Male Crickets Research Articles

Testing the Effects of DL-Alpha-Tocopherol Supplementation on Oxidative Damage, Total Antioxidant Protection and the Sex-Specific Responses of Reproductive Effort and Lifespan to Dietary Manipulation in Australian Field Crickets (Teleogryllus commodus).

The oxidative stress theory predicts that the accumulation of oxidative damage causes aging. More generally, oxidative damage could be a cost of reproduction that reduces survival. Both of these hypotheses have mixed empirical support. To better understand the life-history consequences of oxidative damage, we fed male and female Australian field crickets (Teleogryllus commodus) four diets differing in their protein and carbohydrate content, which have sex-specific effects on reproductive effort and lifespan. We supplemented half of these crickets with the vitamin E isoform dl-alpha-tocopherol and measured the effects of nutrient intake on lifespan, reproduction, oxidative damage and antioxidant protection. We found a clear trade-off between reproductive effort and lifespan in females but not in males. In direct contrast to the oxidative stress theory, crickets fed diets that improved their lifespan had high levels of oxidative damage to proteins. Supplementation with dl-alpha-tocopherol did not significantly improve lifespan or reproductive effort. However, males fed diets that increased their reproductive investment experienced high oxidative damage to proteins. While this suggests that male reproductive effort could elevate oxidative damage, this was not associated with reduced male survival. Overall, these results provide little evidence that oxidative damage plays a central role in mediating life-history trade-offs in T. commodus.

Behaviour, metabolism and size: phenotypic modularity or integration in Acheta domesticus?

The pace-of-life hypothesis predicts that among-individual differences in behaviour should integrate with a wide variety of morphological, metabolic and life-history traits along a slow to fast pace-of-life continuum. Support for the pace-of-life hypothesis has been mixed, in part because most empirical tests have been conducted strictly at the phenotypic level and have thus conflated genetic and environmental sources of covariance among traits. In the present study, we tested the hypothesis that, according to the predictions of the pace-of-life hypothesis, body mass, routine metabolic rate, activity and exploratory propensity are positively integrated in the house cricket Acheta domesticus (Orthoptera: Gryllidae). Using modified open field behavioural tests and flow-through respirometry, we determined whether among-individual differences are correlated across morphology, behaviour and metabolism in 50 male house crickets. All traits were repeatable, but we found poor evidence for overall integration across traits. Instead we found evidence for modularity, with behavioural traits covarying independently from mass and routine metabolic rate. Modularity, like that found here between activity and exploratory propensity, has been suggested to facilitate adaptive evolutionary change by coupling functionally related traits into suites on which selection can act more rapidly.

Which Extrinsic and Intrinsic Factors are Associated with Non-Contact Injuries in Adult Cricket Fast Bowlers?

The high prevalence of injury amongst cricket fast bowlers exposes a great need for research into the risk factors associated with injury. Both extrinsic (environment-related) and intrinsic (person-related) risk factors are likely to be implicated within the high prevalence of non-contact injury amongst fast bowlers in cricket. Identifying and defining the relative importance of these risk factors is necessary in order to optimize injury prevention efforts. The objective of this review was to assess and summarize the scientific literature related to the extrinsic and intrinsic factors associated with non-contact injury inherent to adult cricket fast bowlers. A systematic review was performed in compliance with the PRISMA guidelines. This review considered both experimental and epidemiological study designs. Studies that included male cricket fast bowlers aged 18 years or above, from all levels of play, evaluating the association between extrinsic/intrinsic factors and injury in fast bowlers were considered for inclusion. The three-step search strategy aimed at finding both published and unpublished studies from all languages. The searched databases included MEDLINE via PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Cochrane Controlled Trials Register in the Cochrane Library, Physiotherapy Evidence Database (PEDro), ProQuest 5000 International, ProQuest Health and Medical Complete, EBSCO MegaFile Premier, Science Direct, SPORTDiscus with Full Text and SCOPUS (prior to 28 April 2015). Initial keywords used were 'cricket', 'pace', 'fast', 'bowler', and 'injury'. Papers which fitted the inclusion criteria were assessed by two independent reviewers for methodological validity prior to inclusion in the review using standardized critical appraisal instruments from the Joanna Briggs Institute Meta Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI). A total of 16 studies were determined to be suitable for inclusion in this systematic review. The mean critical appraisal score of the papers included in this study was 6.88 (SD 1.15) out of a maximum of 9. The following factors were found to be associated with injury: bowling shoulder internal rotation strength deficit, compromised dynamic balance and lumbar proprioception (joint position sense), the appearance of lumbar posterior element bone stress, degeneration of the lumbar disc on magnetic resonance imaging (MRI), and previous injury. Conflicting results were found for the association of quadratus lumborum (QL) muscle asymmetry with injury. Technique-related factors associated with injury included shoulder-pelvis flexion-extension angle, shoulder counter-rotation, knee angle, and the proportion of side-flexion during bowling. Bowling workload was the only extrinsic factor associated with injury in adult cricket fast bowlers. A high bowling workload (particularly if it represented a sudden upgrade from a lower workload) increased the subsequent risk to sustaining an injury 1, 3 or 4 weeks later. Identifying the factors associated with injury is a crucial step which should precede the development of, and research into, the effectiveness of injury prevention programs. Once identified, risk factors may be included in pre-participation screening tools and injury prevention programs, and may also be incorporated in future research projects. Overall, the current review highlights the clear lack of research on factors associated with non-contact injury, specifically in adult cricket fast bowlers. Johanna Briggs Institute Database of Systematic Reviews and Implementation Reports 1387 (Olivier et al., JBI Database Syst Rev Implement Rep 13(1):3-13. doi: 10.11124/jbisrir-2015-1387 , 2015).

