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Subject: Entomology × Author: Dalal, Pradeep Kumar × Start date: 2010 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Determination of pollen trapping frequency, pollen collection and hoarding behaviour in Apis mellifera L. colonies
    (CCSHAU, Hisar, 2019-09) Dalal, Pradeep Kumar; Yadav, Sunita
    With a view to explore the potential of pollen load trapping as subsidiary occupation among Indian beekeepers, the present investigations were carried out in 3 seasons (mustard bloom at Hisar and Kaul; multi-floral season at Kaul) during 2016-17 and 2017-18 to determine the optimum pollen trapping frequency that allow economically viable pollen collection as well as sufficient honey production and colony development. Fifteen colonies each of high (12-frame) and medium strength (8-frame) were put to five pollen trapping frequencies viz. daily, alternate days, 3 days, weekly and without trapping (control). The floral biology of dominant flowering crop under different seasons revealed that each flower of mustard, Brassica campestris and Egyptian clover, Trifolium alexandrium offered floral resources to A. mellifera bees for a period of 3 and 3.9 days, respectively. Mean pollen collection from high and medium strength colonies was 14.9 and 8.1 g/colony/day, translating to 1.98 and 1.09 kg/colony, respectively in mustard season. Pollen collection increased with increasing order of trapping frequencies. Pollen collection from high strength colonies from mustard was more in daily pollen trapping (25.3 g/colony/day) followed by alternate (18.4 g), 3 days (17.1) and weekly trapped colonies (14.0 g/colony/day). Similar trend was noticed for medium strength colonies on mustard bloom and multi-floral season, indicating direct relationship of pollen trapping with pollen load collection. Botanical diversity of pollen loads was estimated by employing 3 methods viz. visual, segregation on colour basis and haemocytometer method. Melissopalynological analysis identified 11 pollen types, yellow coloured B. campestris pollen being major source both at Hisar and Kaul comprising >50% of total pollen loads. During multi-floral season (Mar-Apr), white coloured pollen loads from weed, Ageratum conyzoides were in majority during initial phase and T. alexandrium in final phase. Crude protein and calorific value of B. campestris was 24.3% and 367.1 Kcal/100 g while values for A. conyzoides and T. alexandrium were 16.0 and 23.8% and 422.6 and 418.9 Kcal/100 g, respectively. Impact of different pollen trapping frequencies was studied on colony traits viz. honey, nectar, and pollen store, brood area, drone numbers, etc. During mustard bloom, in daily trapping the honey area depleted in high strength colonies (-5.0%) while in medium strength grew by 43.0%. Alternate trapping of high strength and 3 days trapping of medium strength colonies allowed honey area to expand by 95.3 and 73.1%, respectively over season. During multi-floral season, honey area dipped uniformly irrespective of trapping frequencies. Brood development suffered as a result of daily pollen trapping during mustard bloom as high and medium strength expanded by -2.9 and 11.0%. Under alternate trapping of high and 3 days trapping medium strength colony the brood area grew by 22.5 and 49.6%, respectively. During multi-floral season, shortage of good quality major floral source, led to reduction in total brood area across all trapping frequencies. Daily trapping of high strength colonies led to depletion of pollen store area (-24.7%) in colonies which triggered them to additionally recruit maximum proportion of foragers (29.0%) for pollen collection from existing foraging force, impacting other colony functions. Similarly medium strength daily trapped colony recruited additional pollen foraging force of 25.6%. Experimental colonies were also categorized based on pollen hoarding behavior and their sensitivity to hygiene. A total of 14 colonies possessed high pollen hoarding behaviour out of 90 colonies tested during all the season. Moderately sensitive (MS) trait alongside high pollen hoarding character was found in only one of the total lot of colonies. Overall analysis including economics suggested alternate trapping of high strength colonies as more remunerative in comparison to other trapping frequencies with adequate pollen yield, optimum colony growth and honey production with additional economic returns of Rs 264.9 per colony. Among medium strength colonies, 3 days pollen trapping was relatively better with net income of Rs 4.9 as per colony in addition to prolific honey production and brood development.