The citrus swallowtail Papilio demoleus L. is a serious pest of citrus in many regions of the world. We evaluated the effects of pyriproxyfen, a juvenile hormone agonist, on late-stage larval and pupal development of the pest. Fourth and fifth instars, as well as freshly formed prepupae were treated topically with concentrations of 7.5–60 μg/μl of the juvenile hormone analogue. Effects included prolongation of larval duration, delay in larval–larval and larval–pupal ecdysis, mortality, formation of mosaics with larval, pupal and adult characteristics, decreased and imperfect pupation, and complete inhibition of emergence. These results demonstrate that pyriproxyfen has an adverse effect on the development and metamorphosis of the citrus swallowtail, and further work is recommended, including laboratory and field studies.

The effect of topical application and oral administration of diflubenzuron on the feeding budget in the fifth instar larva of Papilio demoleus has been studied. The LD50 and LC50 values of diflubenzuron were 13.50 and 9.00 μg/larva/48 hr respectively. Topical application was found more efficacious in producing 50% mortality at a comparatively minimum dose of 9.00 μg. The growth efficiency was reduced by 44.54% in oral administration and 38.19% in topical application at the highest sublethal dose over that of control larvae. Not only the growth of the larvae of P. demoleus was inhibited, but the adults showed morphological deformities.