The mealybug (Planococcus kraunhiae) is one of serious insect pests that cause negative effects on growth, productivity and quality of coffee in Dak Lak. Rain decreases strongly the density of the mealybugs. With rainfall of 88 mm. the mealybug density is reduced from 41,41 - 51.64 percent after one rainy day and 60.75 - 72.31 percent after three rainy days. In the rainy season, this species is more reduced in the bottom - canopy than in top - canopy. The mealybugs prefer dry weather conditions. as a result the density of mealybugs on hill - tops is higher than at hill - bases
on hilltops the density was 42.92 individuals/twig in 2006 and 58.75 individuals/twig in 2008. but at the hill-base there were 14.72 individuals/twig in 2007 and 36.58 individuals/twig in 2008. the study showed that the mealybugs cause more severe damage on coffee during the commercial stage than at the basic construction stage
13.2 individuals/twig versus 0.67 individuals/twig, respectively.