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  • Author: Aleksandra Łangowska x
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Bożena Szymaś, Aleksandra Łangowska and Magdalena Kazimierczak-Baryczko

Histological structure of the Midgut of honey bees (Apis Mellifera L.) Fed Pollen Substitutes Fortified with Probiotics

The aim of this investigations was to assess morphological changes in the midgut epithelium of bees nourished with pollen substitute or pollen substitute enriched with a probiotic preparation. One-day old worker bees were kept in cages placed in a temperature controlled environment. During the two-week feeding period workers were fed beebread (control), pure pollen substitute or pollen substitute fortified with three different doses of probiotic preparations: Biogen or Trilac (experimental groups). The assessment of histological changes of the bee midgut was carried out in bees feed for 8 and 14 days. Slight changes in the epithelium as well as strong merocrine-type secretion were recorded in bees nourished pollen substitute supplemented with probiotic preparations. Differences were observed, primarily, in quantities of the developed peritrophic membranes. Their quantities were particularly high after 14 days of feeding with the pollen substitute fortified with probiotic preparations. The development of numerous peritrophic membranes could have contributed to better utilization of nutrients contained in feed and better condition of bees.

Open access

Monika Fliszkiewicz, Aleksandra Langowska and Piotr Tryjanowski

Abstract

The red mason bee Osmia bicornis L. (Hymenoptera: Megachilidae) is a solitary gregarious species that is known to be a good pollinator of pear, apple, and several other Rosaceae fruit plants. Mainly females are active in plant pollination, and therefore they are of strong interest to farmers. As natural populations are usually male biased, here we studied the possibility of rearing a female-biased population of Osmia bicornis by examining the effects of sex ratio changes on female survival, insemination rate, and sperm count in the spermatheca. Using bees that had completed their winter diapause and were maintained in flying cages, we created three groups with different male:female sex ratios: 1:1, 1:2, and 1:3. The 1:3 sex-ratio group exhibited the best survival of females, but the lowest spermathecae sperm count. The insemination rate did not differ between groups. Our results indicate that-at least among bees housed in isolator cages for plant breeding- skewing the sex ratio towards more females does not affect bee survival, and efficient insemination can be expected with twice as many females as males.

Open access

Aleksandra Łangowska, Reuven Yosef, Piotr Skórka and Piotr Tryjanowski

Abstract

Bee-eaters (Meropidae) are considered agricultural pests and their presence provokes conflicts with beekeepers and farmers who rely on the pollination services of honey bees. This problem is often deal with through the mass killing of the birds, even though the quantitative evidence on the impact of bee-eaters on honey bee colonies is scarce. The current paper reports the performance of honey bee colonies protected with mist nets from migrating flocks of European bee-eaters Merops apiaster in Israel. In the study the weight gains of bee hives surrounded by mist nets were 6.44 times higher than that of unprotected hives (26.4 kg vs. 4.1 kg). The results confirmed that bee-eaters locally pose a problem to apiaries and potentially to the crops that require pollination. Mist- netting appeared to be an effective mitigation method for alleviating conflicts between beekeepers and bee-eaters. However, the study also showed that bees were able to differentiate between their main predator and other avian species trapped in mist nets and stung only bee-eaters. Moreover, the bees were targeting the most vulnerable body parts of birds which resulted in some bird fatalities. Therefore, due to accidental mortal- ity of birds, mist-netting is recommended only on the migratory routes in cases when bee hives cannot be moved to other areas.