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A b s t r a c t The effects of pollen protein content on the colony development of Bombus terrestris were investigated by feeding queens and queenright colonies with four different pollen diets. We used three kinds of commercially available pure pollen (Cistus spp. 11.9%, Papaver somniferum 21.4%, and Sinapis arvensis 21.8% crude protein). We also used a mixture which was made up of equal weights of these pure pollens (18.4 % crude protein). All queens and colonies were fed with sugar syrup and pollen diets ad libitum (28 ± 1 o C, 65 ± 5% RH). Until there were 50 workers reached, colonies fed with the Cistus pollen diet (167.4 ± 28.9 g) consumed signifi cantly more pollen than colonies fed with the Papaver pollen diet (140.7 ± 15.7 g), the mixed pollen diet (136.2 ± 20.1 g) or colonies fed with the Sinapis pollen diet (132.4 ± 22.6 g). The date when there were 50 workers reached was approximately one week later in the colonies fed with the Cistus, and colonies fed with the Papaver diet than in the colonies fed with the Sinapis diet, and for colonies fed with the mixed pollen diets. Considering 8 tested criteria, the best performances were observed using the Sinapis, and using the mixed pollen diets. The lowest performances were observed using the Cistus pollen diet. Results showed that pollen sources play an important role in commercial bumblebee rearing. Results also showed that the polyfl oral pollen diets are more suitable for mass rearing of bumblebees than the unifl oral pollen diets.

Life-cycle and foraging patterns of native Bombus terrestris populations were investigated at two sites in the Mediterranean region of Turkey, Phassalis (0 -100 m above sea level [a.s.l.]) and Termessos (500 -700 m a.s.l.). Bumble-bee activity was recorded during standard bee walks from November 2003 until the end of October 2004, each site being visited three times every month during the one-year period. The yearly dynamics of flight, the flowering plant species visited, and the visitation frequencies of these plants were recorded during every bee walk at both sites. There were considerable differences between the two populations with regard to the dates when the queens emerged from diapause (the emerging season), the timing of the appearance of sexuals (young queens and males), and the total number of plant species visited. Bombus terrestris queens emerged from diapause in November-December at the Phassalis site (coastal area) and in February-March at the Termessos site. The queens aestivated at the Phassalis site, whereas they hibernated at the Termessos site. Only one generation per year was produced at each site. The duration of the queens diapause lasted 5 -8 months and length of the life cycle 190 -215 days. Native B. terrestris populations were noted to forage on 47 flowering plant species from 20 families (10 at the Phassalis site and 40 at the Termessos site) during the study period. Two of the plant species (Arbutus unedo L. and Vitex agnus-castus L.) have long flowering periods and play a crucial role in the life cycle of native B. terrestris populations. The emergence of queens at the aestivation site was synchronized with the flowering of Arbutus unedo L., while the emergence of sexuals coincided with the flowering of Vitex agnus-castus L. at both sites.

The effects of different stimulation methods on colony development of Bombus terrestris queens were examined to increase rearing efficiency and reduce production costs. A total of 350 hibernated queens obtained from a commercial company were used. Each queen was placed separately in the starting box and four starting methods were tested: only the queen (q), one queen stimulated with one B. terrestris worker (qtw), one honeybee worker (qhw), and one B. terrestris pupa (qtp). There were significant differences among the treatments in terms of egg laying, colony production and saleable production ratio, the colony initiation time, the time of the emergence of the first worker, the number of egg cells in the first brood. Starting methods had no significant effect on the other colony characteristics. The highest egg laying ratio, colony production ratio and saleable colony production ratio were found in the qtw group (82.8, 53.3, 39.0%) followed by qtp (72.8, 42.8, 28.5%), qhw (57.1, 28.6, 16.2%) and q (35.7, 17.1, 14.3%) groups, respectively. The queens with qtw treatment developed more egg cells (4.39Ϯ0.21) in the first brood and started egg laying (11.75Ϯ0.83 days) earlier than in the other treatments. The results showed that adding a B. terrestris worker is the best starting method for the mass rearing of B. terrestris. Qtp treatment was found to be the second most successful starting method.

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