Efficacy of entomopathogenic fungal formulations against Elasmolomus pallens (Dallas) (Hemiptera: Rhyparochromidae) and their extracellular enzymatic activities
Document Type
Article
Publication Date
9-1-2022
Abstract
Elasmolomus pallens are post-harvest insect pests of peanuts that are becoming resistant to chemical insecticides. In this, we study evaluated the effect of conidial formulations on entomopathogenic fungi against E. pallens to reduce the adverse effects. Fungal conidia were formulated and applied on sterile filter papers at varying concentrations (1 x 10(4)-1 x 10(8) conidia mL(-1)) inside plastic containers. The test insects were exposed and maintained in a relative humidity of 80 +/- 10% for 10 d at room temperature (25 +/- 2 degrees C). Mortality was recorded every 24 h. Dose-response bioassay (LC50 and LC90) values for Aspergillus flavus formulated in oil were 1.95 x 10(6) and 3.66 x 10(9) conidia/mL, whereas formulations in Tween 80 had 9.36 x 10(7) and 6.50 x 10(9) conidia/mL. However, oil-formulated Metarhizium anisopliae had 3.92 x 10(6) and 2.57 x 10(8) conidia/mL, with 6.85 x 10(6) and 5.37 x 10(8), for formulations in Tween 80. A. flavus had LT50 values of 3.3 and 6.6 days, whereas M. anisopliae had LT50 values of 3.6 and 5.7 d. Maximum protease, chitinase, and lipase activities of 2.51, 0.98, and 3.22 U/mL, respectively, were recorded for A. flavus, whereas values of 2.43, 0.93, and 3.46 were recorded for M. anisopliae. The investigated pathogens demonstrate potential against E. pallens; therefore, their applicability under field conditions requires further investigation.
Keywords
Biological control, Bioassay, Enzyme, Entomopathogenic fungi, Oil formulation, Seed bug
Divisions
Science
Funders
University of Malaya Center of Research Grant Management (PPGP) [PG343 2016A]
Publication Title
Toxins
Volume
14
Issue
9
Publisher
MDPI
Publisher Location
ST ALBAN-ANLAGE 66, CH-4052 BASEL, SWITZERLAND