Abstract
The insecticidal virulence of various entomopathogenic fungal isolates retrieved from soil samples was tested on adults of the granary weevil Sitophilus granarius (L.) (Coleoptera: Curculionidae). Bioassays were carried out in the laboratory where experimental adults were sprayed with 1 mL of conidial suspension (108 conidia/mL) from each isolate. Mortality was recorded at 7, 14, and 21 days after exposure. Mean mortality, mean lethal time, survival, and hazard effect were estimated for each isolate. Two isolates of Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae), one isolate of Aspergillus insuetus (Bainier) Thom & Church (Eurotiales: Trichocomaceae) and Metarhizium anisopliae (Metschinkoff) Sorokin (Hypocreales: Clavicipitaceae) resulted in the highest mortality (97–100%). The isolates with both the highest hazard effect and the lowest survival rate were Aspergillus sp. and M. anisopliae. Our results indicate that entomopathogenic fungi have the potential to become a very useful tool in reducing chemical applications in storage facilities.
Highlights
Insects are major agricultural post-harvest pests causing serious damage to the quality, the quantity, and the commercial and agronomic value of various stored products [1]
As part of our project on the development and application of Entomopathogenic Fungi (EF) in the integrated pest management (IPM) of stored product pests, we investigated the potential of 27 fungal isolates as biological control agents against the granary weevil S. granarius, a notorious pest of stored grain with worldwide distribution [6]
Mycelial and conidial growth on cadavers suggested that recorded mortality was pathogen related
Summary
Insects are major agricultural post-harvest pests causing serious damage to the quality, the quantity, and the commercial and agronomic value of various stored products [1]. Nowadays, stored product pest control is based mainly on the use of two broad categories of insecticides: residual insecticides and fumigants. Chemical strategies involve direct application of contact insecticides to grain and surface treatments on bag stacks, storage structures providing protection from invading pests, and fumigants used to control pests that are already infesting stored grain [2,3]. Sitophilus granarius (L.) (Coleoptera: Curculionidae) belongs to the most severe storage pests of raw cereals in the world and its control consists mainly in the application of fumigants and residual insecticides [6]. The long-term use of these synthetic chemicals holds the risk that inadequate treatments could lead to resistance in pest populations, a fact that has already been reported for Agriculture 2019, 9, 222; doi:10.3390/agriculture9100222 www.mdpi.com/journal/agriculture
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
