The Effect of Shade Trees in the Coffee Ecosystem to the Population and Diurnal Activity of Insect Pollinators

Abstract

Insect pollinators is one of the important factors in the cross-pollination of coffee flowers, which affects the coffee fruit set. However, there is still a limited understanding of how shade trees in the coffee ecosystem affect insect pollinators. The purpose of this study was to obtain information on the effect of climate variations at different shading levels in the coffee ecosystem to the population and diurnal activity of insect pollinators. The shade levels are categorized in three ways, namely high shade, low shade, and open shade. The observation was conducted at the time when the flower blooms with sample units a flower in two coffee branches. Insect pollinators that show feeding behavior in coffee flowers were recorded in the morning, while the diurnal activity of each species pollinator was observed in the morning, midday, and afternoon. The study showed five species of insects belonging to three families and two orders, Hymenoptera and Lepidoptera that showed feeding behavior on coffee flowers. Apis cerana and Apis mellifera were the dominant pollinators of coffee flowers. The difference in shade levels did not affect pollinator species to visit coffee flowers, but their population tends to decrease in the open shade, except Apis cerana. The peak of diurnal activity of insect pollinator recorded in the morning decreased at midday and showed an increase slightly in the afternoon until the end of the diurnal activity. An increase of temperature may significantly decrease the number of pollinators that visit coffee flowers, while humidity and light intensity showed no significant effect.