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Histology and ultrastructure of Aedes albopictus larval midgut infected with Bacillus thuringiensis var. israelensis
Author(s) -
Silva Vanderlei C.,
Pinheiro Nadja L.,
Scherer Paulo O.,
Falcão Simone S.,
Ribeiro Vinicius R.,
Mendes Rosa Maria M.,
Chagas Rodrigo,
CardozoDeAlmeida Margareth,
Dos SantosMallet Jacenir Reis
Publication year - 2008
Publication title -
microscopy research and technique
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 118
eISSN - 1097-0029
pISSN - 1059-910X
DOI - 10.1002/jemt.20605
Subject(s) - midgut , biology , endoplasmic reticulum , aedes albopictus , ultrastructure , basal lamina , vacuolization , bacillus thuringiensis , cytoplasm , microbiology and biotechnology , anatomy , aedes aegypti , larva , botany , bacteria , genetics , endocrinology
Histological and ultrastrucutural alterations in the midgut of Aedes albopictus larvae infected with Bacillus thuringiensis var. israelensis (Bti) were observed by light and transmission electron microscopy (TEM). Two formulations of Bti were used: granulated and powder, with 0.2% active ingredient in 90 larvae of Ae. albopictus distributed in three containers containing 30 larvae each (one control group and two test groups). The midgut epithelium of the control group presented flattened and elongated cells with mace‐shape with a narrow base. Midgut epithelium cells' surface was convex and had a large circular nucleus located in the median‐apical portion of the cell. These cells also presented a basal lamina with a small accumulation of extracellular fibrous matrix, thus characterizing a basal membrane, with a muscle layer and a peritoneal membrane more externally. After Bti ingestion, the larvae stopped/slowed their natural movements down in 5 min. After 30 min approximately, the swimming movements stopped completely. Internally, the intestinal cells showed a disorganization of the basal processes, dilatation and fragmentation of the rough endoplasmic reticulum, with intense cytoplasmic vacuolization. There were concentric dense laminas accumulated in the cytoplasm, and these residual membranous bodies were seen greatly increased in size after 60 min. Mitochondria, fragments of rough endoplasmic reticulum and other remainder organelles were surrounded and segregated from the cytoplasm by exocytosis. This article reports the histopathological alterations in the midgut of Ae. albopictus after infection with Bti and contributes to a better understanding of the mode of action of this bacterial strain used as bioinsecticide against mosquito larvae. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.