Biology of Bellura gortynoides (Lepidoptera: Noctuidae), a Yellow Water Lily Borer, in Indiana1

The biology of Bellura gortynoides Walker was studied from May 1973 to June 1974. There were 2 complete generations per year in the Tippecanoe Co., IN area. Eggs were laid in masses on both upper and lower surfaces of emergent leaves of yellow water lily, Nuphar advena Aiton. First generation eggs were laid in late May to early June and were well covered with brownish hair from the female's anal tuft. Eggs hatched within 6 days. For approximately the 1st 3 instars, larvae were leaf miners; thereafter, they became petiole borers. There were usually 6 or 7 instars and ultimate instars averaged about 5 cm in length. First generation larvae pupated in the water-filled tunnels of the petioles. Throughout most of July and August, white-tailed females emerged, mated, and laid 2nd generation egg masses covered with white hair. As in the 1st generation, 2nd generation larvae passed through leaf mining and petiole boring stages. Between mid-September and November, last instar larvae swam to shore and overwintered under the bark of trees, in wood of dead trees, under logs, or in leaf litter. Pupation occurred on shore in late April or May. Both 1st and 2nd generation eggs were heavily parasitized by Telenomus arzamae Riley (Hymenoptera: Scelionidae). First and, to a greater extent, 2nd generation larval populations were limited by the ichneumonid parasite, Campoletis sp., a nuclear polyhedrosis virus, and the microsporidian, Nosema necatrix Kramer. In addition to N. necatrix, overwintering larvae were also killed by parasitic nematodes, Neoaplectana sp., and the fungus, Aspergillus parasiticus Speare. N. necatrix killed a small proportio2n of 1st generation pupae. Female moths were significantly larger in wingspread than ♂ moths. Second generation adults were found to be larger in wingspread, and duller and paler in color than 1st generation adults. The nature of the vertex of adults and the color of the anal tuft of ♀ moths were found to be invalid characters for separating Bellura species.