Controlled-Release Reservoir Systems for the Delivery of Insect Steroid Analogues Against Ticks (Acari: Ixodidae)1

Abstract

Controlled-release reservoir systems for the delivery of insect steroid analogues (ecdysteroids) have been developed and evaluated against ticks. Effects on the tick Hyalomma dromedarii of ecdysteroids released into the blood of host rabbits with implants were determined. The most important effects were (1) mortality of larvae, (2) reduced mean weight of surviving engorged nymphs, (3) accelerated molting of fed nymphs, and (4) increased pheromone production by females and initiation of pheromone production by males. The ability to deliver potent bioactive compounds of this type via host implants has important implications for future control strategies, especially for tick parasites of livestock.