Influence of rainfall on feeding behavior, growth, and mortality of larvae of the beech caterpillar, Quadricalcarifera punctatella (Motschulsky) (Lep., Notodontidae)

A series of observations and experiments were conducted to examine the direct influence of rainfall on feeding behavior, growth, and mortality of larvae of the beech caterpillar, Quadricalcarifera punctatella . Rainfall restricted feeding, especially of the young larvae; first and second instars stopped feeding and moved to the backside of a leaf and/or to another leaf when rain began. More than 90 % of hatched larvae died of starvation under a condition of experimentally man‐made continuous rain. Last instar larvae stopped feeding in a heavy rain but more than half of them continued to feed when rain was light. Larvae reared under the man‐made continuous rain during their last instar stage weighed 14.722.0 % less than control when they matured and pupated, and those reared under the rain during the 1st instar stage were also small when they molted to the 2nd instar, undergoing one extra instar stage before the last instar. This extra stage lengthened the overall larval duration but body size regained when subsequent conditions were more favorable. Thus, rainfall in young larval stages resulted in high mortality and a prolongation of the larval period, and rainfall in late larval period curtailed body growth.