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

• Published in: Pest management science Vol. 74; no. 11; pp. 2608 - 2617
• Main Authors: Oliveira, Andresa CB, Wanderley‐Teixeira, Valeria, Silva, Cristiane TS, Teixeira, Álvaro AC, Siqueira, Herbert AA, Cruz, Glauciane S, Neto, Clovis J C Lapa, Lima, Amanda LR, Correia, Maria TS
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.11.2018; Wiley Subscription Services, Inc
• Subjects: Acetylgalactosamine - metabolism; Animals; Bacillus thuringiensis - chemistry; Carbohydrate Metabolism; Digestive System - anatomy & histology; Digestive System Physiological Phenomena; Formulations; Glucose - metabolism; Glycogen; Glycosylation; Histochemistry; Histology; Histopathology; Insecticide Resistance; Insecticides; Insecticides - pharmacology; Insects; Intestine; Labeling; Larva - growth & development; Larva - metabolism; Larva - physiology; Lectins; Lectins - chemistry; Mannose; Mannose - metabolism; Microscopy; Midgut; morphology; Moths - growth & development; Moths - microbiology; Moths - physiology; N‐acetylgalactosamine (GalNAc); Optical microscopy; Organic chemistry; Peroxidase; Population studies; Populations; Proteins; Receptors; Soybeans; Toxins; Tuta absoluta; N-acetylgalactosamine (GalNAc); Histopathology; morphology; lectins
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.5051

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. absoluta populations to assess susceptibility to the insecticides Bt fomulations. The histochemistry analysis used Periodic Acid–Schiff for glycogen and Ponceau Xylidine for total proteins. The presence of glucose/mannose and N‐acetylgalactosamine (GalNAc) was analyzed using specific lectins. One susceptible and one tolerant population were used in the study; insects were exposed to the insecticide concentrations recommended by the manufacturers. The midgut was collected after an interval of 20 min and analyzed using optical microscopy. RESULTS Bt fomulation interferes with the glycogen content, whereas XenTari® interferes with the protein content, irrespective of the level of susceptibility. High expression of GalNAc residues was observed using soybean lectin labeling, indicating a direct relationship between the glycosylation pattern and susceptibility to Bt fomulation in the Pelotas population. CONCLUSION The use of Bt fomulation caused greater alterations in the larval intestinal histophysiology compared to the use of XenTari®. © 2018 Society of Chemical Industry This study evaluated membrane receptors using peroxidase‐labeled lectins and the midgut histochemistry of Tuta absoluta populations in order to assess susceptibility to the insecticides Bt fomulations.