Phenology of the specialist bee Colletes hederae and its dependence on Hedera helix L. in comparison to a generalist, Apis mellifera

Abstract Colletes hederae, the ivy bee, (Hymenoptera: Colletidae) has undergone large range expansions in Europe recent years, including colonising Britain 2001 with its original distribution limited to Western mainland and Channel Islands. It is thought specialise on Hedera helix L. (Apiales: Ariliaceae), common ivy. However, some research questioned this dependence. This study quantifies foraging ecology of C. hederae determine relationship Sussex. We quantified phenology bloom, activity flower visitation, pollen collection females through analysis. also gathered equivalent data Apis mellifera both as a comparison assess alternative sources. The female was highly correlated phonologically contained within bloom period. Pollen analysis from identified 98.5% samples, significantly more than for A. (90%). Two other plant species were samples when not at peak. Surveys flowers surrounding aggregations found that most insect (26%) . Although can forage species, be an important floral resource. results suggest potential competition , only bee present small numbers H. flowers, although generalist, autumn it mainly forages