The effect of competition between ovipositing females on their clutch size decisions is studied in parasitoid insects. The effect of this competition depends on whether the competition between parasitoid larvae within a host is contest (solitary parasitoids) or scramble competition (gregarious parasitoids). For gregarious parasitoids, a decreasing clutch size with increasing competition between females is predicted while for solitary parasitoids an increase is predicted. These predictions mere tested using the gregarious parasitoid Aphaereta minuta (M. E. Visser, 1996, Behav. Ecol. 7, 109-114) and the solitary parasitoid Comperiella bifasciata (J. A. Rosenheim and D. Hongkham, 1996, Anim. Behav. 51, 841-852). Parasitoids were either kept alone or in groups before the experiments, in which they were introduced singly into a patch containing unparasitized hosts. In the experiment with A. minuta, females kept together before the experiment laid smaller clutches than females kept alone. In C. bifasciata, the clutch size laid by females kept together was larger than that of females kept alone. Thus, both predictions were supported. [KEYWORDS: parasitoids; clutch size; competition; Aphaereta minuta; Comperiella bifasciata Hymenoptera; superparasitism; patch; oviposition; braconidae; allocation; females; wasp]
Original languageEnglish
JournalBiological Control
Journal publication date1998

ID: 296752