Biological control of lepidopterans with entomopathogens.
The use and research with baculovirus and Bacillus thuringiensis (Bt) based biopesticides have increased since 2012/13, when Helicoverpa armigera was officially detected in Brazil. Embrapa Maize and Sorghum Research Center has collection with more than 4.600 strains of Bt and more than a 100 baculovirus isolates, collected from different regions of Brazil since 1984. Many of these insect pathogens have been tested against: Spodoptera frugiperda, S. cosmioides, S. eridania, Helicoverpa zea, H. armigera, Chrysodeixis includens, Dichelops sp. and Diatraea saccharalis. Some NPV baculovirus have been developed as biopesticides (WP-wetable powder) to control the fall armyworm, the soybean caterpillar and the cotton bollworm. Baculovirus spodoptera (isolate 6NR) does note cause the liquefaction of the integument, an important factor in a large scale production system. Baculoviruses isolated from H. armigera, and identified as Hear NPV, were formulated as WP. In Bt strains many cry genes and Vip genes were found. These Bt strains were tested against caterpillars and sucking bugs. Some Bt isolates also have been developed as biological pesticides to control fall armyworm, soybean looper and cotton bollworm. Some biopesticides were registered to be used in the field.