Formulaciones Micro Encapsuladas de Metarhizium anisopliae1 Contra el Gusano Tabacalero

The bioinsecticide effect of two microencapsulated formulations of the entomopathogenic fungus Metarhizium anisopliae was evaluated on first-instar larvae of tobacco budworm, Chloridea virescens, a recurring pest of tomato and chickpea at Sinaloa, Mexico. Each microencapsulated contained M. anisopliae at 1×10⁸conidia/ml, MDF1 based on maltodextrin at 10%, GBF2 with bovine gelatin at 7%. Macrocystis pyrifera algal extract at 2% was added to each formulation as adjuvant. Fungus at 1×10⁸conidia/ml and distilled water was used as a check. The MDF1 microencapsulation measured 2 to 18 microns, had 2.95% of moisture, 87% of adherence, 85% of solubility, and conidia release time of 15 minutes; GBF2 measured 1 to 10 microns and had 3.1% of moisture, 79% of adherence, 82% of solubility, and release time of 28 minutes. The mortality of C. virescens was 68% in MDF1 and 54% in GBF2, and their lethal times were 4.5 and 4.9 days. M. pyrifera extract allowed release and germination of the conidia that adhere better to insect cuticle, making them more effective for control of C. virescens.