JUVENILE-HORMONE ANALOG, S-31183, CAUSES A HIGH-LEVEL INDUCTION OF PRESOLDIER DIFFERENTIATION IN THE JAPANESE DAMP-WOOD TERMITE

The effect of a juvenile hormone analogue, 2-[1-methyl-2(4-phenoxyphen oxy)etho-xy]pyridine (S-31183), on differentiation of the presoldier w as tested with the Japanese damp-wood termite, Hodotermopsis japonica. Sixth and 7th instar larvae were reared on filter papers impregnated with various amounts (10-1000 mug/filter paper) of the analogue for 3 weeks. While presoldiers were induced, with some mortality, under all the conditions tested, the rate of induction was significantly higher (>90%) with lower mortality (< 10%) than under the other conditions wh en 10 mug or 30 mug of S-31183 were administered to the 6th instar lar vae. The length of the premolt interval of larval-presoldier molt was about 5.5 days, equal to that of larval-larval molt.