Are parasitoids limiting the efficacy of the biological control agent (Neomusotima conspurcatalis) (Lepidoptera: Crambidae) on (Lygodium microphyllum), Old World climbing fern?

Lygodium microphyllum, Old World climbing fern, is one of the worst weeds in the Everglades and it is expanding its range in Florida. Vines of L. microphyllum can climb 20 m into trees, outcompete other vegetation, degrade habitat, and alter fire regimes. The brown lygodium moth, Neomusotima conspurcatalis (Lepidoptera: Crambidae), was approved for release as a biological control agent in 2007 and releases began the following year. Large-scale defoliation events occurred shortly after the initial releases of N. conspurcatalis; however, this level of damage is not common. Neomusotima conspurcatalis is currently being mass reared and released as part of the Comprehensive Everglades Restoration Plan (CERP). Ongoing assessment of the field performance of this agent include evaluating if parasitism is limiting its efficacy. Five larval parasitoids were reared from N. conspurcatalis within two years of the initial field releases. The first egg parasitoid, a Trichogramma sp. (Hymenoptera: Trichogrammatidae), was reared from field collected material in 2013 and two pupal parasitoids, including a Brachymeria sp. (Hymenoptera: Chalcididae) and an ichneumonid wasp (Hymenoptera: Ichneumonidae) were collected in 2015. Within egg mass parasitism rates can reach 100 percent and 45 percent of larvae from one field collection were parasitized. Additional research is underway to quantify parasitism rates and determine the impact of parasitism on the population dynamics of N. conspurcatalis.