Field-evolved resistance in Phthorimaea absoluta to abamectin: genetic foundations, female-linked traits, and cross-resistance pattern.

Background: Phthorimaea absoluta (Meyrick) (Lepidoptera: Gelechiidae) poses a significant challenge in tomato cultivation owing to its increasing resistance to various insecticide classes. This study aimed to characterize the resistance of a field-collected P. absoluta population to abamectin, focusing on its genetic aspects and cross-resistance with other chemical groups, and monitoring the frequency of resistance in other populations.

Labeling membrane receptors with lectins and evaluation of the midgut histochemistry of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) populations with different levels of susceptibility to formulated Bt.

Background: Studies show that insects can adapt to the toxins of Bacillus thuringiensis under field and laboratory conditions through the development of resistance to the bacterium and its formulations. This has been demonstrated in the failure to control Tuta absoluta populations in Brazil. This study evaluated membrane receptors using peroxidase-labeled lectins and the midgut histochemistry of T.