Evaluation of the toxic effect of insecticide chlorantraniliprole on the silkworm <i>Bombyx mori</i> (Lepidoptera: Bombycidae)

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, bio-assays 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 produced thin-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.

Chlorantraniliprole against the black cutworm Agrotis ipsilon (Lepidoptera: Noctuidae): From biochemical/physiological to demographic responses

“…Chlorantraniliprole is a novel anthranilic diamide insecticide developed by DuPont Crop Protection that has been registered and effectively used for the control of many lepidopteran pests and non-lepidopteran species, such as Coleoptera, Diptera, Hemiptera and Isoptera species in various crops 7,8 . Chlorantraniliprole has a unique mode of action, activating the unregulated release of internal calcium stores, which leads to Ca 2+ depletion, feeding cessation, lethargy, muscle paralysis, and insect death 9 .…”

Neem oil ( Azadirachta indica A. Juss) affects the ultrastructure of the midgut muscle of Ceraeochrysa claveri (Navás, 1911) (Neuroptera: Chrysopidae)

“…A similar effect was observed in Bombyx mori. Munhoz et al (2013) described larvae that had difficulty in eliminating excrement and exhibited a disorganization of the muscles fibers of the midgut, possibly due to the disarray of their myofibrils after the ingestion of insecticide chlorantraniliprole during the larval stage.…”

Morus alba: Host reaction for Meloidogyne javanica, biological nematicides assessment and study of these relationships with yield and quality of leaves, cocoon and health of the silkworm

“…https://doi.org/10.1371/journal. pone.0252987 and to the adequate management of the mulberry leaves offered to the silkworms, which must be free of any agrochemical residues [3][4][5][6]. By this way, the volume and the quality of the mulberry leaves are of extreme importance to the success in obtaining high quality cocoons.…”

“…Sericulture involves the crop of mulberry leaves ( Morus alba ), the silkworm ( Bombix mori ) cultivation and the spinning. The quality of silk, as well as the yield of cocoons, is directly related to nutritional factors and to the adequate management of the mulberry leaves offered to the silkworms, which must be free of any agrochemical residues [ 3 – 6 ]. By this way, the volume and the quality of the mulberry leaves are of extreme importance to the success in obtaining high quality cocoons.…”