Trophic influence on the development of the gypsy moth (Lepidoptera, Lymantriidae) and the forecast of its abundance

Results of a long-term investigation on the development of the Armenian population of Lymantria dispar L. are reported. A list of host plants with their comparative characteristics and data on their effect on different developmental phases of the pest (larvae, pupae, adults, and embryos) are given. Biochemical changes in the leaves of host plants are shown to play a significant role in regulation of the L. dispar population density. Population growth can be expected when population develops on primary hosts with sufficient content of nutrients in the leaves and a certain carbohydrate to protein ratio, as well as a certain ratio of water-and alkali-soluble protein fractions. Intense weakening of the plants caused by the larval feeding affects the food value of the leaves and, subsequently, the pest metabolism, negatively affecting its general physiological condition and fecundity, which eventually results in decline of the pest population.