author(s)
N Chaudhuri, D Banerjee, A Ghosh and SK Senapati

abstract
The present study was aimed to identify the prediction model on population buildup of major insect-pest of safflower, the safflower aphid, Dactynotus carthemi HRL for timely intervention for its management. The study was carried out in the Instructional farm of Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal, India during December, 2013 to May, 2014. The result showed that the abiotic factors altogether contributed 95.7% variation in aphid infestation. The maximum temperature had 69% contribution in the population buildup. Temperature regime between 16-20 °C minimum temperature to 31-36 °C maximum temperature was found most important for population buildup of safflower aphid. Prajneshu growth model (IASRI model) was found to be most suitable non-linear growth model for prediction of the pest population build up. The pest population starts increasing on and from 13th standard week. The optimum time to take control measure was in the 15th standard week as a prophylactic measure to check the peak pest population, which was attained at the 16th week (103.26/5cm) and maintained at higher level till 17th week as evidenced from pattern of population growth. So, the Prajneshu growth model can be explored for predicting the population buildup of the pest as well as exact time for intervention through insecticidal application to avoid the crop loss.