A study was conducted in Kaski and Lamjung districts of Central Nepal (during 2003/2004 and 2008/ 2009) to find out the plant species visited by the bees and their visiting time and season.
The research questions were: which season is the main flowering season in these hilly regions? Which plants are the most commonly visited by bees? Which seasons are the abundant/dearth seasons for the bees? Can we make a bee calendar based on these studies and recommend some common and important plants for the bee keeping? Field survey was conducted during Sep, Oct & Dec of 2003; Jan, April & May of 2004; June, July, Aug & Nov of 2008 and Feb & March of 2009. Observations were made on the bees’ activities on flowers of different plant species and other relevant informations were collected from the farmers through informal interviews. The plant species visited by the bees and the bee species themselves were collected, preserved and identified. They were categorized as major, medium and minor sources of pollen and/or nectar. The pollen and nectar statuses in different plants were also determined. Data verification was done through published literatures and some melissopalynological studies.
Results/Conclusions
From the field survey, 162 plant species were identified as important bee flora. They were categorized in different groups depending upon their resource potentials. Out of which, 35 species were recognized as the major sources, 39 as medium and 35 as minor for both nectar and pollen. Similarly, 49 species were identified as major nectar sources, 53 medium and 45 minor; 51 species as major pollen sources, 54 medium and 49 minor. Plants like Zea mays , Eclipta prostrata, Ageratum conyzoides, and Alnus nepalensis were visited by bee mainly for pollen, whereas Mentha spicata and Bombax sp. were visited for nectar only. Months from February to April and August to October were found as the honey flow seasons. Brassica, Citrus, Pyrus, Berberis, Rubus, Callistemon, Bombax and Artemisia are some of the important plants which bloom during this season. Winter season (mid Nov to Jan) and rainy season (June and July) were identified as the dearth periods for bees. Some of the plants that bloom during winter are Pisum, Ipomoea and Eupatorium. Similarly, Lagerstroemia, Impatiens, Sesamum, Zea and many cucurbits bloomed during rainy season. Based on available flora, food sources and flowering duration, a bee floral calendar was also developed.
