
Five different Andrena species
by Zabinski
Even though bees are the most frequently discussed pollinators we still do not know when many species are active in the environment or what flowers they have preferences for. Learning about the activity and flower visitations of native bee species can help scientists better understand what potential ecological roles species may be playing in their environment. This is especially true in the mega diverse group of bees known as mining bees, in the genus Andrena. Due to such diversity within Andrena (1,738 recognized species) taxonomists has further separated Andrena into different subgenera. The subgenus Plastandrena is an interesting group found throughout Europe, Asian, and North America. The North American Plastandrena include 5 recognized species: Andrena mellea, Andrena argemonis, Andrena crataegi, Andrena fracta, and Andrena prunorum with A. crataegi and A. prunorum being very commonly encountered species. An in-depth look at the monthly activity and flower visitations for these species has never been conducted.
To study this, I gathered all the monthly occurrence records and flower visitations records from online data repositories, other bee experts, publications, and identified more specimens with records in natural history museums. This allowed me to amass many records to observe what time of year each species is active. As well as the breadth of flower species and flower families each species visits. This information demonstrated that A. mellea and A. argemonis can be classified as polylectic (or generalist) bees that visit a variety of flower genera and families. While A. crataegi, A. fracta, and A. prunorum can be classified as highly polylectic species, that visit a large variety of different flower genera and families. Andrena argemonis was the most specialized species, showing preferences for flowers in the genus Argemone but still has been found on a variety of other flower genera. The overall approach of this research may be a way to utilize the vast amount of information on label data that is stored in natural history collections to help assess the potential flower preferences for native bees.
