SELECTION OF METARHIZIUM ANISOPLIAE AND BEAUVERIA BASSIANA ISOLATES TO CONTROL ASYNONYCHUS CERVINUS AND OTIORHYNCHUS SULCATUS (COLEOPTERA: CURCULIONIDAE) ATTACKING RASPBERRIES IN CHILE

Two of the main insect pests of raspberries in Chile are the two curculionids: Asynonychus cervinus (Fuller rose beetle) and Otiorhynchus sulcatus (Black vine weevil). At the larval stage they feed on the roots of the crop causing an important economic damage.
We carried out a screening of Beauveria bassiana and Metarhizium anisopliae isolates to determine their pathogenicity on A. cervinus and O. sulcatus, both at adult and larval stage.
Thirty seven B. bassiana isolates were evaluated on A. cervinus larvae and 24 M. anisopliae isolates on O. sulcatus adult and larvae.
The selected isolates were tested by dipping individuals of each specie in suspensions of different conidia concentrations (0 to 10⁸ conidia ml^-1). Mortality rates, Lethal Concentrations (LC₅₀ and LC₉₀) and food intake were determined.
Different levels of pathogenicity among the isolates were detected.
The most aggressive B. bassiana isolates for A. cervinus were Qu-B179, Qu-B299, Qu-B314 and Qu-B323. For O. sulcatus adults, the most virulent M. anisopliae isolates were Qu-M151b, Qu-M232 and Qu-M271. The best isolate to control O. sulcatus was Q-M151b, with a LC₅₀ of 1×10^6.53 and LC₉₀ of 1×10^7.82 conidia ml^-1. Adult A. cervinus leaf consumption after B. bassiana inoculation was reduced up to 70% in 35 days.
The LC₅₀ and LC₉₀ calculated for A. cervinus were 1×10^4.7 and 1×10^8.3 conidia ml^-1, respectively.

IX International Rubus and Ribes Symposium

M. Gerding, M. Rodríguez, A. France, M. Gerding-González

biological control, curculionids, entomopathogenic fungus, biopesticide

https://doi.org/10.17660/ActaHortic.2008.777.59