Flower and fruit development and flower-visiting insects of gmelina (Gmelina arborea roxb.)

Abstract

The purpose of the research was to identify flower development and fruit formation as well as identification of flower-visiting insects as potential pollinators. Observations carried out in three sample trees, and five flowering branches at each sample tree were marked. We also carried out the identification of flower-visiting insects, foraging behavior, visiting rate, number of visiting insects, and time of flower visit. The results showed that in one year, 2-3 reproductive cycles might occur, which one cycle lasted about 1-2 months. In a panicle of flowers, flower buds, flower bursts and fruitlets are found simultaneously. The panicle has 5-34 flower buds. The development of buds to panicle formation takes 5-7 days, while the time required for flower and fruit development from generative buds up to yellow fruit was in a range between 38 to 67 days or 1 to 2 months. The total reproductive success of sample trees was varying from 12% to 17%. The most dominant flowers-visiting insects and alleged as pollinators of G. arborea is a carpenter bee (Xylocopa latipes) that actively visiting flowers at 8:00 until 11:00 am. Insect visited about 5 to 20 flower panicles with an average of 11 flower panicles per minute.