Effects of the fungus Lecanicillium lecanii on survival and reproduction of the aphid Schizaphis graminum

Abstract

This study investigated the effects of a strain of the fungus Lecanicillium lecanii (Zimm.) Zare and Gams (Hypocreales: Ascomycota) on the aphid Schizaphis graminum (Rondani) (Hemiptera: Aphididae). The fungus was administered to fourth instar nymphs and to alate and apterous adult morphs as a ground rice-kernel formulation. This study showed that L. lecanii formulation affected the survival of the aphids and interacted differently with the studied morphs, the Lethal Time values being lower for alate compared to apterous morphs and nymphs. The treatment also caused a significant reduction in the fecundity of the three treated aphid groups. Histological analysis revealed that the hyphae invaded the host hemocoel of a limited number of alate and apterous morphs: the fungus only entered through the spiracles. Scanning Electron Microscope observations revealed that L. lecanii adhered to the body surface of both adults and nymphs without differentiation. In conclusion, the present study suggests that this strain might be a good candidate for a programme of biological control of S. graminum and other aphid species.

Susceptibility of Myzus persicae, Brevicoryne brassicae and Nasonovia ribisnigri to Fungal Biopesticides in Laboratory and Field Experiments

“…Spatafora, Kepler & B. Shrestha, comb. nov. (formerly Lecanicillium lecanii [32]) infection in wheat aphid Schizaphis graminum Rondani, 1852 [73], and in B. bassiana infection in N. ribisnigri [74].…”

The Herbivore-Induced Plant Volatiles Methyl Salicylate and Menthol Positively affect Growth and Pathogenicity of Entomopathogenic Fungi

“…Conidia were harvested by scraping the surface of sporulating cultures with an inoculating loop. Conidial suspension adjusted at the concentration of 1 × 10 8 conidia·ml −1 was prepared with sterile water containing 0.05% Triton X-8045. Ten microliters of the fungal suspension were transferred to the center of round cellophane membranes (80 mm diameter) which covered the surface of the Czapek’s medium in a Petri dish (90 mm diameter).…”

Volatiles from Plants Induced by Multiple Aphid Attacks Promote Conidial Performance of Lecanicillium lecanii

“…Conidia of L . lecanii were cultured with modified Czapek’s medium for 14 d [ 34 ], and then the conidia were scraped using an inoculating loop in sterile water containing 0.05% Triton X-80 [ 43 ]. The conidial suspension was filtered by cotton in a 20-ml syringe to remove the hyphal debris and then diluted to 5 × 10 7 conidia·mL -1 by using a Neubauer hemocytometer with a sterile solution of 0.1% Tween-80 for infection.…”