Population Dynamics of Aphid, Myzus persicae (Sulz.) and Its Natural Enemies on Cumin, Cuminum cyminum Linn. in Relation to Abiotic Factors

By : R.P. Samota, K.C. Kumawat, R.G. Samota

Page No: 25-28

Abstract
The population of aphid, Myzus persicae (Sulz.) on cumin, Cuminum cyminum Linn. appeared on 8th January 2012, i.e., 2nd meteorological week (15.87 aphids/ three umbels) and reached its peak on 5th February 2012 (6th meteorological week, SMW), when maximum temperature, minimum temperature and relative humidity was 21.7°C, 4.1°C and 60 per cent, respectively. The population declined gradually, thereafter. Among natural enemies, the population of ladybird beetles, Coccinella septempunctata was found high in number. The correlation coefficient worked out revealed significant negative correlation (r= -0.89) between the aphid population and maximum temperature at 1 per cent level of significance. The minimum temperature and relative humidity showed non-significant correlation with the aphid population at 5 per cent level of significance. With regards to the ladybird beetles, Coccinella septumpunctata, the effect at the maximum temperature revealed significant negative correlation (r = - 0.64). There was a significant positive correlation (r= 0.85) between mean population of aphid and C. septempunctata. It was evident that the population of C. septempunctata increased with the food availability (aphids).

Authors :
R.P. Samota, K.C. Kumawat and R.G. Samota : Department of Agricultural Entomology, S.K.N. College of Agriculture (SKNAU), Jobner-303 329, Rajasthan.