Response of the insect immune system to three different immune challenges

Insects rely on an innate immune system to effectively respond to pathogenic challenges. Most studies on the insect immune system describe changes in only one or two immune parameters following a single immune challenge. In addition, a variety of insect models, often at different developmental stages, have been used, making it difficult to compare results across studies. In this study, we used adult male Acheta domesticus crickets to characterize the response of the insect innate immune system to three different immune challenges: injection of bacterial lipopolysaccharides (LPS); injection of live Serratia marcescens bacteria; or insertion of a nylon filament into the abdomen. For each challenge, we measured and compared hemolymph phenoloxidase (PO) and lysozyme-like enzyme activities; the number of circulating hemocytes; and the nodulation responses of challenged and un-challenged crickets. We found that injection of an LD50 dose of LPS from Escherichia coli elicited a more rapid response than an LD50 dose of LPS from S. marcescens. LPS injection could cause a rapid decrease 2hpi, followed by an increase by 7dpi, in the number of circulating hemocytes. In contrast, injection of live S. marcescens produced a rapid increase and then decrease in hemocyte number. This was followed by an increase in the number of hemocytes at 7dpi, similar to that observed following LPS injection. Both LPS and live bacteria decreased hemolymph PO activity, but the timing of this effect was dependent on the challenge. Live bacteria, but not LPS, induced an increase in lysozyme-like activity in the hemolymph. Insertion of a nylon filament induced a decrease in hemolymph PO activity 2h after insertion of the filament, but had no effect on hemocyte number or lytic activity. Our results indicate that the innate immune system’s response to each type of challenge can vary greatly in both magnitude and timing, so it is important to assess multiple parameters at multiple time points in order to obtain a comprehensive view of such responses.

Redescription of Argizala brasiliensis Walker, 1869 (Orthoptera: Grylloidea: Trigonidiidae: Nemobiinae: Pteronemobiini) and consideration of its morphological proximity to other Pteronemobiini Nearctic genera.

Although male crickets provide more informative characters for the delimitation of species and genera, many taxonomic descriptions are based only on females. This is the case for Argizala Walker, 1869 and its two valid species, A. brasiliensis Walker, 1869 and A. hebardi Rehn, 1915. We provide herein a redescription of A. brasiliensis based on a male collected in the Pampa Biome, Capão do Leão municipality, Rio Grande do Sul State, Brazil. We present photographs of epitype and male genitalia, and discuss the diagnostic features of the genus and its morphological proximity to other Pteronemobiini Nearctic genera.

Effect of immune challenge on aggressive behaviour: how to fight two battles at once

Animals are attacked by pathogens, predators and competitors, sometimes simultaneously. For example, male crickets fight each other for access to females and such challenges may occur when one or both males are also defending themselves against a pathogen. We tested whether males altered their aggressive motivation when faced with both a competitor and a pathogen simultaneously. We found that immune-challenged male crickets (Gryllus texensis) were more likely to defeat male competitors when the reproductive payoff (i.e. a female) was nearby. However, when females were not present, males showed a decrease in their aggressive behaviour, and were less likely to win encounters with control males. This plasticity of aggressive motivation did not occur when males were chronically immune challenged. Chronically immune-challenged males were more likely to be defeated by control males regardless of the presence of a female. These results suggest that the costs associated with a chronic immune challenge may prevent terminal reproductive investment. We show that males can benefit from terminal reproductive investment because acutely immune-challenged males were still capable of mating and females did not appear to discriminate against them. Male crickets appear to engage in a context-dependent trade-off between the ability to defeat pathogens and the ability to defeat competitors. This trade-off is mediated, in part, by changes in male aggressive motivation (i.e. the critical threshold for the decision to flee).

