STUDIES ON THE MODE OF ACTION OF BUPROFEZIN .2. EFFECTS ON REPRODUCTION OF THE BROWN PLANTHOPPER, NILAPARVATA-LUGENS STAL (HOMOPTERA, DELPHACIDAE)

The effects of buprofezin on the life span and reproduction of N. lugens were examined by allowing adults of different ages to feed on rice plants treated with the chemical. Irrespective of adult age at the time of inoculation on the treated plants, the number of nymphs of the next generation was decreased to 0-6% of the control by 250 ppm buprofezin and to 0-2% by 1000 ppm. The treatment to adults within 24 of emergence considerably inhibited oviposition without interrupting ovarian development and shortened the life span of female adults. Although the treatment to older adults did not affect oviposition, it inhibited the embryo development of deposited eggs, which reached the eye pigmentation stage but failed to hatch.