Bee diversity and flower visitation to the genus Agalinis (Orobanchaceae) in North America

• Published in: Arthropod-plant interactions 2024-02, Vol.18 (1), p.141-148
• Main Authors: Dieringer, Gregg, Cabrera Rodriguez, Leticia
• Format: Article
• Language: English
• Subjects: Agalinis; Bees; Behavioral Sciences; Biomedical and Life Sciences; Conservation status; Ecology; Entomology; Flowers; Flowers & plants; Foraging behavior; Geographical distribution; Geography; Grasslands; Habitat loss; Habitats; Invertebrates; Life Sciences; Natural populations; Original Paper; Orobanchaceae; Plant Pathology; Plant reproduction; Plant Sciences; Pollen; Pollination; Pollinators; Stamens; Taxa; Trichomes
• ISSN: 1872-8855; 1872-8847
• DOI: 10.1007/s11829-023-09999-0

Agalinis is a diverse and wide-ranging genus within the Orobanchaceae. Species may be either widespread or restricted in range. Natural populations tend to be small and isolated being distributed across natural grassland or open habitats that are frequently fragmented due to habitat loss. We ask whether patterns of distribution and limited occurrence may be related to visiting bee diversity. We conducted a review of the bee taxa recorded visiting flowers of the genus Agalinis involving 15 published surveys plus our own field observations. We assessed the association of visiting bee diversity on flower size, geographical distribution, regional distribution, and conservation status of 14 species of Agalinis. From a total of 160 floral records, we found 5 families, 18 genera and 58 bee taxa have been documented visiting flowers of Agalinis . Halictidae (43.1%) and Apidae (29.3%) constituted the largest proportion of bees. The number of bee taxa recorded for a species of Agalinis showed a significant positive relationship with geographic range across the United States and Canada. However, no differences in bee diversity at the level of family were noted for flower size, regional distribution or conservation status. Bee diversity patterns recorded to date suggest a generalized pollination system not associated with the limited distribution or small population sizes of many Agalinis species. Nevertheless, previous studies indicate a level of specialization with respect to flower form and bee foraging behavior. The gibbous to ventricose corolla, combined with dimorphic stamens bearing filament trichomes facilitate inverted bee foraging for pollen gathering.