Larvicidal activity, route of interaction and ultrastructural changes in Aedes aegypti exposed to entomopathogenic fungi.

Larvicidal activity, route of interaction and ultrastructural changes in Aedes aegypti exposed to entomopathogenic fungi. Acta Trop. 2020 Nov 11;:105732 Authors: de Oliveira Barbosa Bitencourt R, Reis Dos Santos Mallet J, Mesquita E, Silva Gôlo P, Fiorotti J, Rita Elias Pinheiro Bittencourt V, Guedes Pontes E, da Costa Angelo I Abstract Blastospores or conidia (formulated or not) of entomopathogenic fungi were assessed against Aedes aegypti larvae. Larvae (L2) were exposed to 105, 106, 107, and 108 propagules mL-1 water suspension. Mineral oil at 0.1%, 0.5%, or 1.0% (v/v) was employed to observe the effect on larval survival. The 0.1% mineral oil did not affect larval survival. Accordingly, 107 propagules mL-1 and 0.1% mineral oil were used to prepare all fungal emulsions. The fungal suspension or formulation was prepared as follows: 107 propagules mL-1 on 0.03% TweenⓇ 80 (v/v) aqueous solution or 107 propagules mL-1 on 0.03% TweenⓇ 80 plus 0.1% mineral oil; larval survival rates were evaluated for 7 days, and median survival time (S50) was also determined. The presence of fungi in larvae was examined both histologically and by scanning electron microscopy 24 h or 48 h after exposure. To evaluate the larval growth, larvae were exposed to 107 propagules mL-1 for 48 hours and their length measured using a digital caliper. Here, propagules had similar results in reducing the larvae survival rate and time. The treatment with Beauver...
Source: Acta Tropica - Category: Infectious Diseases Authors: Tags: Acta Trop Source Type: research