Susceptibility of Bagworm Metisa plana (Lepidoptera: Psychidae) To Chlorantraniliprole

Bagworm (Metisa plana) is an ubiquitous pest in oil palm plantations. Seven insecticides were evaluated for their effectiveness in controlling M. plana using a leaf dip bioassay. The evaluation assessed the speeds of action, susceptibility of different instars, ovicide and ovi-larvicide activity of chlorantraniliprole. The lowest LC50 (0.25ppm) was found with chlorantraniliprole and trichlorfon, followed by thiamethoxam with 0.70 ppm, indoxacarb with 0.72 ppm, cypermethrin with 0.90 ppm, and for monocrotophos with 15.03 ppm. The highest LC50 (18.58 ppm) was found for Bacillus thuringiensis, which was approximately 74 times larger than trichlorfon and chlorantraniliprole. Meanwhile, the speed of action of these insecticides on M. plana larvae was also found to differ. Trichlorfon (1900.0 ppm), chlorantraniliprole (50.0 ppm) and cypermethrin (75.0 ppm) were among the three fastest acting insecticides evaluated, with respective LT50 values of 12.66, 17.04 and 28.63 minutes and larval mortality of 19.91, 47.27 and 53.06 minutes after exposure to the chemicals. Bacillus thuringiensis (324.0ppm) was the slowest acting insecticide, requiring more than 2000 minutes to kill 50% of M. plana larvae. The first three instars of M. plana larvae were very susceptible to chlorantraniliprole, with LC50 below 1 ppm, as compared to LC50 of 1.91ppm and 9.62ppm for the 4th and 5th instar larvae. Chlorantraniliprole had low to moderate ovicidal effects on M. plana, which caused egg mortality to range from 27.50% to 72.50%, but it was shown to be highly toxic on the neonates emerging from the eggs