Effect of 3 insect growth regulators on larval development,fecundity and egg viability of the coccinelidChilocorus bipustulatus [Col.: Coccinelidae]

The effect of 3 insect growth regulators — methoprene, diflubenzuron and RO 13-5223, on the coccinelidChilocorus bipustulatus L. was studied in the laboratory. Feeding onChrysomphalus aonidum (L.) orAspidiotus hederae Vallot (Diaspididae) treated with the IGRs at the concentration of 0.025% a.i. revealed the following: diflubenzuron caused a complete mortality of 1 st instar larvae; methoprene and RO 13-5223 did not arrest larval development but inhibited pupation; fecundity of sexually mature females was not affected by the 3 IGRs but egg hatch was completely inhibited; egg viability was regained when IGR-exposed females had been transferred to an uncontaminated environment.