Histochemical and ultrastructural evidence of lipid secretion by the silk gland of the sugarcane borer Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae)

Abstract

Neotropical Entomology 36(5): 707-711 (2007) Evidências Histoquímicas e Ultra-Estruturais de Secreção Lipídica pela Glândula da Seda da Broca da Canade-Açúcar, Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae)RESUMO -A glândula da seda de larvas de Lepidoptera é responsável pela produção da seda usada na secreção de seda de insetos, embora a presença desse componente contribua para a resistência da seda secreção da glândula da seda de larvas de Diatraea saccharalis (Fabricius), bem como caracterizar a região glandular responsável pela secreção. A glândula da seda foi submetida a procedimentos histoquímicos para detecção de lipídeos e convencionalmente preparada para análise ultra-estrutural. Gotas lipídicas foram histoquimicamente detectadas no citoplasma apical de células da região anterior e no lúmen, entre os microvilos. A análise ultra-estrutural da região anterior mostrou material lipídico, visualizado como com sericina; material semelhante foi observado dentro do lúmen, adjacente aos microvilos. Nenhum componente secretor lipídico foi detectado nas células ou no lúmen da região posterior. Os resultados sugerem que a seda produzida pela D. saccharalis tem, pelo menos, um discreto componente lipídico, que é secretado pela região anterior, junto com a sericina.PALAVRAS-CHAVE: Célula secretora, inseto, larva, lipídio ABSTRACT -The silk gland in Lepidoptera larvae is responsible for the silk production used for shelter characterizes the glandular region and detects the presence of lipid components in the secretion of the silk gland of Diatraea saccharalis detected in both the apical cytoplasm of cell of the anterior region and in the lumen among the microvilli.neither in the lumen of the posterior region. Our results suggest that the silk produced by D. saccharalis

Critical electrolyte concentration of silk gland chromatin of the sugarcane borer Diatraea saccharalis, induced using agrochemicals

“…Differences among the 3rd-instar larvae may occur because during the 5th instar of larval development, the silk gland is highly active synthetizing silk (Victoriano and Gregório, 2002;Victoriano et al, 2007) to weave a cocoon for pupation.…”

“…In the larval stage, the insect has a pair of silk glands that are responsible for the production of silk, which is fully developed in the last instar of larval development (Victoriano and Gregório, 2002;Victoriano et al, 2007).…”

Comparison of Silk Glands of Diapause and Non-Diapause LarvalSitodiplosis mosellana

“…The structure of insect silk glands has been well studied in Lepidoptera (Akai 1984), Hymenoptera (Silva-Zacarin 2003, Serrão 2005, Victoriano 2007), and especially Bombyx mori , because its silk has great economic value (Iijimaa 1972, Sasaki and Tashir 1976, Sehnal and Akai 1990). The above studies indicated that the major components of the silk or cocoon secreted by the silk gland were friboin and sericin (Akai 1984).…”

“…The above studies indicated that the major components of the silk or cocoon secreted by the silk gland were friboin and sericin (Akai 1984). Victoriano (2007) suggested that the silk produced by Diatraea. saccharalis has minor lipid contents and sericin, and that the lipid makes the cocoon waterproof.…”

“…The silk glands of insects are responsible for the secretion of the silk used for shelter or cocoon formation (Sehnal and Akai 1990, Victoriano 2007). In cocoon-making insects, the silk glands, which secrete a protein or viscid liquid that hardens into silk upon exposure to air, play a vital role in protecting the insect from adverse environmental conditions (Sasaki and Tashiro 1976, Akai 1984, Silva-Zacarin et al 2003).…”