author(s)
Arjun Panwar, MK Nayak and DS Tomar

abstract
Population dynamics of insect-pests of soybean and there a correlation with abiotic factors were studied at JNKVV, College of Agriculture, Tikamgarh (M.P.).The observations on the incidence of various insect-pests were recorded from germination to harvesting of the crop at weekly intervals. The peak activity of semilooper (5 larvae/mrl) and tobacco caterpillar (1.33 larvae/mrl) were observed in 37^th and 38^th SMW respectively. Whereas the highest population of jassid (3.17 jassid/ 3 leaves /plant) was recorded during 36^th SMW and there was two peaks in whitefly population first was 33^rd SMW (9.17 per 3 leaves /plant) and second peak was 37^th SMW (14.33 per 3 leaves/plant). However the maximum infestation due to stem fly was observed 18.45% tunnel of the stem in 35^th SMW, while the maximum infestation of plant due to girdle beetle was observed 4.33 girdle plant /mrl during 39^th SMW. Based on observations and correlation study of insect incidence with weather parameters, it was found that population of semilooper and tobacco caterpillar larva were significant and positive correlated with maximum temperature and evaporation (r = 0.31, 0.35, 0.55 and 0.61 respectively) and negatively correlated with evening humidity (r =.-0.18 and -0.43 respectively). Whereas the population of whitefly and jassid were significant positive correlated with maximum temperature and evaporation (r = 0.36, 0.24, 0.41 and 0.48 respectively) and negatively correlated with evening relative humidity. However stem fly population was significantly positive correlated with maximum temperature and evaporation (r =0.86 and 0.64 respectively) and negatively correlated with rainfall (r =-0.44). The girdle beetle population was also significantly positive correlated with maximum temperature and evaporation (r = 0.89 and 0.71 respectively) and negatively correlated with relative humidity and rainfall (r = -0.60, -0.89 and -0.44 respectively). From the study it may be concluded that there were two peaks in whitefly population (33^rd & 37^th SMW) and one peak of jassid, semiloope and tobacco caterpillar were recorded at 36^th, 37^th and 38^th SMW respectively. However the maximum infestation of stem fly and girdle beetle were observed during 35^th and 39^th SMW respectively. It was also concluded that all the insects exhibited significant positive correlation with maximum temperature and evaporation while the stem fly and the girdle beetle showed significant negative correlation with minimum temperature, relative humidity and rainfall respectively.