The effects of supplementation of high protease activity wheat (Triticum aestivum) flour due to bug (Eurygaster spp.) damage on characteristics of wheat flour extrudates were investigated. Different proportions of high protease activity flour (HPAF) were blended with wheat flour (0, 10, 20, 30 and 40%) and extruded with a twin-screw Brabender laboratory extruder (Model CTSE-V) at two different barrel temperatures (140 degrees C and 160 degrees C). The obtained extrudates were tested for extrusion quality parameters. Significant differences were observed between two barrel temperatures (140 degrees C and 160'C) in terms of water absorption index (WAI), specific mechanical energy (SME), bulk density (BD) and color (redness) values of the extrudates (p < 0.05). Statistical analysis showed that addition of HPAF had significant effect on SME, WAI and WSI (water solubility index) values of extruded samples at 140 degrees C. At higher process temperatures (160 degrees C), SME, color, WAI and WSI values of the extrudates were significantly affected by the addition levels of HPAF. At both process temperatures, a significant decrease and a significant increase were observed in BD and ER (expansion ratio) values of the extrudates, respectively. These results suggested HPAF had positive effects on some quality parameters (BD, ER, WAI and WSI) of the extrudates in the proportions examined.