Understanding the biology and improved management of longtailed mealybug in WA

Abstract

Understanding the biology and improved management of longtailed mealybug in WA

Summary

Longtailed mealybug has become a more important pest in an increasing number of winegrape vineyards in south west Western Australia. This study was concerned with their management and sought to clarify the role of predators and insecticides. This study was not able to quantify the role of naturally occurring or introduced predators. The abundance of naturally occurring predators was usually too low to expect they would reduce pest populations to satisfactory levels. With respect to the role of the introduced predators Cryptolaemus beetles and green lacewing, it was noted that claims as to their effectiveness by vignerons varied from almost no effect to very worthwhile. Detailed monitoring in field trials would be required to clarify their role.

The results of an insecticide screening trial indicated that the abundance of longtailed mealybug could be reduced during the season by pre bud burst sprays of chlorpyrifos and bifenthrin. The growth regulator insecticide buprofezin also reduced pest numbers but at a slower rate. Multiple applications of paraffin oil may be the only way this product may help control mealybug. Carbaryl resulted in short term reduction of mealybug numbers only.

Large plot field studies would help to clarify some of the unknowns regarding the role of predators and impacts of insecticide applications on management and pest status of longtailed mealybug.