Pathogenicity on Erinnyis ello (Lepidoptera: Sphingidae) in laboratory conditions of entomopathogen fungus collected in comercial crops cassava Manihot esculenta in Cauca Valley,Colombia

Infected insects with fungus were collected in cassava crops in the Cauca Valley. In the laboratory, the fungus Beauveria bassiana (B.b.9601 and B.b.9602) and Aspergillus (Asp.9601) were isolated, purified and identified. These native isolates together with one of Metarhizium anisopliae (M.a.9206), received from CENICAFE, were evaluated on larvae of E. ello. The methodology to select the more pathogenic isolates and the best method of inoculation between aspersion on larvae, leaf and larvae-leaf was determined. The most susceptible larval Instar of the selected isolate was also determined to establish the LD50. The individual separation of the treated insects in cardboard boxes with plastic sheet of 14 x 11.5 x 5 cm with cap was the most adequate methodology to do pathogenic tests on E. Ello and was denominated "Experimental Unit Múnera De Los Rios". B.b.9601 was the most pathogenic isolate causing mortality between 77.5% and 87.5% presenting significant differences (P<0.05) compared to the other isolates; M.a 9206 caused mortalities no greater than 67.9%; B.b.9602 caused a lower mortality of 16.1% and Asp.9601 wasn't pathogenic. There was no significant difference between inoculation methods (P<0.05); choosing aspersion to larval-leaf to be most similar to field application. Instar III showed greatest susceptibility to B.b.9601. The LD₅₀ of B.b.9601 was 1x10^4.8018 viable conidias ml⁻¹ with confidence limits between 1x10^0.3523 and 1x10^7.4120. B.b.960 sprinkled on fifth instar larvae produced a mortality of 40%, the survivors showed a normal oviposition and eggs with high viability. B.b.9601 inoculated on eggs doesn't caused considerably mortality. The aspersion of a mixture of B.b.9601 and M.a 9206 caused 90% mortality in III ínstar larvae.