Resource Utilization Patterns in a Community of Gall-Attacking Parasitoids

Publisher Website
Google Scholar
Abstract
The natural history of the parasitoids attacking Asteromyia carbonifera (O.S.) (Diptera: Cecidomyiidae) was studied. Five species were recorded: Platygaster solidaginis (Ashmed)(Hymenoptera: Platygasteridae); Torymus capite (Hüber)(Hymenoptera: Torymidae); Tetrastichus fumipennis (Girault); Tetrastichus tesserus (Burkes) (Hymenoptera: Eulophidae); and a eulophid of an unknown genus 3 . Three aspects of parasitoid ecology were examined: (1) their trophic relationships with the host and with one another; (2) their temporal sequence of attack; and (3) foraging response to the number of host larvae per gall. All species fed parasitically on the host, but T. capite also feeds on previously parasitized hosts, on gall tissue, and as an adult drinks host haemolymph through a feeding tube. P. solidaginis attacks in the host's egg stage, T. fumipennis during early gall development, and T. capite and T. tesserus later in development. Time of attack may be related to the ability of the parasitoids to penetrate gall tissue. A negative correlation was found between the number of hosts per gall and the percent parasitism inflicted by T. tesserus ; no correlation was found in the cases of T. fumipennis and T. capite .