HOARDING BEHAVIOR AND LIFE-SPAN OF WORKERS OF APIS-MELLIFERA AND APIS-CERANA

Wooden cages (10 x 8 x 8 cm), each containing 50 cm2 of empty comb and 50 newly emerged workers of either Apis mellifera or A. cerana, and e quipped with feeders supplying 50% sugar syrup and water, were kept in an incubator at either 15-degrees-C, 20-degrees-C, 27-degrees-C or 35 -degrees-C (n = 6 cages/treatment). Hoarding, the amount of syrup cons umed plus syrup stored, was measured by weighing the syrup feeders eve ry 24 h and was expressed as a 6-day average for days 1-6, 7-12, 13-18 , 19-24 and 25-30 of the experiment. Dead bees were counted and remove d from the cages. Hoarding was maximal between days 7 and 12, e.g. at 27-degrees-C it was 80.68 +/- 1.55 mg/bee/day for A. mellifera and 60. 80 +/- 1.29 mg/bee/day for A. cerana. Hoarding decreased steadily afte r this, reaching 49.98 +/- 0.87 and 41.08 +/- 0.83 mg/bee/day for A. m ellifera and A. cerana, respectively, after 25-30 days (at 27-degrees- C). A. mellifera bees hoarded significantly more syrup (P < 0.01) than A. cerana, probably because of their larger size. Hoarding was maxima l at 35-degrees-C for both species; between days 7 and 12 it was 131.9 4 +/- 1.98 mg/bee/day for A. mellifera and 106.57 +/- 3.24 mg/bee/day for A. cerana. In both species, lifespan was highest (A. mellifera, 28 .45 +/- 0.74 days; A. cerana, 28.57 +/- 2.17 days) at 35-degrees-C.