A laboratory assessment of the potential of the entomopathogenic fungi Beauveria bassiana (Beauvarin) to control Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) and Sitophilus granarius (L.) (Coleoptera: Curculionidae)

Abstract

This research was carried out to evaluate the suppressive efficacy of entomopathogenic fungi Beauveria bassiana against adults of Callosobruchus maculatus (F.) and Sitophilus granarius (L.) on stored grains in darkness (27±2°C and 65±5% RH). The insects were inoculated by following immersion in five aqueous suspensions with concentrations determined with preliminary tests and compared with untreated wheat and cowpea as control. Probit analysis showed that the lowest LT 50 values in suspensions with highest concentrations (2.3 × 10 7 conidia ml -1 ) were 6.63 and 10.45 days for C. maculatus and S. granarius, respectively. On the other hand, the LC 50 values on day 9 post-treatment were 3.17 × 10 6 and 6.08 × 10 7 con.ml -1 for C. maculatus and S. granarius, respectively. Comparison of Lc 50 , LT 50 values and mortalities indicated that in both assays, B. bassiana was consistently more virulent for C. maculatus than S. granarius. The overall results showed that these two pests were controlled successfully with entomopathogenic fungi Beauveria bassiana.

Preliminary Tests Regarding Fumigant Effect of Volatile Oils Obtained from Medicinal Plants

“…Essential oils have shown insecticidal activity against field crop pests (Verma et al, 2000). Among the pathogens, the entomopathogenic fungi have been most studied for stored product insect control (Kavallieratos et al, 2006;Athanassiou and Steenberg, 2007;Kavallieratos et al, 2008;Golnaz et al, 2011). Isolates of entomopathogenic fungus Beauveria sp.…”