Effect of temperature and relative humidity on the development of Sitophilus oryzae L. (Coleoptera: Curculionidae) reared on noodles

Abstract

This study aimed to investigate the development and fecundity of Sitophilus oryzae L. (Coleoptera: Curculionidae) at 20–32 °C and 55%–75% of relative humidity (RH) in dried noodles obtained from wheat flour using different processing precision. The optimal growth temperature of S. oryzae fed on N1 noodles made of high-precision wheat flour was 24 °C. When the temperature of S. oryzae fed on N2 noodles made with low precision wheat flour dropped to 20 °C, this pest showed certain growth and reproduction ability. A lower development rate of S. oryzae was observed as a result of decreasing in relative humidity. At 55% RH, S. oryzae did not survive at all temperatures tested. There were significant differences in the development of S. oryzae in noodles from different wheat flours. The S. oryzae fed on N1 noodles had a shorter development period, higher fecundity and survival rate than those on N2 noodles. Additionally, the population trend index increased from 0.93 to 2047.35. This work showed that noodles made from high-precision wheat flour could be more susceptible to insects. Our results demonstrated that the ambient temperature above 28 °C and RH below 55% were conducive to the prevention of S. oryzae in dried noodles.