Seasonal fluctuations in incidence of ber fruitfly Carpomyia vesuviana Costa (Diptera: Tephritidae) under agro-climatic conditions of Hisar
Lakra, R.K.; Zile Singh
Haryana Agricultural University Journal of Research 15(1): 42-50
Field observations in Hisar, Haryana, India, in 1979-81 on the seasonal incidence of Carpomyia vesuviana, an important pest of jujube (Ziziphus spp.), are described. Activity of different stages of the tephritid continued at temperatures of -1.7-46.7 degrees C and relative humidities of 5-100%. Extremes of meteorological conditions had a greater effect on adult activity than on larval activity. An increase in the daily maximum temperature to >40 degrees C, together with a low relative humidity (20-30%) was unfavourable for pest development. A drop in temperature to <5 degrees C prolonged the duration of the immature stages. Intermittent light rainfall of 20-40 mm/week during July-August enhanced adult activity, while moderate to heavy rainfall of 50-120 mm/week curtailed adult activity. Mean weekly minimum and maximum temperature ranges of 10-25 and 25-40 degrees C, respectively, and morning and evening relative humidities of 25-90% were ideal for pest activity. Larval incidence in fruits reached a peak in August-September on Z. nummularia and in July, January and April on Z. mauritiana; peak incidence on the 2 species reached 76.8 and 47.4%, respectively. Parasites of the fly were present only in small numbers.