Madras Agric. J., 105 (7-9): 286-290, September 2018 *Corresponding author’s email: meghavijayanp@gmail.com Efect of Season and Timings on the Foraging Behaviour of Stingless Bee, Tetragonula iridipennis Smith (Hymenoptera: Apidae) Megha Vijayan*, P. A. Saravanan and M.R. Srinivasan Department of Agricultural Entomology Tamil Nadu Agricultural University, Coimbatore - 641 003 Stingless bees are the smallest eusocial bees and crucial pollinators of tropical and subtropical ecosystems. The aim of this study is to analyse the foraging pattern and variability in resource intake of Tetragonula iridipennis Smith among diferent times and months. Foraging pattern of a T. iridipennis colony for pollen, nectar and resin reward collection was recorded from December 2017 to March 2018. The observations revealed that there is a diference in foraging activity within same day during diferent time interval as well as between months. Both pollen and nectar foraging activity was least during early morning (7.00 am to 9.00 am) hours whereas, resin foragers started their foraging activity as early as 7.00 am to 8.00 am. The pollen foraging activity attained peak from 8.00 am to 12.00 pm, resin foraging activity attained peak from 8.00 am to 11.00 but nectar foraging was observed more in noon and evening hours (12.00 pm to 5.00 pm). Foraging for all types of rewards (pollen, nectar and resin) was observed more during the month of March followed by February. Key words: Tetragonula iridipennis, Foraging, Pollen, Nectar, Resin Stingless bees are the smallest of the honey producing bees, commonly distributed in tropical and subtropical countries of the world. There are more than 500 species of stingless bees described all over the world (Michener, 2013). Large proportion of tropical plant species, summing up to one fifth of the local angiosperm flora requires the service of stingless bee pollination (Wilms et al., 1996; Corlett, 2004). The most common stingless bee species of South India is Tetragonula iridipennis Smith (Michner, 1974). The major resources collected by stingless bees are pollen, resin and nectar. Pollen serves as a source of proteins and vitamins whereas nectar act as a source of carbohydrates for the bee’s survival and colony development (Michener, 2007). Stingless bees are also known to collect resin and mud for building nest components and for defence purpose (Roubik, 2006; Leonhardt and Blüthgen 2009; Wallace and Lee, 2010). Brujin and Sommeijer (1997) observed colony foraging in four species of stingless bees viz., Melipona fasciata, M. beecheii, M. favosa and Tetragonisca angustata and found that the foraging pattern of Melipona species was diferent than that of T. angustula. Devanesan et al., (2002) observed foraging activity of T. iridipennis at Kerala, and reported the peak foraging activity at the month of July and least foraging activity during December and January. Danareddi (2007) reported foraging behaviour of T. iridipennis at diferent seasons and also the high activity of outgoing bees in October and November and pollen foraging in the month of February. Most of these studies were related to pollen and nectar foraging and very few studies were done to analyse all the resources i.e. pollen, nectar and resin collected by stingless bees. So the aim of this study is to analyse resource intake and foraging activity of T. iridipennis by recording the number of pollen, nectar and resin foragers and to understand the variability within resources collected during diferent month and time of same day. This information will help the farmers and beekeepers for better utilisation of resources for stingless bees and thus to manage meliponiculture as well as for aided bee pollination. Material and Methods The present study was conducted at Apiary unit, Tamil Nadu Agricultural University, Coimbatore (11°N, 77°E) with an elevation of 409 meters above sea level. A strong colony of T. iridipennis maintained Apiary unit was used for observing the foraging activity. The colony reared in wooden box was connected with a transparent plastic tube at the entrance for recording the observations.The movements of foragers in and out of colony were recorded by direct visual observation at weekly interval for a period of ten minutes per hour from 7.00 am to 6.00 pm in a day during December 2017 to March 2018. The foraging activity was recorded by following the methods of Singh and Khan (2015). The number of foragers leaving their hives with waste materials (cleaner bees) and without waste materials (foragers), the number of foragers returning to their hives with resin load and pollen load was recorded. The pollen basket in metathorasic leg could be filled with pollen in case