Les sources de pollen et de nectar dans la région de Rimouski, Québec, CanadaJ. Parenta, M.J. Feller-Demalsyb and P.J.H. Richarda
a Université de Montréal, département de géographie, laboratoire de paléobiogéographie et de palynologie, CP 6128 Succ A, Montréal Que, Canada, H3C 3J7
b Université du Québec à Rimouski, département de biologie et des sciences de la santé, 300, allée des Ursulines, Rimouski, Que, Canada, G5L 3A1
Abstract - Pollen and nectar sources near Rimouski, Quebec, Canada
In 1980, the study of pollen yields and honeys from the same hive was conducted near Rimouski, in the Lower Saint-Laurence River region (fig 1). Pollen yields were collected daily using a trap placed on a new colony. Half of the yields were examined through sorting of pellets (Louveaux, 1958a). Honey samples, covering one week each, were extracted at the end of the season using photographic comparison of honeycombs. Standard meteorological data were recorded daily, and weekly surveys of flowering plants were performed within a 1.5 km radius around the apiary (fig 1). A total of 1 226 g of fresh pollen were extracted from the trap during a 3.5 mth period (table I). Considering the trap efficiency, around 12.5 kg of fresh pollen were collected by the bees for a mean of 3.6 kg/mo. This result is remarkable, considering the restraints imposed on the colony and the bad weather conditions of 1980. On 60 taxa identified in the pellets (fig 2), only 16 displayed individual values greater than 1% of the total pollen crop (table II). The main pollen sources (> 10%) were : Trifolium hybridum / T repens, Cornus stolonifera, and Salix spp. Mixed pollen pellets were recorded in 65% of pollen yields but they represent only 0.4% of the total yield. Thirty-six (36) taxa were identified in mixed pellets (table III). Pollen analysis of 13 successive honeys and 3 annual ones from the same apiary showed the presence of 42 taxa (fig 3). Other information about these honeys is given in table IV. Most of the honeys are poor in pollen grains. Honeys from the beginning of the season are mixed floral; they are replaced by Rubus idaeus monofloral honeys and then by mixed honeys preceding monofloral honeys of Trifolium hybridum / T repens. The last successive honey presents a double dominance with Medicago sativa. Rubus and Trifolium association is also found in the 3 annual honeys. Pollen analysis of successive honeys has demonstrated the contamination of honey by pollen which is part of the bees diet. These phenomena, caused by the bees, would explain the presence in honey of species without floral nectaries and species which were no longer in bloom when the honey super was installed. Most of the plants selected by the bees were present within 500 m of the apiary, were selected from the indigenous or naturalised flora and were visited for both pollen and nectar (table V).
Key words: honey / pollen pellett / pollen analysis / nectar plant / pollen plant / Canada