Management of Mealybug in Managosteen

Abstract

Series of experimental trials on management trials on management of mealybug in mangosteen were conducted at the Laboratory of Entomology and Zoology Group, Plant Protection Research and Development Office and grower orchards in Chantaburi and Rayong province during October 2003-June 2005. It was found that Pseudococcus cryptus Hempel is the most important mealybug of mangosteen, their outbreak took place on fruit about 2 months after fruit seeting. When rearing on pumpkin fruit at 28-32 C, 60-80% RH, the female pass through 3 nymphal instar, passes through a prepupal and pupal stages in flimsy cocoon before becoming an dult. The adult males are tiny, two-winged while the females are wingless throughout life. On mangosteen, mealybugs feed by sucking plant sap under the sepals and are difficult to control. Studies on the natural enemies of mealybug were conducted in Rayong and Chantaburi by random survey, revealed that green lacewing (Mallada baslis Walker), coccinellid bettel (Nephus ryuguus (H. Ksamiya)) and eulophid parasitoids wee the mos teffective natural enemies in mangosteen orchards, especially the green lacewing ate 6.08-9.16 crawlers per day. In the field, carbosulfan (Posse 20% EC) imidacloprid (Confidor 100 SL 10% SL) dinotefuran (Stargle 10% WP) and carbaryl (Sevin 85% WP) at the rates of 50, 10 ml, and 20, 60 g per 20 litres of water gave a good control for this mealybug. In post harvest, the appropriate measure for controlling mealybugs on mangostten is air pressured spray at 20 psi for 15 seconds per fruit. At 7 days after treated the percentage of efficacy was 98.69-99.10%.