EFFECT OF AN ECDYSONE AGONIST, RH-5849, ON WANDERING BEHAVIOR IN SPODOPTERA-LITTORALIS

1. Wandering behaviour of the fall armyworm, Spodoptera littoralis has been examined using a video digitizing computer system. 2. Ecdysteroi d titers prior to and during wandering have been determined using an e nzyme immunoassay. 3. RH 5849, an agonist of 20-hydroxyecdysone (20E) applied at various times before wandering to last instar larvae of S. littoralis caused a delay in the onset of wandering, varying from 0.5 to 4.5 hr. This delay was dose dependent. 4. We suggest that wandering in S. littoralis may be induced by a decrease in ecdysteroid titers.