The influence of ant attendance on larval parasitism in hawthorn psyllids (Homoptera: Psyllidae)

Abstract

The influence of ant attendance on parasitization of the larvae of three hawthorn psyllid species [Cacopsylla peregrina Förster, C. melanoneura Förster, C. crataegi (Schrank)] was studied over 2 years. All three psyllid species had low parasitization rates. However, the ant-attended C. crataegi was almost exclusively parasitized by Prionomitus mitratus (Dalman) (Hymenoptera: Encyrtidae) while the unattended C. peregrina and C. melanoneura were predominantly attacked by P. tiliaris (Dalman). Additionally, C. peregrina and C. melanoneura has significantly higher hyperparasitization rates than the ant-attended C. crataegi, with Pachyneuron muscarum as the dominant hyperparasitoid of all three psyllids. The mummies of C. peregrina and C. melanoneura were also heavily attacked by anthocorids. Both Prionomitus tiliaris and P. mitratus were disturbed and jumped away when encountering foraging ants. However, ant exclusion experiments showed that the primary parasitoid P. mitratus benefitted from ant attendance of its host C. crataegi as honeydew-collecting ants provided it with protection from hyperparasitoids. © 1994 Springer Verlag.