Lymantria dispar dispar strain:IPLB-LD-652 Genome sequencing and assembly

Since its accidental introduction to Massachusetts in the late 1800s, the European gypsy moth (EGM; Lymantria dispar dispar) has become a major defoliator in North American forests. However, probably because females are flightless, the spread of the EGM across large eastern areas of the United States and Canada has been relatively slow over the past 150 years. In contrast, females of the Asian gypsy moth (AGM; Lymantria dispar asiatica) have fully-developed wings and can fly. They will likely be a fast-spreading economic threat if populations are established in North America. To explore the genetic determinants of these phenotypic differences, we sequenced and annotated a draft genome of both of these two gypsy moths. The 865 Mb gypsy moth genome is the largest Lepidoptera genome sequenced to date and encodes ~13,300 proteins. Gene ontology (GO) analyses of EGM and AGM samples revealed divergence between these populations in genes rich in several GO categories related to muscle adaptation, chemosensory communication, detoxification of food plant foliage, and immunity to viruses. These genetic differences likely contribute to variations in flight ability, chemical sensing, and pathogen interactions among EGM and AGM populations. Finally, we use our new genomic and transcriptomic tools to provide insights into the transcriptional response of the gypsy moth to viral pathogens. Characterizing the immunological response of gypsy moths to virus infection may aid in the improvement of virus-based bioinsecticides currently used to control gypsy moth caterpillars.