Egg-laying behaviour following infection in the cricket<i>Gryllus texensis</i>

Abstract

To maximize fitness, the rate of offspring production should be sensitive to factors that predict the likelihood of parental survival. We predicted that acutely activating the immune system in the cricket Gryllus texensis Cade and Otte, 2000, signaling the possibility of decreased life expectancy, would lead to an immediate increase in reproductive effort. We found that lifetime fecundity varied among individual crickets and that female crickets laid more eggs in moist sand than in moist cotton, suggesting that females have the capacity to increase oviposition rates in response to substrate conditions. However, we found that exposing female crickets to a potentially lethal pathogen, Serratia marcescens Bizio, led to an increase in egg laying only when substrate conditions were preferable or at doses approaching the LD 50 .