Massive Production and Preformulation of Metarhizium Spp. for Llanera Locust Biological Control

With the purpose to standarize the conditions to obtain a biopesticide prototipe useful to the control of the llanera locust Rhammatocerus schistocercoides were established the conditions for Metarhizium spp. massive production, consisting in two methods for fungus inoculation of a sustrate based in steril humid rice contained in high density polietylene bags which were incubated for 15 days at 25°C after inoculation. One methods consisted in the utilization of a liquid preinoculum grown for two days and the other method consisted in the direct inoculation of the rice. In both cases a suspension of 10⁹ spores/ml of the fungus was used as inoculum. The highest level of sporulation was obtained with the last method and was expresed as 30 x 10⁸ u.f.c./g for M. anisopliae and 70 x 10¹³ u.f.c./g for M. flavoviridae. Spores were separated from the substrate and obtained biomass was dried for 24 hours at 25°C. Subsecuently the compatibility between spores and different individual excipients was deteminated and an adherent, a vegetal oil and two solar filters (CBUV01 and CBUV02) were selected in order to obtain a product in powder. This product consisted in spores pelletized with chemical sunscreens and was designed to be reconstituted in a oil in water emulsion (O/W) consisting in sunflower oil, Tween 80, Span 80 and water. In order to determinate the effect of UV radiation against the product bare spores and pelletized spores were exposed to ultraviolet radiation under laboratory conditions at a laboratory radiation of 253,7 nm and under field conditions solar direct exposition at Puerto López, Meta. we demostrated in both cases that excipients used to pelletize spores protected effectively the fungus against ultraviolet radiation adverse effects. Moreover, these excipients did not affect the biocontrol activity of Metarhizium spp. against llanera locust under laboratory conditions.