The biological and physiological responses of Leptinotarsa decemlineata Say (Col. Chrysomelidae) to different potato cultivars.

BACKGROUND: The use of pest-resistant or less susceptible plant varieties is of great importance for integrated pest management programs. This study was conducted to evaluate the resistance of seven potato cultivars to a major pest, namely the Colorado potato beetle (CPB), by measuring its bio-physiological aspects. RESULTS: The longest developmental time and the lowest survival rate of CPB were detected on cultivar 'Manitou.' Although the larvae fed voraciously, the food conversion efficiency was the lowest on this cultivar leading to the lowest relative growth rate. Furthermore, larvae reared on Manitou had the lowest total protease activity and specific activity values of cathepsin B compared to the larvae reared on other cultivars. Additionally, the cluster analysis showed that the Manitou cultivar was the least suitable (partially resistant) CPB. Moreover, the results indicated that the protein content was the lowest in the Manitou cultivar; conversely, this cultivar was rich in polyphenol and flavonoid compared to Agria and Santae cultivars. CONCLUSION: The overall results in this study indicated that the Manitou cultivar might be a good candidate to be incorporated into integrated pest management programs. © 2022 Society of Chemical Industry.

Identification of a putative antifreeze protein gene that is highly expressed during preparation for winter in the sunn pest, Eurygaster maura.

A cDNA library generated from the fat body of field-collected, diapausing adults of the sunn pest, Eurygaster maura revealed the presence of a transcript that encodes a protein that shares the distinct physiochemical and structural features of an insect antifreeze protein. The transcript, which is most abundant in the midgut, accumulates in adults as they leave the fields in late summer and migrate to surrounding mountainous areas to overwinter. Transcript abundance again declines when adults return to the fields the following spring. This winter pattern of abundance suggests that this protein may be critical for winter survival in the cold regions where the bug enters its obligatory diapause.