Scrutinizing biological control survey data from the native range – the phylogeny and Lygodium fern host associations of Musotiminae moths

Abstract

Lygodium microphyllum is considered one of the most damaging environmental weeds in Florida. Despite substantial efforts to control this fern, it continues to spread rapidly through the Greater Everglades ecosystem and other regions of Florida. Biological control is considered a critical component of the management strategy to control this weed, and foreign exploration for natural enemies is ongoing. A number of crambid moths from the subfamily Musotiminae are considered the most promising of the potential biological control agents found to date, because they are relatively abundant on Lygodium and apparently host-specific. We amplified three genes (COI, 18S rRNA and 28S rRNA) to assess the phylogenetic relationships among these moths in relation to geography. Limited genetic structuring was typical within each moth species, and no obvious signals of unrecognised host-specific cryptic species were detected, though further investigation is required, particularly for Eugauria albidentata. Our results emphasize the value of complementing initial field surveys with molecular screening, as such an approach provides valuable information on the biogeographic distribution, genetic structuring, and field host range of potential biological control agents.