Distinct parasitoid communities associated with host races of the leaf-mining moth Acrocercops transecta on distantly related host plants (Juglandaceae and Ericaceae)

Differences in host-plant species may affect the structure of parasitoid communities of phytophagous insects. Phytophagous insect species often consist of host races, and comparisons between host races enable us to infer the effects of host-plant differences on parasitoid communities. Here, we compare the parasitoid fauna of two host races of the leaf-mining moth Acrocercops transecta, which are associated with either Juglandaceae or Lyonia ovalifolia (Ericaceae). Field collection and subsequent laboratory rearing revealed a significantly higher parasitization ratio in the Juglandaceae race than in the Lyonia race. In the Juglandaceae race the majority of parasitoids were Braconidae, whereas in the Lyonia race the majority were Eulophidae. Furthermore, even within the same host race the most abundant parasitoid species differed between populations with different host associations. Hence, the present results strongly indicate that different host-plant taxa affect the structure of parasitoid communities even within a single phytophagous insect species.