TITLE:
Evaluation of the toxic effect of insecticide chlorantraniliprole on the silkworm Bombyx mori (Lepidoptera: Bombycidae)
AUTHORS:
Roxelle Ethienne Ferreira Munhoz, Thaís Souto Bignotto, Naiara Climas Pereira, Cláudia Regina das Neves Saez, Rafaela Bespalhuk, Verônica Aureliana Fassina, Graziele Milani Pessini, Mayarha Patrícia Dequigiovanni Baggio, Lucinéia de Fátima Chasko Ribeiro, Rose Meire Costa Brancalhão, Shunsuke Mizuno, Willian Shigeaki Aita, Maria Aparecida Fernandez
KEYWORDS:
Silkworm, Pesticide Drift; Mortality; Symptomatology; Chlorantraniliprole
JOURNAL NAME:
Open Journal of Animal Sciences,
Vol.3 No.4,
November
29,
2013
ABSTRACT:
The
silkworm Bombyx mori feeds
exclusively on mulberry leaves and is highly sensitive to pesticides in general.
Although mulberry plantations are free of agrochemicals, pesticide drift can
occur. Chlorantraniliprole, a novel insecticide of the anthranilic diamides
class, has been used to control pests in field crops. In this study, we
investigated the biological effects of different concentrations of chlorantraniliprole
on B. mori silkworm commercial
Brazilian hybrids. To evaluate the toxicity of chlorantraniliprole, bioassays
were carried out and data on the lethal concentrations, symptomatology, morphology
and variables of silk production were collected. Results indicated that B. mori is extremely sensitive to
chlorantraniliprole, even in low concentrations. The highest silkworm mortality
rates were observed in the two highest chlorantraniliprole concentrations, 0.2
and 0.1 ppm. Although lower chlorantraniliprole concentrations did not cause
death of all the silkworm larvae, various symptoms of toxicity were observed:
feeding cessation, regurgitation, late development and incomplete ecdysis. Such
symptoms reflect the morphological changes we observed in the midgut
epithelium, which affected nutrient uptake and metabolism, and even the production
of cocoons. Exposed larvae also producedthin-shelled
cocoons, which constitutes a serious economic problem because this type of
cocoon is not useful for the silk industry. The results provided herein confirm
the toxicity of chlorantraniliprole in silkworm larvae. Therefore, we strongly
suggest that, competent authorities of the National Health Surveillance Agency,
in pesticide management should take measures to reduce or eliminate the use of
chlorantraniliprole in areas nearest to silkworm cultivation.