Disruption of development on Triatominae bugs by action of juvenile hormone analogues
Stoka, A.M.
Revista Argentina de Microbiologia 20(1 Suppl): 86-90
1988
ISSN/ISBN: 0325-7541 PMID: 3138739 Document Number: 309476
To sidestep the breakdown of juvenile hormone analogues (JHAs) which possess methyl ester groups by the JH esterases produced naturally by living triatomines, workers at the author's laboratories synthesised JHA derivatives in which the methyl ester group was substituted with a carbamate, carbonate, thiolcarbamate, carbonyloxyimino or thiocarbonyloxyimino functional group. When tested on eggs and 5th-instar nymphs of Rhodnius prolixus, one of the synthesized JHA-carbonates showed ovicidal activity nearly as high as that of the growth regulator fenoxycarb. These and other JHA derivatives showed various levels of toxicity to different stages and species of triatomines which could not be predicted empirically. In tests of fenoxycarb on R. prolixus eggs, however, it was found that exposure to 500 ng/egg on post-oviposition day 0, 1, 2, 3 .. and 9 inhibited 100%, 100%, 50%, 70% .. and 0%, respectively. The author concludes that the advantages of using JHAs during surveillance activities of control programmes of Chagas' disease would be (a) low environmental contamination, i.e. low toxicity to man and domestic animals, (b) decreased vectorial capacity (i.e. even if they show prolonged survival, juvenilized triatomines may have lowered susceptibility to Trypanosoma cruzi), and (c) lower costs, according to market values of neurotoxic insecticides.