Effects of Abiotic Factors and Host Preference on the Biology of the Oriental Cabbage Webworm, Hellula undalis Fabricius (Lepidoptera: Pyralidae)

Because of the importance of Hellula undalis (Lepidoptera: Pyralidae) as a serious pest of crucifers in Iran and inadequate information, this study was conducted to investigate its biology under laboratory and greenhouse conditions on different host plants during the years 2007-2008. The result showed that the maximum percentage of larval mortality and survival were observed at 15±0.5°C and 25±0.5°C. respectively, at each given temperature, different relative humidity produced a significant effect on the mortality while the influence of same relative humidity at different temperatures was not significant. At 20±0.5°C, pupae were heavier than 25±0.5°C. The greenhouse study showed that mean larval period on cabbage and rapa was significantly longer and shorter than on the other hosts, respectively. The pupal weight differed significantly at 22.5°C between chou moellier and other host plants. At 24.3°C, a significant pupal weight was found between rapa and cauliflower in comparison to cabbage and chou moellier.