belong to a family of small water-soluble proteins that can selectively bind and transport odorant molecules for olfactory communication in insects. To date, their definite physiological functions in olfaction remain controversial when compared with odorant binding proteins (OBPs). To investigate the functions of CSPs in the oriental fruit moth Grapholita molesta, we determined the tissue expression patterns and binding properties of the CSP, GmolCSP8. The key binding sites of GmolCSP8 with a representative ligand were evaluated using molecular flexible docking, site-directed mutagenesis and ligand-binding experiments. Multiple sequence alignment and phylogenetic analysis showed that GmolCSP8 possesses a typical conserved four cysteines motif and shares high sequence identity with some CSP members of other Lepidopteran insects. GmolCSP8 was predominantly expressed in the wings and antennae of both male and female adults and may be involve in contact chemoreception. Recombinant GmolCSP8 (rGmolCSP8) exhibited specific-binding affinities to small aliphatic alcohols (C4–12) and had the strongest binding affinity to 1-hexanol. The three-dimensional structure of GmolCSP8 was constructed using the structure of sgCSP4 as a template. Site-directed mutagenesis and ligand-binding experiments confirmed that Thr27 is the key binding site in GmolCSP8 for 1-hexanol binding, because this residue can form hydrogen bond with the oxygen atom of the hydroxyl group in 1-hexanol, and Leu30 may play an important role in binding to 1-hexanol. We found that pH significantly affected the binding affinities of rGmolCSP8 to ligand, revealing that ligand-binding and -release by this protein is related to a pH-dependent conformational transition. Based on these results, we infer that GmolCSP8 may participate in the recognition and transportation of 1-hexanol and other small aliphatic alcohols.

Antennae and the role of olfaction and contact stimulation in mate recognition by males of the pollinating fig wasp Ceratosolen gravelyi (Hymenoptera: Agaonidae)

ABSTRACTFinding a mate is a crucial step in sexual reproduction. The mutualism between figs and their pollinators is exploited by many figwasps that develop within their galls and attain sexual maturity simultaneously. Male pollinators carry the specific burden of detecting and opening mating holes in galls containing conspecific females before mating with them. The mating behaviourand antennal sensilla of male pollinators associated with Ficus semicordata was investigated to understand mate recognition. Male Ceratosolen gravelyi located female-containing galls from a distance, but only attempted to chew a mating hole after antennal contact with the gall surface was made. They showed similar responses to females and body extracts but failed to respond to washed female bodies. This behaviour indicates that unidentified chemicals present on the body surfaces of females are sufficient to elicit olfactory attraction and tactile confirmation. Multiporous plate sensilla are candidates for olfactory reception from a distance while basiconic sensilla may be involved in contact chemoreceptor. All of the sensilla are highly localised, on the distal part of the terminal flagellomere, suggesting a response to selection for strong directionality in the complex odour environment of the fig in which messages produced by hundreds of females may confuse precise mate localisation.

Food recognition in hematophagous insects.

Hematophagous insects use heat, odors, visual cues and humidity emitted by vertebrate hosts to find them in space and time. Once they reach a host, they integrate multimodal information from its skin, and decide whether to bite or not. If skin conditions fulfil the insect's expectations, it bites and pumps a small quantity of blood. Again, only if the sampled blood fulfils the insect's feeding requirements, it continues with a full ingestion. Taste is involved in both timely linked evaluation processes via contact chemoreceptors located in different parts of their bodies, driving jointly food acceptance or rejection. However, the whole picture of how blood-sucking insects evaluate the quality of a potential host is poorly understood. Here, I summarize the actual knowledge about the feeding decision-making in blood-sucking insects. Being typically involved in the transmission of diseases to humans or livestock, a deeper understanding about factors affecting an essential process as feeding in these insects could help us to find new strategies to reduce interactions.

Scanning Electron Microscopy of the Antennal Sensilla and Their Secretion Analysis in Adults of Aromia bungii (Faldermann, 1835) (Coleoptera, Cerambycidae).

