Conservation Evidence strives to be as useful to conservationists as possible. Please take our survey to help the team improve our resource.

Providing evidence to improve practice

Individual study: Providing wooden nest blocks enhances numbers of megachilid bees Osmia spp. in lowbush blueberry Vaccinium angustifolium fields in Washington County, Maine, USA

Published source details

Stubbs C.S., Drummond F.A. & Allard S.L. (1997) Bee conservation and increasing Osmia spp. in Maine lowbush blueberry fields. Northeastern Naturalist, 4, 133-144


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

Provide artificial nest sites for solitary bees Bee Conservation

In a replicated trial in Washington County, Maine, USA, Stubbs et al. (1997) added 50 drilled wooden nest boxes to each of three blueberry fields Vaccinium angustifolium over three years. The nest boxes each had 14 holes and were attached to trees along the field edge, at a height of 1.4 m, with 22-33 m between each box. In the first year, 30 nest boxes were occupied by bees of the genus Osmia, with 120 nests made. The number of nests increased the following year in all three fields. Between 3 and 11.5% of nesting holes were occupied at all three sites, each year.

Provide artificial nest sites for solitary bees Bee Conservation

In a small replicated trial in Washington County, Maine, USA, Stubbs et al. (1997) added 50 drilled wooden nest boxes to three experimental blueberry fields Vaccinium angustifolium over three years from 1993 to 1995. The percentage of holes occupied rose from around 3% in the first year to over 7% in the third year in two fields, but did not rise substantially in the third field, remaining between 5 and 7%. Numbers of bees of the genus Osmia foraging on blueberry flowers in the experimental fields and in three control fields without nest boxes were monitored, using quadrat counts and sweep net sampling. In the first year, estimated numbers of Osmia ranged from 0 to 879 bees/ha in both control and experimental fields. In the third year, control fields had between 0 and 440 bees/ha, while experimental fields with nest boxes had from 219 to 1328 bees/ha. The numbers of foraging bees had increased in two of the three fields with nest boxes.