SUITABILITY, DIGESTIBILITY AND ASSIMILATION OF VARIOUS HOST PLANTS OF THE GYPSY-MOTH LYMANTRIA-DISPAR L (LEPIDOPTERA, LYMANTRIIDAE)

Development and survival of gypsy moth (L. dispar) larvae is strongly influenced by the host plant upon which they feed. The most rapid development and largest pupae were produced from grey birch-fed larvae. Beech- and maple-fed larvae produced the smallest pupae while maple-fed larvae exhibited prolonged development. White and red oak-fed larvae exhibited development and pupal weights intermediate between the above 2 groups. Approximate digestibility (AD) and efficiencies of conversion of food (ECD and ECI) were generally highest among grey birch-fed individuals. The utilization of the relatively closely related oak species, as reflected in AD and ECD values, differed. Leaves were examined for 14 elements. The content of each element varied among host plant species and over time. N levels were highest in grey birch and dropped over time in all host plants.