According to the NCERT text, Bacillus thuringiensis is used to control butterfly caterpillars . Trichoderma species are effective biocontrol agents of several plant pathogens . Nucleopolyhedrovirus is used as a biological control agent against insects and other arthropods . Xanthomonas campestris is typically a plant pathogen (causing diseases like black rot in crucifers), not a biopesticide.