Nutritional Ecology: Lymantria Dispar as a Model System for Study of Serum Storage Proteins

The lepidopteran family Lymantriidae contains about 200 genera and about 2,500 described species, mostly from the Old World Tropics (DeWorms, 1983). Of the 46 recognized species and subspecies of Lymantriidae in North America, 30% are considered pests (Ferguson, 1978). The pest species include three introduced species which have become established in North America, the gypsy moth, Lymantria dispar (L.), the browntail moth, Euproctis chrysorrhoea L. and the satin moth, Leucoma salicis (L.). These exotic species are of particular interest to us because of their differing life history strategies and varying levels of success in North America. The satin moth is a minor pest of native and exotic species of poplar, but has on occasion defoliated aspen forests in North America. (Wagner & Leonard, 1979; 1980). The browntail moth is currently a refugial species in several maritime localities in eastern North America (Schaefer, 1974), but populations have recently rebounded (Leonard, 1988). The most successful of the invading Lymantriids is the gypsy moth, which continues to spread in North America. With economically important species of Lymantriidae, a wide variation in the degree of polyphagy exists, from the rather narrow host ranges of the nun moth, Lymantria monacha L., the Douglas-fir tussock moth, Orgyia pseudotsugata (McD.), and the satin moth, to the more catholic appetites of the gypsy moth and browntail moth. Within the wide range of hosts that gypsy moth will feed upon, performance and fitness can vary between species of hosts (Barbosa & Greenblatt, 1981; Barbosa et al., 1981). The quality of a tree host species will differ according to foliage age, location of foliage on the tree, and site conditions. (Wallner, 1987 and references therein.). Leaf quality can decline in response to grazing by gypsy moth larvae (Lance et al., 1986; Schultz & Baldwin, 1982; Valentine et al., 1983; Wallner & Walton, 1979). There is considerable current interest in insect-host interactions encompassing the emerging field of nutritional ecology. As noted by Slansky and Scriber (1985), the amount, rate, and quality of food consumed influences growth rate, developmental time, weight, dispersal ability, and probability of survival; thus, the processes of food consumption and utilization underlie and