PRELIMINARY INVESTIGATION OF OSMIA CORNUTA LATR. (HYMENOPTERA, MEGACHILIDAE) AS A POTENTIAL POLLINATOR FOR BLACKBERRY (RUBUS FRUTICOSUS L.) UNDER CONFINED ENVIRONMENT

The possibility of using the solitary bee Osmia cornuta Latr. as a pollinator of two cultivars (Black Satin and Hull Thornless) of blackberries (Rubus fruticosus L.) under confined environmental conditions was investigated: first, by releasing 300 adults associated with three artificial nests within the tunnel to verify the possibility to multiply them in confined conditions.
Second, by using cages with only Osmia in them. Osmia pollination was compared with honey bee, wind, self and open pollination.
Comparison among treatments was by the number of drupelets and berry weight.

Osmia pollination was different on the two cultivars.
In the Hull Thornless cultivar, Osmia pollinated berries were significantly heavier and had more drupelets than self, wind and open pollinated ones, but were similar to honey bee pollinated berries.
In the Black Satin cultivar, Osmia pollinated berries were statistically different from the open, wind, and self pollinated ones in weight and from self and wind in number of drupelets There were no differences between Osmia and honey bee pollinated berries in this cultivar.

Osmia increased its population two times (588 cocoons) and the sex-ratio (M/F) was 4.5:1. Analysis of the pollen provisions collected from the artificial nests confirmed that the bees visited the blackberry flowers in a confined environment and intensively gathered pollen from them.

VII International Symposium on Pollination

M. Pinzauti, D. Lazzarini, A. Felicioli

https://doi.org/10.17660/ActaHortic.1997.437.40