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.