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Individual study: Substantial increase in numbers of introduced red mason bees Osmia rufa provided with reed stem nest boxes on farmland near Poznan, Wielkopolskie, Poland

Published source details

Wojtowski F., Wilkaniec Z. & Szymas B. (1995) Increasing the total number of Osmia rufa (L.) (Megachilidae) in selected biotopes by controlled introduction method. Pages 177 in: J. Banaszak (ed.) Changes in the fauna of wild bees in Europe. Pedagogical University,


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Provide nest boxes for bees (solitary bees or bumblebees) Farmland Conservation

A replicated six-year trial at two experimental farms near Poznan, western Poland (Wójtowski et al. 1995) demonstrated that the red mason bee Osmia rufa readily nests in bundles of reed Phragmites australis stems 7-8 mm in diameter. Bundles of reed stems in roofed containers were set out in March from 1989 to 2004. In winter each year, occupied reed stems were collected and kept in refrigerators over winter. The following spring, overwintered reed stems were placed out in incubators along with new nest boxes. In the first year (1989), 1,750 red mason bee cocoons were introduced with the nest boxes at each site. The behaviour of emerging bees was observed. At one site the total number of emerging red mason bees increased from 1,453 in 1989 to 108,973 in 1994 (a 75-fold increase). At the other site the number of emerging red mason bees increased from 1,519 in 1989 to 13,413 in 1992, after which the population was resettled for other experiments.

 

Provide artificial nest sites for solitary bees Bee Conservation

A six-year trial at two experimental farms near Poznan, western Poland demonstrated that the red mason bee Osmia rufa readily nests in bundles of reed stems 7-8 mm in diameter (Wojtowski et al. 1995).

Rear and manage populations of solitary bees Bee Conservation

In a trial at two experimental farms near Poznan, western Poland from 1989 to 1994, the numbers of red mason bees Osmia rufa nesting in bundles of reed stem increased substantially year on year. Each winter, occupied reed stems were collected and healthy bee cocoons (not parasitized) were transferred to refrigerators and kept at 4°C over winter. These were placed out in incubators along with new nest boxes the following spring. At one site, the number of emerging bees increased from an originally introduced 1,453 bees in 1989 to 108,973 in 1994 (a 75-fold increase; Wójtowski et al. 1995). The number of emerging females each year was between 1.3 and 5.7 times the number of females the previous year. Based on these numbers, the density of red mason bees on the farm was estimated to have increased from 1 bee/ha to 1,353 female bees/ha or more over the six years. Bee numbers nesting at the second site followed a similar trajectory, but the experiment was ended after three years.