Calling Behavior of Male Acheta domesticus Crickets Infected with Paragordius varius (Nematomorpha: Gordiida).

It is well established that parasites in the phylum Nematomorpha induce suicide behavior of their insect hosts to bring adult worms to the appropriate habitat for emergence. It is not well established, however, whether other nematomorph-induced behavioral alterations occur before worm emergence. The purpose of our study was to evaluate the effect of the nematomorph Paragordius varius on the calling behavior of the male house cricket Acheta domesticus . We hypothesized that cricket calling, an energetically expensive and risky behavior, would be a potential target for nematomorph-induced behavioral alterations. We assessed if and how infection with P. varius affects A. domesticus calling behavior and whether the presence of wings at time of exposure to P. varius influenced changes in calling behavior. We recorded the calling behavior of male A. domesticus over the course of their infection after exposure to P. various before or after wing development. Additionally, we assessed whether winged crickets were "callers" or "noncallers" before exposure. We found that regardless of cricket developmental stage (or age) at time of infection, infected crickets spent significantly less time calling than their uninfected counterparts but only during the later stages of infection. Developmental stage at infection did affect whether crickets became callers: when infected before wing development significantly more uninfected crickets initiated calling; there was no difference between infected and uninfected crickets when infected as winged adults. Infection was a factor in whether callers stopped calling, with more infected crickets ceasing to call than uninfected crickets. This is the first study to show that infection with nematomorphs affects calling behavior of their insect host. Cricket calling behavior is immensely complex and although it was difficult to elucidate the adaptive nature of these parasite-induced behavioral changes, this study lays the groundwork for future studies to begin teasing out the factors that will help make the determination between side effect of infection or parasite/host adaptation.

The Use of Negative Pressure Wave Treatment in Athlete Recovery

Lower body negative pressure (LBNP) treatment was developed for astronauts in order to maintain the arterial blood supply of the lower body and compensate for weightlessness. In clinical applications the use of negative pressure has proven substantial in treatment of general soft-tissue injuries, open fractures, and management of diabetic and pressure ulcers. In competitive sport, regeneration and recovery of athletes play a vital role to maximise their performance. PURPOSE: Validation of the LBNP device by assessing if intermittent negative pressure therapy applied to the lower body of athletes has a systemic effect resulting in faster recovery time. METHODS: A random designed cross-over study with repeated measures was performed. Healthy male cricket players (n=22), aged 18-22 years continued to follow their weekly regular physical training program (7 hours conditioning and 10 hours cricket specific skills, with one competitive match on weekends), for the duration of the study. Additionally they were subjected to an intense and structured 1 hour exercise training program and power gym session on the day treatment started. Players were exposed to one 30 minute LBNP treatment session for three consecutive days (i.e. at 0, 24 and 48 hours). Heart rate, blood pressure, blood serum lactate and -creatine kinase (CK) were measured. RESULTS: During treatment sessions the heart rate and blood pressure decreased drastically but reverted back to baseline levels within an hour. Using the repeated measures ANOVA test, the lactate concentration did not show an individual (p=0.41) nor a period effect (p=0.11). In the group effect the lactate decreased significantly (p=0.008) after termination of exercise. The ratio of the period directly after training vs. the period directly after treatment was analysed. The LBNP device resulted in lowering lactate measurements significantly (control group 0.868; treatment group 0.575). ANOVA analysis of CK did not indicate a significant decrease after 3 treatment sessions. The CK concentration ratio after the third therapy session vs. after the first therapy session did not significantly decrease. CONCLUSION: LBNP therapy seems to have a systemic effect in lowering serum lactate levels, but not CK levels. Enhanced regeneration and recovery of athletes are still unconfirmed.

