Spotlight on Long-Horned Bees: Summer's Essential Pollinators

Long-horned bees (Melissodes) emerge from their underground nests in midsummer, typically July, just as their favorite forage plants — members of the Asteraceae family — begin to flower. These robust, medium-sized bees are striking pollinators of open-faced blooms like sunflowers. Their common name comes from the males' extraordinarily long antennae, while females sport dense, pollen-collecting hairs on their hind legs that resemble saddlebags.

Many Melissodes species are specialists, with females gathering pollen from a narrow range of plants, sometimes just a single genus. By planting a variety of composite flowers (Asteraceae), including specialist host plants, you can attract a diverse community of long-horned bees to gardens of any size.

Family: Apidae
Subfamily: Apinae
Genus: Melissodes
Species Count: Approximately 97 species and 7 subgenera in North America (north of Mexico); 27 species east of the Mississippi
Distribution: Throughout North America and parts of Central and South America
Habitat: Woodland edges, gardens, meadows, prairies, and old fields

Shown: A female long-horned bee on wild quinine (Parthenium integrifolium); note the long, pollen-collecting hairs on the hind legs.

When to Observe Them

Midsummer through fall is prime time for watching long-horned bees. These bees are key pollinators for many Asteraceae plants, including commercial sunflowers. Because some species are specialists, providing a range of composite flowers ensures you support both generalists and specialists.

Shown: A two-spotted long-horned bee (Melissodes bimaculata) visiting common ironweed (Vernonia fasciculata) in late summer.

Why They Matter

Long-horned bees are highly effective pollinators, especially for Asteraceae flowers blooming from midsummer into fall. Their medium size and hairy heads and thoraxes provide ample surface area for pollen transfer. Like all bees, they need a continuous succession of diverse flowers. Females expend significant energy building and provisioning nests, requiring a steady supply of pollen and nectar for themselves and their offspring.

Shown: A male long-horned bee on gray-headed coneflower (Ratibida pinnata); notice the extremely long antennae characteristic of males.

How to Identify Long-Horned Bees

Adults

Size varies: smaller species are about ¼ inch (6.5 mm) long, while the largest reach 5/16 inch (8 mm). They have a compact build with light brown, gray, or gold hairs on the head and thorax; abdomens often display pale bands mid-segment.

A key female trait is the exceptionally long pollen-collecting hairs on the hind legs. Males have remarkably long antennae and often a white or yellow facial patch. After leaving the natal nest, males do not return; they spend their adult days in the landscape. A notable behavior: males aggregate on foliage at night, clinging to grass blades or leaves with mandibles and legs. Gardeners and hikers often discover these clusters in early morning as bees warm up in the first sunlight.

Larvae

Larvae are grub-like, pale yellow to cream-colored. They are rarely seen because long-horned bees nest underground.

Shown: A group of males clinging to foliage overnight.

How to Attract Them

Beyond a pesticide-free garden with continuous bloom, you must provide nesting habitat. All long-horned bees nest in the ground, preferring uncompacted bare soil. Nest construction begins in midsummer, often hidden by vegetation. Watch for bees excavating nests and protect those sites from disturbance.

Maintain a Bee-Safe Yard

Avoid pesticides, especially insecticides, on flowering plants.

Shown: A female long-horned bee visits common ironweed, a plant sought by specialist long-horned bees.

Forage Plants for Adults

Female long-horned bees prefer composite flowers for pollen collection. Because some species are specialists, include a variety of summer- and fall-blooming composites, incorporating specialist plants where possible. Choose species native to your region.

Sample Plant List for Adults:

• Summer: Gray-headed coneflower* (Ratibida pinnata), black-eyed Susan* (Rudbeckia spp.), purple coneflower (Echinacea spp.), tickseed* (Coreopsis spp.), ironweed* (Vernonia spp.), thistles* (Cirsium spp.), smooth oxeye (Heliopsis helianthoides), spotted beebalm (Monarda punctata), vervains (Verbena spp.), joe pye weed (Eutrochium spp.), and sunflowers* (Helianthus spp.)
• Late Summer and Fall: Goldenrod* (Solidago spp.), common boneset (Eupatorium perfoliatum), and asters* (any species)

*Indicates a specialist plant

Shown: Melissodes desponsa visiting hoary vervain (Verbena stricta) for nectar; this species is a pollen-collecting specialist of thistles (Cirsium spp.).

Life Cycle

In the upper Midwest, Great Lakes, and Northeast, long-horned bees emerge from natal ground nests in summer and build their own. Females emerge, mate, then seek a nest site. Nests are usually solitary, sometimes occurring in groups but rarely communal. The female excavates the nest, lining brood cells with a wax-like secretion from an abdominal gland for waterproofing.

She forages for pollen and nectar, combining them into a pollen ball (bee bread) back at the nest. Once a cell is provisioned, she lays an egg on the food mass, caps the cell with soil, and backfills it — often using soil from the next cell's excavation.

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