Insect pollinators of Denali National Park and Preserve: A survey of bees (Hymenoptera: Anthophila) and flower flies (Diptera: Syrphidae)

Rykken, Jessica

Insect pollinators, specifically bees (Hymenoptera: Anthophila) and flower flies (Diptera: Syrphidae), are critical to maintaining healthy plant communities and functioning ecosystems in Denali National Park and Preserve. Despite their ecological importance and potential vulnerability to environmental threats such as climate change, the diversity of these pollinators has remained largely unknown to park scientists and managers. In an effort to establish a pollinator database, I conducted a survey in 2012 with three main objectives: (1) to document bee and flower fly diversity and distribution across selected areas of the park; (2) to provide information on habitat and plant community associations for individual species; and (3) to engage in outreach activities and create educational products to inform park staff and visitors about insect pollinators. In 2012, between June 21 and July 22, I used an insect net, bee bowls, and vane traps to collect bees and flower flies at 57 sites along the Denali Park Road. Sites were located between the eastern park entrance and Kantishna, approximately 148 km to the west; elevations ranged from 472 to 1480 m. I targeted early successional habitats, including gravel bars, and areas of high plant diversity, such as alpine tundra. A cooler and wetter than average growing season resulted in low pollinator activity. In all, I collected 552 bees comprising 20 species; the vast majority of bee specimens were bumble bees (Bombus; 502 specimens, 13 species). Flower flies were comparatively more diverse (42 species) even though fewer specimens (328) were collected. While many generalist pollinator species were collected in multiple habitats at various elevations, some species were primarily associated with lower or higher elevations (e.g., all solitary bees were collected down near the park entrance). Of special note, a flower fly species new to science in the genus Cheilosia was found near the East Fork cabin. I also documented the presence of the bumble bee, Bombus occidentalis, in the park, a western species that has been in drastic decline in the southern portion of its North American range. Park visitors and staff learned more about Denali’s pollinators through activities such as a Denali-ology seminar, slide presentations, and weekly “open house with a researcher” sessions in the Murie Science and Learning Center. Pollinator fact sheets and website content are also in production for educating various audiences.

Insect pollinators of Denali National Park and Preserve: A survey of bees (Hymenoptera: Anthophila) and flower flies (Diptera: Syrphidae)

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