Study of population relationship and the effect of several acaricides on the Tetranychus urticae Koch and the predatory mite of Neoseiulus californicus (McGregor) in greenhouse roses

The family Tetranychidae includes the most important species of greenhouse pest mites, among which the two-spotted spider mite is the most important greenhouse pest. In this study, under stable conditions, the relationship between the population of the predatory mite Neoseiulus californicus (McGregor) and the biological stages of the two-spotted spider mite was investigated and a multiple linear regression model was fitted for these variables. It was found that the predator mite prefers the larval stage of the two-spotted spider mite with the highest beta coefficient (Beta= 0.795) over its other biological stages. The efficacy of four acaricides including Polaris® (chlorfenapyr SC 24%), Speed® (chlorfenapyr SC 24%), Flormite® (bifenazate SC 24%) and Dayabon3® (castor oil SL 10%) against this pest and its predator mite was based on a randomized complete block design. The results of the analysis of variance of mortality of egg, larvae, nymph and adult stages of this pest and its predatory mite with treatments on days 3, 7 and 14 after spraying showed that bifenazate 0.5 ml/l, castor oil 8 ml/l and chlorfenapyr (Polaris®) 0.5 ml/l were the highest percentage of mortality in all biological stages at different time intervals, respectively. According to the IOBC classification, the least dangerous compound for the predator mite was castor oil and bifenazate, and the most dangerous compound were both trade name of chlorfenapyr.