Environmental correlates of the potato tuber moth<i>Phthorimaea operculella</i>(Zeller) (Lepidoptera: Gelechiidae)

Abstract

Abstract Field experiments were conducted to study the relationship of environmental factors for the survival of the potato tuber moth, Phthorimaea operculella (Zeller), in the states of Kamataka (sub‐tropical climate) and Ootacamund Tamil Nadu (temperate) during 1987–1989. The sex pheromone‐baited water trap was designed for mass trapping the adult potato tuber moths. It was found that the peak populations of 545 moths/trap/2 weeks and 410/moths/trap/2 weeks were recorded at Ootacamund (Tamil Nadu) and Chikaballapur (Kamataka) during March and June respectively, which coincided with the planting season in these regions. The peak population was 247 moths/trap/2 weeks during November at APMC market yard, Yeshwanthpur, Bangalore. The moth population had positive correlations with temperature and wind velocity for two locations, viz. Chikaballapur and Ootacamund. The correlation coefficient values were 0.61 and 0.53 for temperature, and 0.65 and 0.66 for wind velocity at Ootacamund and Chikaballapur, respectively. Rainfall had a negative correlation at Ootacamund. A significant correlation was observed with sunshine hours at Ootacamund whereas a negative correlation was observed at Chikaballapur. The population showed significant positive multiple correlation with weather parameters and the values of the multiple correlation coefficient were 0.84 for Chikaballapur and 0.86 for Ootacamund. The coefficient of determination (R2) predicted 70.74% changes in trap catches. Peak population catches were observed between 18.00 and 20.00 and moon‐light was shown to have no effect. Keywords: phenologypotato tuber mothsurvivalvolunteerabiotic factor Notes Present address: Central Potato Research Station, Kufri, Shimla‐171 012, Himachal Pradesh, India.