Distribution and control of pink pineapple mealybug and survey of insect pests on pineapple.
Surveys of insect pests on pineapple were carried out from 2010 to 2012 in three major pineapple cultivation areas in Taiwan. The results showed that pink pineapple mealybug [Dysmicoccus brevipes (Cockerell)] occurred more frequently than the other insect species, and three species of insect pests, boisduval scale (Diaspis boisduvalii Signoret), smilax scale [Melanaspis smilacis (Corn-stock)] and Taiwan tussock moth [Porthesia taiwana (Shiraki)] were newly recorded on pineapple in Taiwan. By analyzing the pattern of spatial distribution of pink pineapple mealybug, results showed that it was an aggregative type of insect in the field. Its population mainly concentrated on the basal part of pineapple, and was positively correlated with the soluble solid contents on different parts of fruit. The control efficacy of three chemicals, namely, 50% Fenitrothion EC, 50% Fenthion EC and 40.8% Chlorpyrifos EC, that were recommended for pink pineapple mealybug in the earlier time remained effective in this study. These chemicals effectively controlled the insect on the 21th day after the second application. However, four non-synthetic chemicals adopted in this study, 2% coconut oil, 90% sunflower oil, 60% soybean oil and 99% mineral oil, had no effect on pest control.