Releasing stimuli and aggression in crickets: octopamine promotes escalation and maintenance but not initiation

Biogenic amines have widespread effects on numerous behaviors, but their natural functions are often unclear. We investigated the role of octopamine (OA), the invertebrate analog of noradrenaline, on initiation and maintenance of aggression in male crickets of different social status. The key-releasing stimulus for aggression is antennal fencing between males, a behavior occurring naturally on initial contact. We show that mechanical antennal stimulation (AS) alone is sufficient to initiate an aggressive response (mandible threat display). The efficacy of AS as an aggression releasing stimulus was augmented in winners of a previous fight, but unaffected in losers. The efficacy of AS was not, however, influenced by OA receptor (OAR) agonists or antagonists, regardless of social status. Additional experiments indicate that the efficacy of AS is also not influenced by dopamine (DA) or serotonin (5HT). In addition to initiating an aggressive response, prior AS enhanced aggression exhibited in subsequent fights, whereby AS with a male antenna was now necessary, indicating a role for male contact pheromones. This priming effect of male-AS on subsequent aggression was dependent on OA since it was blocked by OAR-antagonists, and enhanced by OAR-agonists. Together our data reveal that neither OA, DA nor 5HT are required for initiating aggression in crickets, nor do these amines influence the efficacy of the natural releasing stimulus to initiate aggression. OA's natural function is restricted to promoting escalation and maintenance of aggression once initiated, and this can be invoked by numerous experiences, including prior contact with a male antenna as shown here.

Parallel effects of temperature on the male cricket calling song, phonotaxis of the female and the auditory responses of the L3 neurone

Sender–receiver coupling is a fundamental aspect of sexual communication systems, especially when the signal must travel over significant distances. In the cricket Acheta domesticus L., both the syllable period of the calling songs of males and the syllable periods that are most attractive to females are negatively correlated with temperature. However, the range of syllable periods that females respond to phonotactically extends beyond the range of males' calling songs at all temperatures tested. In habitats occupied by crickets, surface temperatures of the ground vary considerably. The cricket's body temperature changes rather quickly based on the amount of direct solar radiation encountered (7 °C in 1 min). The responses by females to calling songs with syllable periods outside of the males' range might be advantageous in countering the effects of local variations in temperature caused by variations in the microhabitat. A temperature shift in the response to syllable period of the L3 auditory neurone parallels the temperature shift seen in the phonotactic response over a similar temperature range. These similarities support the model of the involvement of L3 in the phonotactic response and its modulation by temperature.

Alternative Reproductive Tactics Arising from a Continuous Behavioral Trait: Callers versus Satellites in Field Crickets.

Alternative reproductive tactics may arise when natural enemies use sexual signals to locate the signaler. In field crickets, elevated costs to male calling due to acoustically orienting parasitoid flies create opportunity for an alternative tactic, satellite behavior, where noncalling males intercept females attracted to callers. Although the caller-satellite system in crickets that risk detection by parasitoids resembles distinct behavioral phenotypes, a male's propensity to behave as caller or satellite can be a continuously variable trait over several temporal scales, and an individual may pursue alternate tactics at different times. We modeled a caller-satellite-parasitoid system as a spatially explicit interaction among male and female crickets using individual-based simulation. Males varied in their propensity to call versus behave as a satellite from one night to the next. We varied mortality, density, sex ratio, and female mating behavior, and recorded lifetime number of mates as a function of a male's probability of calling (vs. acting as a satellite) along a gradient in parasitism risk. Frequently, the optimal behavior switched abruptly from being pure caller (call every night) to pure satellite (never call) as parasitism rate increased. However, mixed strategies prevailed even with high parasitism risk under conditions of higher background mortality rate, decreasing density, increasing female-biased sex ratio, and increasing female choosiness. In natural populations, high parasitoid pressure alone would be unlikely to yield fixation of pure satellite behavior.

Roaming Romeos: male crickets evolving in silence show increased locomotor behaviours

Loss of sexual signals should be strongly selected against when these signals are necessary for mate attraction or acquisition. Male Teleogryllus oceanicus field crickets produce a long-distance calling song to attract females. Separate genetic mutations recently evolved on the Hawaiian Islands of Kauai and Oahu, rendering approximately 90% and 50% of males, respectively, incapable of calling. We examined whether males from three populations, each with a distinct prevalence of this silent ‘flatwing’ phenotype, show behavioural plasticity in response to being reared in a call-less environment. Crickets from Kauai, Oahu and Mangaia, a Cook Islands population without the flatwing phenotype, either were or were not exposed to calling song during late juvenile and early adult development. Movement assays showed that when males originating from Kauai were reared in silence, they moved sooner, moved more and spent more time walking during silent behaviour trials than did their counterparts reared with calling song. Males from Oahu and Mangaia, however, showed no such effect of acoustic rearing environment on these behaviours. This suggests that there has been directional selection on Kauai for males to respond to a silent environment by increasing their mobility, thus compensating for their lack of song and increasing their chance of encountering receptive females.

