The Effect of Beauveria bassiana on Parasite Fauna of Organic Habanero Pepper in Quintana Roo, Mexico

In Quintana Roo, Mexico, partial losses of vegetable crops due to insects are seriously limiting satisfactory output.  Using native strains of entomopathogenic fungi can contribute to controlling some of the most harmful insects. In a trial carried out in 2011 and 2012 in central Quintana Roo, we evaluated the effect of a native strain of B. bassiana (1.1 X10¹⁰ spores/mL) on the insect fauna associated with green habanero pepper under organic management.  With the goal of evaluating the effect of the applied fungus on the present parasitic fauna in 2011, 1.3 g·L^-1 of fungus (mixed with rice) of water were applied to 12 blocks in a 0.2-ha habanero pepper field under organic management. Randomized blocks of 5 m² and 10 pepper plants each were monitored. Systematic collections of all observed insects were performed every three days. Application started 30 days after transplanting and was carried out every 20 days.  All collected insects were placed in a moist chamber for 15 days. They were observed every 48 hours to record the number of insects killed by the fungus. Twenty-five percent (25%) of collected insects developed B. bassiana; the most abundant orders were Hemiptera (11% of infected insects), Coleoptera (6%), and Orthoptera (5%). All were phytophagous species.  In 2012, the effect of varying doses of B. bassiana on the most harmful parasites was compared. Doses of 5, 10.5, and 14 g·L^-1 of water were applied to four blocks each. Selective collection involved Bemisia tabaci, Erythrogonia spp., and Anthonomus eugenii. Block design and crop management were the same as in 2011.  Thirty percent (30%) of all collected parasites were killed by B. bassiana. The significantly most efficient treatment was observed using a dose of 10.5 g·L^-1 fungus but control was only satisfactory for Erythrogonia spp.  Applying native strains of B. bassiana is a highly efficient measure to control Erytrhogonia spp, a harmful parasite of the habanero pepper.  Satisfactory control requires a dose of 10.5 g·L^-1 fungus; the commonly used dose of 1.3 g·L^-1 is not recommendable. As for controlling B. tabaci and A. eugenii with the entomopathogenic fungus, further research is necessary.