Levels of biological control of Synanthedon pictipes (Lepidoptera: Sesiidae) by hymenopteran parasitoids in commercial, non-commercial and natural settings

Reports of parasitoid activity against the lesser peachtree borer, Synanthedon pictipes (Lepidoptera: Sesiidae), are uncommon. Many reports exist only as obscure host records and rarely discuss S. pictipes from a conservation management perspective. Here we sought to assess the relative parasitoid activity against S. pictipes pupae exposed to three different field environments: conventionally managed and abandoned peach orchards and unmanaged woodlots. Cut peach limbs, in which late instar S. pictipes were reared, were placed in the different settings for 14 days, taken to the laboratory and observed for moth or parasitoid emergence. Low numbers of parasitized S. pictipes were recovered and all of those were from woodlots. Although insecticide applications to peach orchards are likely to negatively impact parasitoids, it's also likely that low plant species diversity in orchards contributes to diminished parasitoid activity.