α-Amylase Activity of Rhyzopertha dominica (Coleoptera: Bostrichidae) Reared on Several Wheat Varieties and Its Inhibition with Kernel Extracts

• Published in: Journal of economic entomology 2006-12, Vol.99 (6), p.2146-2150
• Main Authors: Cinco-Moroyoqui, Francisco J., Rosas-Burgos, Ema C., Borboa-Flores, Jesús, Cortez-Rocha, Mario O.
• Format: Article
• Language: English
• Subjects: alpha-amylase; alpha-Amylases - analysis; alpha-Amylases - antagonists & inhibitors; amylase inhibitors; Animals; Biological and medical sciences; Coleoptera - growth & development; Coleoptera - physiology; Control; Diet; enzyme activity; enzyme inhibition; enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Generalities; insect reproduction; Insecta; Invertebrates; isoamylases; isozymes; Phytopathology. Animal pests. Plant and forest protection; PLANT RESISTANCE; Protozoa. Invertebrates; R. dominica isoamylases; Reproduction; Rhyzopertha dominica; seed extracts; Seeds - chemistry; storage insects; Triticum; varietal resistance; varieties; wheat; wheat resistance
• ISSN: 0022-0493; 1938-291X; 0022-0493
• DOI: 10.1603/0022-0493-99.6.2146

Total progeny of Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) reared on 10 wheat, Triticum aestivum L., varieties was evaluated. Higher amylase activities were detected in populations with few individuals, whereas the opposite was observed in higher populations. As protein ingested increased, reproductive success increased. However, consumption of wheat protein was inversely correlated with amylase activity levels (r = −0.66). Amylase activity in homogenates of R. dominica populations showed variable inhibition by wheat extracts prepared from wheat varieties on which they were reared. Insect populations with lowest amylase activities were inhibited more by wheat extracts than those with higher amylase activity (r = −0.77). An electrophoretic analysis revealed four phenotypes showing combinations of three isoamylases (Rm 0.70, 0.79, and 0.90) in different populations of R. dominica. Some of the insect progeny that emerged from resistant wheat varieties contained the three isoamylases, whereas progeny that emerged from the most susceptible varieties showed reduced activity of isoamylases 0.70 or 0.90. These results suggest that the α-amylase activity levels and the composition of isoamylases in R. dominica populations are modulated by diet and that the α-amylase inhibitory activity of the wheat kernels influences these variations.