Diversity and Foraging Behavior of Insect Visitors on Pollination of Agarwood (Aquilaria crassna Pierre ex Lec.) flowers at Khao Yai National Park

Abstract

Flower visitors were collected from natural forest in Khao Yai National Park using air-flight Malaise traps, hand nets and by observation of foraging behavior. The data was collected during the Aquilaria crassna Pierre ex Lec. flowering season in March, April and May of 2006 and 2007. In total, 86 species from 4 orders and 34 families were found, of which, 46 species from the order Lepidoptera were the most common on flowers, followed by Hymenoptera, Diptera and Coleoptera with 25, 8 and 7 species, respectively. The highest frequencies of individual visitors on the flowers occurred during 20:00-22:00 and 10:00-12:00. In contrast, the lowest activity on the flowers was during 04:00-06 :00. Regarding foraging behavior, moths spent the longest time on the flowers (25.36±1.78 (n=46) s /flower), while wild bees spent the shortest time (8.66±0.76 (n=27) s/flower). The results indicated that the nocturnal group (first pollination) and the diurnal group (second pollination) are the two major insect groups playing an important role in the pollination of agarwood .

Keywords: diversity, insect visitors, Aquilaria crassna, insect foraging behavior