The Sporting Lives of Sir Shenton Thomas and the Male European Internees at Changi Prison Camp During the Japanese Occupation of Singapore, 1942–1945

During the Japanese occupation of British Malaya and Southeast Asia from the years 1942 to 1945 there were reports of POWs being allowed to play cricket, football, rugby and basketball, as told by Kevin Blackburn in The Sportsmen of Changi published in 2012. This research about the sporting lives of a Governor and male European internees at Singapore's Changi prison is likely to be first detailed research on this topic. The authors depended mainly on four published diaries and 262 issues of the men's camp newspaper, Changi Guardian, to account for the male internees' casual and competitive cricket, football, hockey, volleyball, badminton, tennis and boxing matches that were played during internment. The Japanese Military Administration allowed the male internees to organize their daily lives and play games that they indulged in during the pre-War period as the British dominated the Singapore Cricket Club, Penang Cricket Club and Perak Club. The internees were able to play the various games and matches in spite of the limited food and sparse facilities. Many of the cricket and football games that were played were organized as inter-state, inter-club or league matches. These games were played with improvized equipment and rules.

Prior mating success can affect allocation towards future sexual signaling in crickets.

Fitness is often correlated with the expression level of a sexually selected trait. However, sexually selected traits are costly to express such that investment in their expression should be optimised to maximize their overall fitness gains. Social interactions, in the form of successful and unsuccessful matings, may offer males one type of feedback allowing them to gauge how to allocate their resources towards sexual signaling. Here we tested whether adult male black field crickets (Teleogryllus commodus) modify the extent of their calling effort (the sexually selected trait) in response to successful and unsuccessful matings with females. To examine the effect that mating interactions with females have on investment into sexual signaling, we monitored male calling effort after maturation and then provided males with a female at two points within their life, manipulating whether or not males were able to successfully mate each time. Our results demonstrate that males alter their investment towards sexual signaling in response to successful matings, but only if the experience occurs early in their life. Males that mated early decreased their calling effort sooner than males that were denied a mating. Our results demonstrate that social feedback in the form of successful and unsuccessful matings has the potential to alter the effort a male places towards sexual signaling.

On inheritance of calling song characteristics in the cricket Gryllus bimaculatus

Singing crickets are an appropriate object for analyzing genetic aspects of acoustic communication in insects. The calling song (CS) of male crickets, specifically, Gryllus bimaculatus, is a sequence of chirps consisting of 3–5 pulses. The average values of parameters used by females to identify conspecific males—pulse repetition period, number of pulses per chirp, chirp repetition period—are different for various geographic populations of crickets. In particular, populations of Gryllus bimaculatus from the south-eastern part of its distribution area, as compared to the Mediterranean population, are characterized by a longer chirp repetition period, greater number of pulses per chirp and shorter pulse repetition period [1]. These differences are genetically determined because they are retained in laboratory colonies of these populations under controlled conditions. In the present work, the rules of inheritance of the calling song parameters in interpopulation hybrids of crickets Gryllus bimaculatus were investigated. Two laboratory cultures of these crickets were used: of South Asian origin (A) descending, presumably, from Indo-China, and of Israeli origin (I). Both cultures have been cultivated for several years at Sechenov Institute of Evolutionary Physiology and Biochemistry. The calling songs of

Condition dependence of female choosiness in a field cricket.

Females generally choose mates that produce the loudest, brightest or most elaborate sexual displays, and these costly male displays are predicted to be condition dependent. However, mate choice itself is a costly behaviour also expected to be condition dependent. Male fall field crickets, Gryllus pennsylvanicus, produce a conspicuous long-distance calling song that attracts females and is condition dependent. In this study, we tested the condition dependence of female preferences (preference function and choosiness) for male calling effort in G.pennsylvanicus. We manipulated female condition by raising crickets from hatching on either a low- or high-quality diet. In a series of two-speaker phonotaxis trials, both low- and high-condition females preferred playbacks reflecting greater calling effort. However, relative to low-condition females, high-condition females took significantly longer to make a choice, were more likely to fail to choose within the time allotted for a phonotaxis trial and significantly increased their latency to choose over the course of multiple trials. We discuss these results with respect to the possibility that female G.pennsylvanicus may be foraging for direct benefits when they choose their mates.

