Sun, J.H., & Zhang, Y.Z. 2003 Effects of insecticide application on Oracella acuta (Lobdell) (Homoptera: Pseudococcidae) population and its two dominant parasitoids.. Acta Entomologica Sinica 46(4): 466-472.
Notes: The effects of insecticide application on loblolly pine mealybug, O. acuta and its two dominant parasitoids, Allotropa sp. and Zarhopalus debarri, were investigated using yellow sticky traps. The results revealed that the Oracella population responded positively to the intensity of insecticide use, which had adverse effects on its two parasitoids. In fact, the outbreak of the mealybug was largely due to this adverse effect of insecticides on its parasitoids. Orchards with high intensity use of insecticides resulted in higher Oracella population density and vice versa. Comparison of three orchards with three levels of insecticide use further demonstrated the effectiveness of the parasitoids in regulating mealybug populations. Significantly more males of Zarhopalus sp. were caught than females, which indicated a sex preference for yellow in this species. A strong positive correlation exists between Oracella and its parasitoids but this relationship can be disrupted by the heavy use of insecticides.