Effects of a New Insect Growth Regulator, CGA-255′728, on the Different Stages of the Cat Flea (Siphonaptera: Pulicidae)

Abstract

A new juvenile hormone mimic CCA-255'728, developed by Novartis, was tested for its efficacy on different life stages of the cat flea, Ctenocephalides felis (Bouché). The compound was mixed in bovine blood at concentrations of 1, 10, and 100 ppb and fed to adult fleas using an artificial membrane system. Less than 7% of the eggs from fleas fed 10 and 100 ppb hatched, compared with >70% hatch in eggs laid by control fleas or fleas fed 1 ppb. Histological studies demonstrated that approximately 50% of the eggs from fleas fed 10 ppb contained unhatched larvae that died after completing embryological development. At 100 ppb, 24% of the fleas died as fully formed larvae within the egg, but at this concentration nearly 20% of fleas also died before embryogenesis was completed. In addition to embryonic and larval mortality, approximately 28% of eggs from the 100 ppb-treated group were deposited as empty shells. Evidently these eggs were crushed by the muscular action of the oviduct and yolk was expelled into the oviduct during oviposition. None of the test concentrations showed adulticidal effects over a 10-d period. Fecundity was significantly increased with increased concentrations of CGA-255'728 indicating that the compound mimicked the effect of juvenile hormone.

Effect of juvenoids pyriproxyfen and diofenolan on embryogenesis and postembryonic development of blow fly Chrysomya megacephala (Diptera: Calliphoridae) following egg treatment

“…Mondal and Parween (2000) reported ovicidal and embryocidal properties of several IGRs in stored-product insects. Effects of JH mimic CGA-255′728 (Rasa et al 2000) and pyriproxyfen were evaluated on cat fleas. Diofenolan has been reported to be effective against scale insects and lepidopteran eggs of tea pests (Pedigo 2002) where eggs died due to diofenolan exposure as found in the present study.…”

The Biology and Ecology of Cat Fleas and Advancements in Their Pest Management: A Review

“…When eggs and larvae of C. felis exposed to filter papers treated with pyriproxyfen, adult emergence was inhibited at 0.1 μg/m 2 [ 271 ]. CGA-255’728 mimicked the effect of JH, especially at rates >100 ppb, but this compound appears not to have been developed against cat fleas [ 272 ].…”