Infection sites of the entomopathogenic fungus Beauveria bassiana in the larvae of the mosquito Aedes aegypti
Autor(es): Miranpuri, G. S.; Khachatourians, G. G.
Resumo: A series of experiments were conducted to determine the infection sites of the entomopathogenic fungus Beauveria bassiana after ingestion by the larvae of Aedes aegypti. The timing of the host death in relation to larval molting, the principle sites of fungal infection and development in host tissues were studied. Fungal conidiospores (CS) and blastospores (BS) were used separately for treatment of mosquito larvae. Although in most instances CS germinated and developed within the host, in others there was a premature abortion of the fungal development cycle. On the other hand, BS ingested by the larvae showed differences in the fungal development stages in the larval tissues. While the two primary infection sites were the head and the anal region, the most preferred site for fungal development was the larval gut. No more than two cycles of fungal development can occur in the host. Although both CS and BS are effective as larvicides, BS is far more pathogenic.Original Abstract: Emplacement d'infection des larves des moustiques Aedes aegypti avec des champignons Beauveria bassiana Une serie d'experiences a ete menee afin de determiner les emplacements d'infection du fongus entomopathogenique Beauveria bassiana (souche GK 2016) lequel avait ete ingeste des larves d' Aedes aegypti. On a etudie le moment de la mort des hotes en relation des mues des larves, les emplacements principaux ou se conduit l'infection fongale et le developpement du fongus dans des tissus divers d'hote. On a utilise les conidiospores (CS) et les blastospores (BS) separement pour traitement des larves des moustiques. Bien que dans la plupart des cas CS ait germine et se soit developpe chez l'hote, en d'autres cas, CS a germine mais n'avait pas produit du BS evidemment grace a l'avortement premature du cycle de developpement des fongus chez l'hote. Le BS qui avait ete ingeste dans les larves presentait des stages differents de developpement du fongus dans les tissus des larves. Quoique les deux emplacements principaux etaient la tete et la region anale, l'emplacement prefere pour le developpement du fongus etait l'intestin des larves. Nous montrons qu'il n'y a plus de deux cycles de developpement du fongus chez l'hote. Bien que CS et BS soient efficaces comme larvicides, BS est de loin plus pathogene.
Palavras-Chave: Pesticides; Disease control; Larvae; Larval development; Digestive tract; Developmental stages; Conidia; Molting; Infection; Larvicides; Aedes aegypti; Beauveria bassiana
Imprenta: Entomologia Experimentalis et Applicata, v. 59, n. 1, p. 19-27, 1991.
Descritores: Aedes aegypti - Larvicide
Data de publicação: 1991
