ISHS Acta Horticulturae 437: VII International Symposium on Pollination
BEES VERSUS FLIES ? - REARING METHODS AND EFFECTIVENESS OF POLLINATORS IN CROP GERMPLASM REGENERATION |
| Author: | T. Gladis |
| DOI: | 10.17660/ActaHortic.1997.437.25 |
| Abstract:
Small plant population size of cross-pollinated species is characteristic of accessions maintained in genebanks. Different entomophilous crop species are grown together in isolation sites at the IPK-genebank. These plants flower in different periods and require various pollinator species. Various bee species have been reared: Apis mellifera, Bombus spp., Psithyrus rupestris, Megachile rotundata, Osmia rufa and Anthophora acervorum as well as blow flies, flesh flies and hover flies for crop pollination in isolation cages and glass houses. Osmia rufa is the most effective pollinator, e.g. for cruciferous crops. It is very easy to handle as bee cocoons may be ordered between September and December. The flies were compared as pollinators with partially distinct flower preference. Their broader application for crop pollination and other purposes depends on a rearing technique which is usable throughout the year. This paper presents a simple and hygienic method for keeping large populations of Eristalis tenax (Syrphidae, Eristalinae) in captivity. Some information about its biology and behavior under artificial conditions in comparison with related species is given. Using Red mason bees with this common hover fly species guarantees maximum pollination, best seed set and lowest labor effort. Different pollinator densities have to be recognized, i.e. one tunnel of bee cells for the solitary bee or about 20 hover flies seems to be sufficient to pollinate about 20 m2. Competition between these insect species was low. Discontinuity in the rearing of several species guarantees a sufficient abundance of pollinators, especially from June to August. In this way, damages caused by para- and episites can be minimized. | |
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