A Comparative Study of Sports Competition Anxiety Test between College Level Chess and Cricket Players

The purpose of this study was to compare the sports competition anxiety test between college level chess and cricket players. For the purpose of the study, forty (40) male chess players and forty (40) male cricket players were randomly selected as the subject for this study. The subject age was ranged between 20 to 25 years. In this study sports competition anxiety test (SCAT, Martens et al., 1990) questionnaire was used to measure sports competition anxiety. Sports competition anxiety test questionnaire was distributed between the chess and cricket players one hour before the competition. The hypothesis selected for this study that there would be no significant difference between the chess and cricket players. Descriptive statistics (mean and standard deviation) and independent‘t’ test were used to analysis the data. The level of significance was set at 0.05. The mean score chess players was 19.20 and cricket players was 22.60. The calculated‘t’ value was 3.95 which showed that significant difference was found between chess players and cricket players (calculated‘t’ 3.95 > tabulated‘t’ 1.99).

Replicated evolutionary divergence in the cuticular hydrocarbon profile of male crickets associated with the loss of song in the Hawaiian archipelago.

Female choice based on male secondary sexual traits is well documented, although the extent to which this selection can drive an evolutionary divergence in male traits among populations is less clear. Male field crickets Teleogryllus oceanicus attract females using a calling song and once contacted switch to courtship song to persuade them to mate. These crickets also secrete onto their cuticle a cocktail of long-chained fatty acids or cuticular hydrocarbons (CHCs). Females choose among potential mates based on the structure of male acoustic signals and on the composition of male CHC profiles. Here, we utilize two naturally occurring mutations that have arisen independently on two Hawaiian islands and render the male silent to ask whether the evolutionary loss of acoustic signalling can drive an evolutionary divergence in the alternative signalling modality, male CHC profiles. QST -FST comparisons revealed strong patterns of CHC divergence among three populations of crickets on the islands of Hawaii, Oahu and Kauai. Contrasts between wild-type and flatwing males on the islands of Oahu and Kauai indicated that variation in male CHC profiles within populations is associated with the loss of acoustic signalling; flatwing males had a relatively low abundance of long-chained CHCs relative to the short-chained CHCs that females find attractive. Given their dual functions in desiccation resistance and sexual signalling, insect CHCs may be particularly important traits for reproductive isolation and ultimately speciation.

Visual display in Blanchard's cricket frogs (Acris blanchardi)

Abstract Most reports of anuran visual displays (especially those involving extension of the back legs) are of tropical species living within noisy habitats. Here, we provide a descriptive report of visual displays involving back leg extension in a temperate anuran, Blanchard's cricket frog (Acris blanchardi). We observed male cricket frogs engaging in bouts of display, lasting an average of 2.9 min and incorporating both visual and acoustic signals. In a typical display bout, frogs near each other began circling (during a chorus at the pond) within a small area while extending their back legs and occasionally vocalizing. Rarely, the frogs would attack one another by hopping onto, then off, an opponent. Bouts ended when individuals stopped displaying while remaining near each other. The most common behaviors observed during a display bout, in order of decreasing frequency, were leg extensions, direction changes, forward movements, and vocalizations. These observations increase prospects for the study of e...

Sex-specific interactions of microbial symbioses on cricket dietary selection.

The nutrients found in prey and nonprey foods, and relative digestibility of these foods, has a major influence on diet selection by omnivorous insects. Many insects have developed symbiotic relationships with gut bacteria to help with extracting nutrition from nonprey diets. Gryllus pennsylvanicus (Burmeister) (Orthoptera: Gryllidae) was assigned to one of two treatment groups, antibiotic-treated and nonantibiotic-treated, and consumption of seeds (nonprey) and eggs (prey) were measured. Male crickets administered antibiotics consumed more seeds and greater seed weight, while antibiotic-fed female crickets consumed fewer seeds and less seed weight, relative to the untreated male and female crickets, respectively. Both male and female antibiotic-treated crickets consumed similar weight of eggs as nonantibiotic-treated male and female crickets, respectively. These results provide evidence that gut symbionts influence diet selection of male and female G. pennsylvanicus differently. This sex-specific dietary selection may be because of the fact that male and female crickets have different nutritional requirements.