R.K. MOUDGAL, SUCHETA KHOKHAR AND B. DAHIYA

Diflubenzuron was tested against eggs (0-24, 24-48 and 48-72 hours old), larvae (II & V instars) and pupae (0-2 days old) of cabbage semilooper, Thysanoplusia orichalcea (Fab.) Unhatched eggs ranged from 34.67-100.00, (0-24 h) 30.67- 77.33 (24-48 h) and 28.00-73.33 (48-72 h) per cent when exposed to different concentrations (50, 100, 150, 200 and 250 ppm). The per cent larval mortality ranged from 28.00-58.00 and 28.00-50.00 for IInd and V instar larvae, respectively as against 14.00 and 12.00 per cent in untreated control, when exposed to concentrations of 50, 100, 200, 500 and 1000 ppm applied by feeding and ingestion methods. Tested compound showed prolonged larval duration, extended pupal period and decreased adult emergence of T. orichalcea through larval treatment. Similarly, pupal exposure to this compound resulted in prolonged pupal period and reduced adult emergence. Besides a number of morphological deformities were also observed in all treated juvenile stages (eggs, larvae and pupae).