Sandy beach dwelling crickets (Orthoptera: Trigonidiidae) have no preference for substrates that match their body color

Abstract

Habitat choice is an important behavior for maximizing fitness. One of the factors involved in habitat choice is preference for habitat substrates. In the context of predatory avoidance, it is adaptive to prefer substrates that are matched to own body color. The ground cricket Dianemobius csikii (Bolívar, 1901) occurs on sandy beaches. The body color of D. csikii resembles the sand of their habitat, which could be a form of crypsis. If D. csikii is not able to choose a suitable habitat background that matches their body color, the crickets incur a high risk of predation. The risk could result in population decline of the cricket. To examine whether D. csikii shows preference for substrates that match its body color, we undertook a two-choice test of sand or soil substrates after controlling the type of flooring substrates used during rearing. The crickets did not show preference for sand. There was no significant effect of flooring substrates during the nymph stage on the preference. These results suggest that when habitats are fragmented, crickets do not actively choose a cryptic background. There were significant differences in the substrate preference between sexes. These results reflect differences in the reproductive strategies of males and females.