Standardization of in VITRO Test and efficacy evaluation of different concentrations of pyriproxifen in the control of the development of Cochliomyia Hominivorax
Insect growth inhibitors; analogue of juvenile insect hormone; control of the pestle fly.
Cochliomyia hominivorax is the main fly causing primary myiasis and responsible for significant economic losses in livestock. Its larval forms can parasitize any warm-blooded animal, but the most relevant species is bovine, since losses related to parasitism can reach millions of dollars per year. It is endemic in most of South America, and collective efforts and integration to countries already eradicated by the fly have been studied in order to apply a better method of control. Despite the great contribution of synthetic insecticides to increasing agricultural production, many problems arising from their intensive, incorrect and indiscriminate use during several consecutive decades have occurred, such as the presence of toxic residues in food, intoxication of rural producers and consumers, contamination of water and soil, selection of resistant pests and damage to populations of non-target organisms. As a new control alternative, pyriproxifen, a substance of the IGR class, has been challenged against some dipterous species. In the present study, concentrations of 0.05%, 0.15% and 0.45% of pyriproxyfen, incorporated into the larval medium, were tested, challenging larvae (L1) of C. hominivorax and favoring the development of the cycle to follow which stage it would demonstrate insecticide effect. Before developing the methodology used to test the product, a study was carried out to standardize the in vitro methodology to be used. Based on these results, it was possible to follow the development of the cycle and to observe in which stage piriproxifen had action in the concentrations used.