The activity of juvenile hormone mimics for the eggs of Rhodnius prolixus

Twenty four juvenile hormone (JH) mimics of several different chemical classes were applied to freshly laid eggs of Rhodnius prolixus. Activity of the JH mimics was assessed in terms of their ability to inhibit eclosion. All chemical classes tested except one of the natural JHs and two very closely related long chain compounds contained members which inhibited eclosion; the most active chemicals were derivatives of geranyl para-aminobenzoic acid esters and aryl methylene dioxyphenyl ethers. In general, those chemicals of a particular class which had highest morphogenetic activity when applied to last instar larvae, were also most active in inhibiting eclosion. However, not all structure/activity relationships of JH mimics for last instar larvae were applicable to eggs; in particular the presence of a terminal epoxide group increased activity greatly for eggs but only slightly for last instar larvae. The dose per unit weight to inhibit eclosion is far greater than the equivalent dose to disrupt normal metamorphosis.