The effects of juvenile hormone analogues on the embryogenesis of Drosophila melanogaster

Two juvenile hormone analogues (JHA), 6,7-Epoxy-3-methyl-7-ethyl-1-(3,4-(methyl-enedioxy)phenoxy)-2-cis/trans-octene (Hoffman-LaRoche RO 20-3600) and 6,7-Epoxy-3,7-dimethyl-1-(p-ethyphenoxy)-2-cis/trans-octene (Stauffer R-20458), produced embryonic and some first larval instar lethality when topically applied to freshly laid Drosophila eggs at concentrations above 0·1μg RO-20-3600/μl acetone or 1·0 μg R-20458/μl acetone. With progressively later JHA treatments during embryonic development, lethality decreased while the proportion of larvae dying at the time of hatching increased. No delayed postembryonic lethality was observed after the first larval instar. JHA applications to freshly laid eggs produced abnormal head and tracheal formation in some embryos treated with RO-20-3600 and caused developmental arrest during the beginning of posterior gut formation in most eggs treated with R-20458. Treatment with either JHA after the beginning of blastoderm formation resulted in normal looking first instar larvae which failed to hatch.