N. Neveu et al., Host-stage selection by Trybliographa rapae, a parasitoid of the cabbage root fly Delia radicum, ENT EXP APP, 96(3), 2000, pp. 231-237
Host-stage selection by Trybliographa rapae Westwood (Hymenoptera: Figitida
e) was studied in choice and no-choice experiments in the laboratory. The p
arasitoid was able to reproduce in first, second, and third instars of the
cabbage root fly, Delia radicum L. (Diptera: Anthomyiidae), but oviposition
occurred more frequently in third instars when all three developmental sta
ges were offered simultaneously. Oviposition in third instars increased the
rate of development of offspring and their body size, but did not alter se
x ratio. Results are discussed in the light of predictions made by the theo
ry of optimal host acceptance.