Investigation on seasonal population fluctuations of jujube lace bug (Monosteira alticarinata) and identification of its natural enemies in Birjand region

The jujube lace bug, Monosteira alticarinata Ghauri is one of the important pests of jujube in South Khorasan province which gained great economic importance in recent years. To study the seasonal population fluctuations of M. alticarinata and its natural enemies, sampling was done weekly from the start to the end of the cropping season during 2020-2021. Jujube leaf was selected as sampling unit. Ten jujube trees were selected, at each sampling time200 leaves (20 leaves from each tree) were collected from different geographical directions and the number of different biological stages of the jujube lace bug as well as its natural enemies were counted using a stereomicroscope. The Pearson correlation coefficient was used to determine the relationship between lace bug density and temperature and relative humidity as variables. The highest population density of egg, nymph, and adult lace bug stages were 394.3±69.09, 114.4±20.5, and 42.4±6.92 on August 15th, September 5th, and August 1st, respectively in 2020 and 434.9±75.31, 126±20.43, and 40±11.50 on August 9th, August 30th, and September 20th, respectively in 2021. In both years, a positive and significant correlation was observed between jujube lace bug total population density (r2020= 0.603, P2020=0.0001 and r2021= 0.475, P2021=0.08) with temperature, however the correlation was negative and non-significant for relative humidity (r2020=-0.265, P2020=0.175 and r2021= -0.349, P2021=0.059). In total, seven ladybird species, one lacewing species, and one parasitic mite species were collected and identified as natural enemies of the jujube lace bug in Birjand. The results of present study can be used in the integrated management of the jujube lace bug.