European Gypsy Moth Lymantria Dispar L Outbreaks PDF Download

Gypsy moth, Lymantria dispar dispar (Linnaeus) (Lepidoptera: Erebidae), is an exotic invasive species introduced from Europe that is spreading south and west in North America. In spring and early summer, gypsy moth caterpillars feed on the leaves of many different tree species, especially oaks. During outbreaks, caterpillars defoliate entire forests. Most broadleaf trees produce new foliage in response to defoliation more than 50 percent, allowing them to resume photosynthesis. Defoliation weakens trees, which renders them more susceptible to secondary mortality agents. Gypsy moth can also directly kill trees, especially if severe defoliation persists for multiple successive seasons. In some years, outbreaks can be massive with defoliation exceeding several million acres. If extensive tree mortality occurs, outbreaks can contribute to shifts in forest species composition toward dominance by immune host species. Several related moth species, including L. albescens, L. mathura, L. monacha, L. postalba, L. umbrosa, and two other subspecies of gypsy moth, L. dispar asiatica and L. dispar japonica, the Asian gypsy moth, do not have established populations in North America. Of these, Asian gypsy moth subspecies, L. dispar asiatica and L. dispar japonica, have been the most frequently intercepted and accidentally introduced subspecies in North America. Asian gypsy moth surveillance and eradication have been particularly critical because these subspecies have broader host ranges than their European counterpart, and unlike the European subspecies, females are capable of flight.