TREE GROWTH-REGULATOR INFLUENCES ORANGESTRIPED OAKWORM (LEPIDOPTERA, SATURNIIDAE) DEVELOPMENT AND SURVIVAL

The influence ofthe tree growth regulator paclobutrazol a-(1,1-dimethy lethyl)-1H-1,2,4-triazole-1-ethanoll on the growth of willow oak, Quer cus phellos L., and development and survival of orangestriped oakworm, Anisota senatoria (J. E. Smith), was investigated from 1988 to 1990. Paclobutrazol significantly reduced Q. phellos growth, especially 1 an d 2 yr after treatment. The most significant effects of paclobutrazol on A. senatoria development and survival were measured 1 yr after trea tment. Early and late instars differed in their response to paclobutra zol treatments. In laboratory studies, 1 yr after treatment, the highe st rate of paclobutrazol slowed development and decreased survival of early instars compared with control treatments. Paclobutrazol treatmen ts at the two lowest rates significantly increased survival of late in stars and prepupae compared with the highest rate in the laboratory. A ccelerated development in the fifth instar occurred with paclobutrazol treatments. At the lowest rate, paclobutrazol treatment significantly increased female pupal weights when larvae were reared in the laborat ory and field. These data suggested that Q. phellos injected with pacl obutrazol at the two lowest rates may experience a late-instar populat ion that has increased survival, development, and female pupal weight.