Lasioglossum (Evylaeus) apristum was studied at 2 localities in Japan. By rearing bees in a greenhouse in Matsue (lat. 35°29¢, alt. 170 m), south-western Japan, it was revealed that the bees had an eusocial life cycle with 2 distinctly discrete brood rearing periods, i.e., a solitary phase in spring and an eusocial phase in summer. The life cycle and sociality were of the same pattern as those at Mt. Daisen (lat. 35°22¢, alt. 800-1000 m), 50 km from Matsue, where females reared in the greenhouse were collected. On the other hand, in Sapporo (lat. 43°03¢, alt. 20 m), northern Japan, the solitary life cycle was suggested by a phenological survey. The effective accumulative temperature was compared for each locality, as an index of local thermal condition. The accumulative value at Mt. Daisen and Sapporo did not differ. The fact suggests that short flying season at high latitudes, such as in Sapporo does not induce the solitary life cycle in L. apristum. Approximately 39% of workers in the eusocial colonies at Matsue had well-developed ovaries, suggesting that they were possible egg-layers. No clear proof of the allocation of foraging in relation to the size and age of workers was obtained. Uninseminated, small, worker-sized females were also produced, together with new queens at autumn at Mt. Daisen. Hibernation by these uninseminated females was suggested. The size-linked color patterns of the metasoma were recognized among the pre-hibernating females at both localities.

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BackgroundCentral Asia is one of the important centers of bee diversity in the Palearctic Region. However, there is insufficient information for many taxa in the central Asian bee fauna. The Kyushu and Shimane Universities (Japan) Expeditions to Kazakhstan, Kyrgyzstan, Uzbekistan, and Xinjiang Uyghur of China were conducted in the years 2000 to 2004 and 2012 to 2014.New informationEighty-eight species of the bee family Halictidae Thomson, 1869 are enumerated including new localities in central Asia. Halictus tibialis Walker, 1871, H. persephone Ebmer, 1976, Lasioglossum denislucum (Strand, 1909), L. griseolum (Morawitz, 1872), L. melanopus (Dalla Torre, 1896), L. nitidiusculum (Kirby, 1802), L. sexnotatulum (Nylander, 1852), L. subequestre (Blüthgen, 1931), L. sublaterale (Blüthgen, 1931), and L. zonulum (Smith, 1848) are recorded from central Asia for the first time. Thirty-two species are newly recorded from Kazakhstan, 19 spp. from Kyrgyzstan, 2 spp. from Uzbekistan, and 11 spp. from Xinjiang Uyghur of China. The genus Lasioglossum dominated the number of species and individuals in the collection. The halictid fauna mostly composed of western to central Asian elements in our surveyed area.

To evaluate the pollination efficiency of a stingless bee, Melipona quadrifasciata, individuals originating from tropical and subtropical regions of South America were examined on tomatoes (cv. Momotaro 8) cultivated in a greenhouse in summer and autumn. We compared differences in the rates of foraged flowers, pollen weights foraged from anthers, rates of fruit set of tomatoes, seed number of tomato fruits and yields of tomato fruit weight between M. quadrifasciata and the bumblebee, Bombus terrestris. When the amount of tomato pollen was sufficient, there were no differences in pollination efficiency between the stingless bee and the bumblebee; however, the rates of foraged flowers, the rate of fruit set and the yields were significantly reduced in the stingless bee compared with the bumblebee when fertile tomato pollen decreased markedly during the hottest period of the summer. During this period, the rate of flowers foraged by bumblebees did not decrease, but the rates of fruit set, the seed number and the yields of tomato fruits decreased significantly in comparison with the other periods. It is known that tomato pollen production is inhibited at high temperatures; thus, we consider that the high temperatures in the greenhouse (average daily temperature higher than 28°C) caused the extreme decrease in pollen production. These results indicate that M. quadrifasciata can be used as a suitable pollinator of tomatoes if sufficient amounts of fertile pollen are provided.

Pollination efficiency of hairy footed flower bee Anthophora plumipes for greenhouse strawberry was evaluated in a small greenhouse located in Shimane University, Matsue, Japan (lat. 35˚29', long. 133˚27' and elevation 170 m). Twenty five female and six male bees were released in a greenhouse on April 15, 2014. Red clay soil blocks were provided as the nesting materials. Two hundred and fifty pots of strawberry (Fragaria annanasa) were allocated for the following three treatments: 1) no supplementary pollination (control), 2) hand pollination, and 3) bee pollination. Both male and female bees effectively foraged flowers throughout the day. Rate of fertilized seed by the bee pollination was significantly greater than no supplementary pollination (control) and similar to that in the hand pollinated flowers. Quality of the fruits (evaluated based on the shape and deformity) was also improved by the bee pollination. A. plumipes effectively pollinated strawberry flowers in the greenhouse and could be developed as an alternative pollinator for this crop.