β-Ecdysone Effects on the Camel Tick, Hyalomma Dromedarii (Acari: Ixodidae)12

Abstract

Topically applied β-ecdysone is lethal to feeding and engorged nymphs and to unfed and feeding adults of Hyalomma dromedarii in 10- and 20-μg doses. Premolting mortality was higher in nymphs treated while feeding than in those treated postengorgement. The 10- and 20-μg doses caused accelerated molting in all nymphal groups; the 1- and 5-μg doses also produced this effect in nymphs treated while feeding. No alteration in adult sexual behavior was observed. Twenty micrograms applied during adult feeding caused a drastic reduction in fertility of both sexes. Reductions in male fertility were also noted when nymphs were treated 10 days postengorgement with 1-, 5-, 10-, and 20-μg doses.