Antixenosis by a resistant < em > Musa < /em > cultivar to stem borer < em > Odoiporus longicollis < /em > attack and expression of microsomal α-amylase by the pest

J Biosci. 2023;48:6.ABSTRACTBanana pseudo-stem weevil (BPW) Odoiporus longicollis Olivier is a serious pest of Musa cultivars which completes its lifecycle as an internal parasite in the pseudo-stem of susceptible host plants. The larval stage of BPW is destructive and difficult to control as larvae are endophytic. Plantains (bananas), resistant to infestation by BPW, exhibited antixenosis against the larvae. Experimental maintenance of the larvae for 4 days in the live pseudo-stem of the resistant plantain resulted in the disruption of carbohydrate metabolism and imbalance of protein-free amino acid turnover. The pseudo-stem possesses three larvicides: stigmasterol-3-O-glucoside (SOG), sulfoquinovosyl diacylglycerol (SQDG), and betulinic acid (BA). Larvicides cause significant elevation in hemolymph protein and reduction in total free amino acids. Larvae treated with larvicides showed elevated activities of hexokinase, trehalase, and lactic acid dehydrogenase, which resulted in significant decrease of glucose and trehalose but sharp increase of lactic acid. Also, inhibition in the activity of glycogen phosphorylase caused significant increase of fat body glycogen in affected larvae. At LD20 concentration, toxicities by SOG, SQDG, and BA were similar but antixenosis by the resistant host plant was more severe due to the simultaneous action of three larvicides present in the resistant, live pseudo-stem. Disruption of carbohydrate metabolism and imbalance of protein-amino acid ...
Source: Journal of Biosciences - Category: Biomedical Science Authors: Source Type: research