Parasitoid assemblage associated with a North American pine weevil in South Africa

Abstract

The weevil Pissodes sp. was first reported as an introduced pest on exotic Pinus spp. in South Africa in 1942. It is only recently that the native wasp Pycnetron pix Prinsloo was described from South Africa as a parasitoid of this weevil. We estimated the frequency and distribution of the association between P. pix and Pissodes sp., and the occurrence of possible other natural enemies. Parasitoids were reared from Pissodes-infested Pinus radiata D. Don and P. patula Schiede ex Schltdl. & Cham logs collected from major Pinus-growing regions. The identity of parasitoids was confirmed using morphological and molecular techniques. Parasitism was confirmed by analysing gut content sequences of parasitoids. Pycnetron pix was found parasitizing Pissodes sp. throughout major Pinus-growing provinces of the country. Another native parasitoid, Cratocnema sp., is reported for the first time as a parasitoid of Pissodes sp. Rhopalicus tutela (Walker), a known parasitoid of Pissodes spp. in their native range, was also detected and confirmed to be of European origin. Though characterized by erratic distribution and low parasitism rate, an accruing suite of natural enemies was documented, suggesting that there is potential for augmentative biological control of Pissodes sp. in South Africa.