BIOLOGICAL CONTROL Ð MICROBIALS Pathogenicity of Entomopathogenic Fungi Metarhizium anisopliae and Beauveria bassiana (Hypocreales: Clavicipitaceae) Isolates to the Adult Pea Leafminer (Diptera: Agromyzidae) and Prospects of an Autoinoculation Device for Infection in the Field

Seventeen isolates ofMetarhizium anisopliae (Metschnikoff) Sorokin and three isolates of Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) were evaluated for their pathogenicity to the adult pea leafminer, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae), in the laboratory. Flies were contaminated with dry conidia through a velvet material wrapped around the inner sideof a cylindrical plastic tube.All the isolateswerepathogenic to thepea leafminer, causingmortality between 40 and 100% at 5 d after exposure. The lethal time for 50%mortality (LT50) ranged from2.6 to 5.4 d,whereas theLT90 values variedbetween3.2 and9.1ddependingon the isolate. An autoinoculation device was evaluated in cage Þeld experiments using only one of the virulent isolates, M. anisopliae ICIPE 20. The device was loaded with 2Ð3 g of dry conidia. Mortality of up to 100%was observed in ßies captured from fungus-treated cages held under laboratory conditions. The average number of spores picked up by a single ßy visiting the device increased with days after inoculation. One day after the inoculation, adults picked up an average of 4.1 0.7 10 conidia and 39.6 4.0 10 conidia 5 d after inoculation. Depending on the sampling date, the LT50 varied between 1.8 and 3.4 d. Results indicate that some isolates of B. bassiana and M. anisopliae are highly pathogenic to L. huidobrensis, suggesting a potential for their use in the control of this pest. They also suggest the possibility of L. huidobrensis suppression with fungi using an autoinoculation device.