Effect of Varying Temperature on the Development and Predation of Coccinella transversalis F. (Coleoptera: Coccinellidae) on Lipaphis erysimi (Kaltenbach)
2008
ʻAlī, Arshad | Rizvi, Parvez Qamar
A laboratory study was conducted to determine the developmental and predatory response of Coccinella transversalis on mustard aphid, Lipaphis erysimi (Kaltenbach) at three constant temperatures viz., 18, 24 and 28±1ºC coupled with 65±5% R.H. and 12 hr L:12 hr D for each. All the developmental stages (immature and adult) were significantly longer at 18±1ºC followed by 24±1ºC and 28±1ºC. The survival of individuals of all stages was more at 24±1ºC in comparison to 18 and 28±1ºC. The mortality parameters (per cent mortality and k-value) of different developmental stages were recorded maximum at 28±1ºC and minimum at 24±1ºC. Varying temperature did also show significant difference on predatory response of C. transversalis. Both the stages (grub and adult) devoured maximum aphids at 28±1ºC as compared to 18 and 24±1ºC. The last grub stage (Grub 4) devoured maximum aphids as compared to other grub stages. The feeding propensity of female was more than male at all the temperatures. The temperature was negatively correlated with development, while positive with predation of C. transversalis.
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