Effect of an insect growth regulator, exhibiting juvenile hormone activity, on larvae of a pine-defoliating sawfly, Diprion similis (Hartig).
[See FA 35, 7777] Cecropia juvenile hormone [see FA 38, 4919], applied in acetone to 1st instar larvae of Diprion similis, caused complete mortality before the 4th instar at the highest concn. tested (10 g/litre), with less effect at 0.1 and 1 g/litre. A synthetic hormone mimic had similar effects. The effect of the same concentrations was less on 2nd instar larvae; there was no effect on the 3rd instar.