Biological characteristics of the egg-larval parasitoid Chelonus oculator (Fabricius, 1775) (Hymenoptera: Braconidae) on the potato tuber moth Phthorimaea operculella (Zeller, 1873) (Lepidoptera: Gelechiidae) at different temperatures

Abstract

This study was conducted to determine some biological properties of the potato tuber moth Phthorimaea operculella, a new host of the egg-larval parasitoid Chelonus oculator at different temperatures. The emergence rate, development time, longevity, adult weight, and sex ratio of C. oculator were assessed at three different temperature levels (20±1 ºC, 25±1 ºC, 30±1 ºC), 65±5% humidity and 16:8 light: dark conditions. Forty potato tuber moth eggs, aged 0-24 hours, adhered to the filter papers, were placed into the tubes, and presented to the parasitoids for parasitization for a day. At the end of this period, the parasitized eggs were allowed to develop at the specified temperatures. The study found the highest emergence rate was found at 30 °C, with 20.5%. The longest development period occurred at 20 °C, determined as 49.00±2.00 days in females and 52.27±1.64 days in males. The longest longevity of the parasitoid was found to be 41.71±2.29 and 45.73±3.75 days in males and females, respectively. The highest adult weight was observed at 25 °C for both males and females. The sex ratio was found to be in favor of males as the temperature decreased. It is thought that these results can be used for the biological control of potato tuber moth in the field and storage conditions for release studies.