Background: It has been proved that chemical signals play an important role in mating location and reproductive behavior in cerambycids; moreover, they rely on contact chemoreception for mate recognition. Methods: Adult antennae of Aromia bungii were observed using scanning electron microscopy and adult antennal secretions were collected and analyzed with gas chromatography-mass spectrometry. Results: Twelve different types of sensilla were morphologically described on the antennae of A. bungii. At least six mechanoreceptors—one gustative, one putative chemo- or thermoreceptor, and three multiporous olfactory receptors—are present on the antennae of both sexes while a receptor-type of unclear function is limited to males. Secretions associated with sensilla basiconica were observed for the first time in a cerambycid species. Conclusions: Sensilla basiconica should play a role in odor perception detecting host tree volatiles and/or pheromones. Sensilla basiconica type 1 and 2 produce a viscous material accumulating on the antennal surface. Chemical analysis of adult antennal secretions highlighted marked differences between sexes. Some of the identified compounds have been previously reported as contact pheromone components of other cerambycid species. Our observations strongly suggest sensilla basiconica as the production sites of compounds involved in mate recognition.

Nocturnal navigation by whip spiders: antenniform legs mediate near-distance olfactory localization of a shelter

Navigation by terrestrial arthropods that wander away from a shelter in search of food or mates in uncluttered environments invariably relies on path integration mechanisms, which provide distance and direction information used to compute a straight-line return trajectory. Navigation in cluttered habitats is more typically visually guided, even in species that are nocturnal. Nocturnal, tropical arachnids in the order Amblypygi, however, depend neither on path integration nor on vision to navigate and are hypothesized to instead rely on highly sensitive olfactory structures. The distal articles of their antenniform legs are covered with receptors that presumably bind the odour stimuli thought to control, at least in part, their impressive ability to relocate a shelter after they wander in a rainforest understory. To test the hypothesis that olfactory inputs from the antenniform legs support their near-distance ability to localize a shelter, we conducted a laboratory experiment with the amblypygid Phrynus marginemaculatus in which an olfactory cue (with contact chemoreception precluded) identified the location of a shelter, the position of which was varied as subjects were trained. Localization of a shelter was readily learned and performance was fully retained over a 2-week period in which subjects were not trained. Localization of the odour-cued shelter declined markedly, however, when the distal articles of the antenniform legs were amputated. Moreover, the residual discrimination ability displayed by subjects when they were subsequently retrained depended on how many olfactory receptors had been removed. The results clearly demonstrate that odour cues can support near-distance goal localization and that receptors on the antenniform legs are the locus of the peripheral neural transduction necessary when odour is used to identify the position of a shelter.

Olfactory navigation in aquatic gastropods.

Gastropod diversity is substantial in marine and freshwater habitats, and many aquatic slugs and snails use olfactory cues to guide their navigation behaviour. Examples include finding prey or avoiding predators based on kairomones, or finding potential mates using pheromones. Here, I review the diversity of navigational behaviours studied across the major aquatic taxa of gastropods. I then synthesize evidence for the different theoretical navigation strategies the animals may use. It is likely that gastropods regularly use either chemotaxis or odour-gated rheotaxis (or both) during olfactory-based navigation. Finally, I collate the patchwork of research conducted on relevant proximate mechanisms that could produce navigation behaviours. Although the tractability of several gastropod species for neurophysiological experimentation has generated some valuable insight into how turning behaviour is triggered by contact chemoreception, there remain many substantial gaps in our understanding for how navigation relative to more distant odour sources is controlled in gastropods. These gaps include little information on the chemoreceptors and mechanoreceptors (for detecting flow) found in the peripheral nervous system and the central (or peripheral) processing circuits that integrate that sensory input. In contrast, past studies do provide information on motor neurons that control the effectors that produce crawling (both forward locomotion and turning). Thus, there is plenty of scope for further research on olfactory-based navigation, exploiting the tractability of gastropods for neuroethology to better understand how the nervous system processes chemosensory input to generate movement towards or away from distant odour sources.

LPS perception through taste-induced reflex in Drosophila melanogaster

In flies, grooming serves several purposes, including protection against pathogens and parasites. Previously, we found Escherichia coli or lipopolysaccharides (LPS) can induce grooming behavior via activation of contact chemoreceptors on Drosophila wing. This suggested that specific taste receptors may contribute to this detection. In this study, we examined the perception of commercially available LPS on Drosophila wing chemoreceptors in grooming reflex. Behavioral tests conducted with bitter, sweet and salty gustation such as caffeine, sucrose and salt, using flies carrying a defect in one of their taste receptors related to the detection of bitter molecules (Gr66a, Gr33a), sugars (Gr5a, Gr64f), or salt (IR76b). LPS and tastants of each category were applied to wing sensilla of these taste defectflies and to wild-type Canton Special (CS) flies. Our results indicate that the grooming reflex induced by LPS requires a wide range of gustatory genes, and the inactivation of any of tested genes expressing cells causes a significant reduction of the behavior. This suggests that, while the grooming reflex is strongly regulated by cues perceived as aversive, other sapid cues traditionally related to sweet and salty tastes are also contributing to this behavior.

