Discovery of 2 platygastrid species parasitizing Contarinia maculipennis (Diptera: Cecidomyiidae) from Okinawa, Japan

Contarinia maculipennis Felt (Diptera: Cecidomyiidae) is an invasive pest from Southeast Asia, and it has a wide host range across 7 plant families. In Okinawa, this species infests flower buds of Dendrobium phalaenopsis, Dendrobium spp. (Orchidaceae), and Momordica charantia (Cucurbitaceae). During the rearing experiments of C. maculipennis larvae, we obtained 2 endoparasitoid species belonging to the genus Synopeas (Hymenoptera: Platygastridae). This platygastrid species that parasitized C. maculipennis larvae in Dendrobium flower buds differed from another species that parasitized C. maculipennis in Momordica flower buds. Although many platygastrids have been known to be parasitoids of various cecidomyiid species, this is the first record of platygastrids attacking C. maculipennis. There are 2 possibilities regarding the derivation of these parasitoids. One possibility is that they have been accidentally introduced to Okinawa together with Dendrobium and gall midge larvae. Another possibility is that these parasitoids are native species and have expanded their host range from unknown native insects to C. maculipennis.