Effect Of Different Host Plants On Gypsy Moth, Lymantria Dispar L. (Lepidoptera: Lymantriidae), And Its Mechanism

Gypsy moth, Lymantria dispar L., is one of the most important Lepidopteron defoliator pest over the world. It could damage about 500 kinds of plant including conifer tree, broadleaf tree and weeds. Gypsy moth had caused different lost to different plant in its distribution area over the world. Thus, the study on the influence of host plants on the biological characteristics such as development stage, fecundity is very important and has significant meaning on forest.The effect of different plants on gypsy moth development stage, pupal weight and fecundity was studied in laboratory. Host plants preference of first-instar larvae of gypsy moth were studied on 11 families 21 plants by Latin square design analyzed and ten kinds of plant were used to rear gypsy moth separately. Sugar, protein, tannin, flavone, water of the host plant leaves were analyzed and pH were tested. The results showed that first-instar larvae preferred east-liaoning oak, prince rupprecht larch and chinese juniper significantly and the percent of larvae on those trees was 82 percent, 58 percent and 34 percent respectively. There were less larval on chinese pine, juliana lilac, chinese arborvitae, shinyleaf yellowhorn and weeping willow. Host plant had a significant effect on survival rate, development stage, pupal weight, fecundity, feed rate and feces of gypsy moth. The survival rate of gypsy moth fed on wild apricot, east-liaoning oak, dragon spruce, prince rupprecht larch and cathay poplar was 100%, 17% on chinese pine, 13% on chinese juniper. Dead rate of Gypsy moth fed on stiffleaf juniper, japanese pagodatree and ural falsespiraea was 100%. The development stage of gypsy moth ranked from low to high as prince rupprecht larcheast-liaoning oak>prince rupprecht larch>dragon spruce>cathay poplar>chinese pine. Male pupal weight ranked east-liaoning oak> wild apricot > cathay poplar > prince rupprecht larch > dragon spruce > chinese pine >chinese juniper. The fecundity ranked was prince rupprecht larch > east-liaoning oak > wild apricot > cathay poplar > chinese pine > dragon spruce. The feed rate ranked was dragon spruce > wild apricot > east-liaoning oak > chinese pine > chinese juniper > prince rupprecht larch > cathay poplar. The feces rank was chinese pine > dragon spruce > east-liaoning oak > prince rupprecht larch > wild apricot > cathay poplar> chinese juniper. Growth index of gypsy moth in the...