Functional Characterization of the Gustatory Sensilla of Tarsi of the Female Polyphagous Moth Spodoptera littoralis.

Contact chemoreception is crucial for host plant choice selection in insects and is guided by input from gustatory receptor neurons, GRNs, housed in gustatory sensilla. In this study, the morphology and response spectra of individual tarsal sensilla on the fifth tarsomere of females of the moth Spodoptera littoralis were investigated. Two distinct morphological types of gustatory sensilla, TI and TII, were identified. Extracellular electrophysiological recordings were performed on each sensillum type using three sugars, two bitter substances and salt. Three distinct functional classes (TIα, TIβ, TII) were characterized, using cluster analysis based on the response spectra of three of the four responding GRNs. While each functional type of sensillum housed GRNs responding to salt, sugars and bitter compounds, the identity of these cells differed among the functional classes. Interestingly, an interaction between the GRNs responding to sugar and caffeine was found in both TIβ and TII sensilla, when binary mixtures were tested. This study provides a functional screening of the tarsal gustatory sensilla, showing a differentiation between sensilla on the tarsi of S. littoralis, providing the female moth with information that can facilitate host plant choice decisions.

Description of pereiopod setae of scyllarid lobsters, Scyllarides aequinoctialis, Scyllarides latus, and Scyllarides nodifer, with observations on the feeding during consumption of bivalves and gastropods

The morphological and behavioral aspects of slipper lobster (Scyllaridae) feeding have remained largely unexplored. Using scanning electron microscopy, the gross morphological structure of all segments of the pereiopods were described for three species of scyllarid lobsters. Five types of setae within three broad categories were found: simple (long and miniature), cuspidate (robust and conate), and teasel (a type of serrulate setae). Setae were arranged in a highly-organized, row-like pattern on the ventral and dorsal surfaces. Cuspidate setae were found on all surfaces of all segments. Simple setae were found only on the dactyl, whereas teazel setae were concentrated on the lateral-most edge of the alate carina on the merus in only one species [Scyllarides aequinoctialis (Lund, 1793)]; this species also differed from the other two [Scyllarides nodifer (Stimpson, 1866), Scyllarides latus (Latreille, 1803)] in setal patterning. All examined slipper lobsters differed in setal types and patterns from nephropid and palinurid lobsters, likely due to the more rigorous use of their pereiopods in accessing food. Feeding sequences of two of the slipper lobster species were videotaped and analyzed, and demonstrated a complex set of behaviors involving contact chemoreception by the antennules as part of an initial assessment of the food item, followed by extensive manipulation, probing, and eventual wedging behavior by the pereiopods as previously described for Scyllarides. Use of the antennules for food assessment and heavy reliance on the pereiopods, rather than the mouthparts, for food handling contrasts with nephropid and palinurid lobsters.

Behavioral responses of pest mole crickets, Neoscapteriscus spp. (Orthoptera: Gryllotalpidae), to selected insecticides

Mole crickets (Neoscapteriscus spp.) consume turfgrasses and pasture grasses and uproot plants by their tunneling, which is detrimental to turf aesthetics and decreases forage quantity and quality. Insecticides are frequently used to prevent damage. In typical field trials, damage symptoms, not percent mortality or achieved level of control, are used to assess treatment efficacy. Here, however, laboratory tests assessed the direct effect of key insecticides on Neoscapteriscus mole cricket behavior. Mole crickets, Neoscapteriscus spp., were able to detect and avoid areas treated with fipronil [formulated product (FP)] and imidacloprid (FP). They tunneled less in sand treated with fipronil and avoided sand treated with fipronil and imidacloprid if given a choice. Mole crickets escaped areas treated with acephate, bifenthrin and fipronil. Bifenthrin and acephate caused increased tunneling during the first 90 min of observation. Fipronil and imidacloprid significantly reduced overall tunneling on treated areas. Tested insecticides elicited two types of behavioral changes in Neoscapteriscus mole crickets: increased locomotory activity and tunneling [acephate (organophosphate) and bifenthrin (pyrethroid)] and reduced spatial movement [fipronil (phenylpyrazole) and imidacloprid (neonicotinoid)]. These behavioral responses resulted mainly from contact chemoreception and inherent neurotoxicity of the chemicals on Neoscapteriscus mole crickets. © 2017 Society of Chemical Industry.