Mode of infection of the corn earworm (Heliothis zea) by Beauveria bassiana as revealed by scanning electron microscopy

doi:10.1016/0022-2011(79)90069-7

Journal of Invertebrate Pathology

Volume 34, Issue 3, November 1979, Pages 238-247

https://doi.org/10.1016/0022-2011(79)90069-7 Get rights and content

Abstract

Conidia from highly pathogenic mutants of Beauveria bassiana germinate quickly (within 18 hr) on the surface of corn earworm larvae (Heliothis zea) and immediately begin penetration of the cuticle. Enzymes produced by the penetrating hyphae degrade the cuticle since holes are formed at the point of entry. Clustering of conidia around nodules of larvae is often seen, but penetration is not restricted to such areas. Direct evidence is presented to show that conidia can also germinate inside of spiracle openings and could invade larvae by this route. Once inside the hemocoel, the fungus multiplies extensively; however, larval death occurs with only minimal breakdown of internal tissues. During mummification, outgrowths of fungal hyphae occur first and most extensively in the intersegmental regions of larvae. Conidia from mutants exhibiting low levels of pathogenicity are either significantly delayed or do not germinate on larval surfaces. When germination does occur, hyphae from such mutants do not penetrate immediately; instead, extensive surface hyphal growth, with or without eventual penetration of the integument, is evident.

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Journal of Invertebrate Pathology

Abstract

References (19)

A mechanism of pathogenicity of Beauveria bassiana on the larvae of the imported fire ant, Solenopis richteri

J. Invertebr. Pathol

Field and laboratory studies of the pathogenicity of the fungus Beauveria bassiana to three genera of mosquitoes

J. Invertebr. Pathol

Laboratory and field studies with Boverin: A mycoinsecticidal preparation of Beauveria bassiana (Bals) Vuill. obtained from the Soviet Union

Environ. Entomol

The formation and the circulation in Galleria of hyphal bodies of entomophthraceous fungi

J. Invertebr. Pathol

Action of enzymatic systems of Beauveria bassiana on the cuticle of the greater wax moth larvae (Galleria melonella)

J. Invertebr. Pathol

Percutaneous infection of Hylobius pales by Metarrhizium anisopliae

J. Invertebr. Pathol

Histological and ultrastructural studies of Beauveria bassiana infection in Leptinotarsa decemlineta larvae during ecdysis

J. Invertebr. Pathol

Fine structure of the fungus, Metarrhizium anisopliae, infecting three species of larval Elateridae (Coleoptera). II. Conidial germ tubes and appressoria

J. Invertebr. Pathol

Fine structure of the fungus Metarrhizium anisopliae infecting three species of larval Elateridae (Coleoptera). III. Penetration of host integument

J. Invertebr. Pathol

Cited by (107)

The tracheal immune system of insects - A blueprint for understanding epithelial immunity

Strategies for sustainable and ecofriendly pest management in Agroecosystem

Seed biopriming with biopesticide: A key to sustainability of agriculture

Microbial biopesticides for sustainable agricultural practices

Role of phytopesticides in sustainable agriculture

Microbial biopesticides: Current status and advancement for sustainable agriculture and environment