Evaluation of the Pathogenicity of Metarhizium taii and Trichoderma afroharzianum on Immature Stages of Bemisia tabaci in Tomato Plants

The whitefly (Bemisia tabaci) (Hemiptera: Aleyrodidae) is a small phytophagous invertebrate of herbaceous plants, shrubs, trees, wild plants, and crops of economic importance. It generates substantial economic losses due to direct damage caused by sap sucking and virus transmission. This work presents referential images of the morphology of B. tabaci and one of its main biological controllers in southern South America, thus serving as a reference for other researchers. In addition, results are presented of studies carried out to evaluate the pathogenicity of two fungal isolates (previously selected in vitro against Sclerotinia sclerotiorum and Botrytis cinerea and plant growth promoters) identified as Metarhizium taii CEP-722 and Trichoderma afroharzianum CEP-754 in immature stages of B. tabaci in tomato plants (Solanum lycopersicum). The trials were conducted under controlled conditions in controlled chambers, ensuring optimal growth conditions for B. tabaci, after morphological prospection, collection, identification, and mass rearing of adults in entomological cages. The results indicate that M. taii CEP-722 caused approximately 30% mortality in the immature stages of B. tabaci, while T. afroharzianum CEP-754 did not increase mortality under the experimental conditions. This study provides new knowledge on the potential of M. taii as a biological control agent against B. tabaci, offering a promising alternative in integrated pest management strategies. The results with T. afroharzianum suggest that further methodologies or combinations should be explored to improve its efficacy.