Long-horned bees are a genus of bees (Melissodes) that emerge from their nests in the summer months, typically starting in July and coinciding with the onset of flowering in their preferred forage plants: those in the Asteraceae family. These beautiful, robust, medium-size bees are effective pollinators of many open-flower forms, including sunflowers. The insect’s common name is derived from the unusually long antennae that most males sport. Females have long, pollen-collecting hairs on their hind legs that resemble saddle bags.

Many species in the genus are specialists, with the females collecting pollen from a narrow range of plants — in some cases from only a particular plant genus. By providing composite flowers (those in the Asteraceae family), including ones that specialists seek out, you can attract a variety of long-horned bees to your garden, no matter its size. Holm Design & Consulting LLC Family: Apidae
Subfamily: Apinae
Genus: Melissodes
Numbers: Approximately 97 species and 7 subgenera in North America (north of Mexico); 27 species east of the Mississippi
Distribution: Long-horned bees are found throughout North America and in 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. Holm Design & Consulting LLC When to look for them: Midsummer through fall is the optimum time to observe long-horned bees. Species in the genus are responsible for pollinating many plants in the Asteraceae family, including commercial sunflowers.

Some long-horned bee species are specialists, with females seeking out a narrow range of plants. See the sample plant list below for more information.

Shown: A two-spotted long-horned bee (Melissodes bimaculata) visiting common ironweed (Vernonia fasciculata) in late summer. Holm Design & Consulting LLC How They Help

Long-horned bees are effective pollinators, especially of plants in the Asteraceae family that flower from midsummer through fall. Their medium size and relatively hairy heads and thoraxes provide a lot of surface area on which pollen grains can attach.

Like all bees, long-horned bees need a continuous succession of flowers in the garden and a variety of flower forms and colors. Females expend a lot of energy during nest building and provisioning and thus require an ongoing supply of pollen and nectar to fuel their activities, as well as to provide food for their offspring.

Shown: A male long-horned bee visiting gray-headed coneflower (Ratibida pinnata); notice the extremely long antennae, characteristic of males. Debbie Ballentine How to Spot Long-Horned Bees

Adults: Long-horned bees vary in size; the smaller species are approximately ¼ inch (6.5 millimeters) long and the largest are 5/16 inch (8 millimeters) long. Adults have a compact shape with light brown, gray or gold hairs on the head and thorax; their abdomens often have pale bands in the middle of the abdominal segments.

A distinguishing feature in females is the extremely long pollen-collecting hairs on the hind legs.

Males have unusually long antennae and often a white or yellow patch on the face. They do not return to the natal nest after they leave; they spend their days as adults in the landscape. One common behavior of males is aggregating on foliage during the night. Clinging to blades of grass or other foliage with their mandibles, legs or both, the group will spend the night together. Gardeners or hikers often find these aggregations in the early morning when the bees are waiting to warm up with the first rays of the sun.

Babies (larvae): Larvae are grub-like and are pale yellow to cream in color. It’s uncommon to see larvae, as long-horned bees nest below ground.

Shown: A group of males clinging to foliage for the night.
Holm Design & Consulting LLC How to Lure Them

Besides providing a pesticide-free garden and continuous succession of flowering plants, you’ll need a place where long-horned bees can nest. All long-horned bees nest in the ground. Uncompacted bare soil is ideal. Nest construction typically begins midsummer, often when vegetation can obscure the nest entrance. It’s important to look for bees excavating nests and protect the site from disturbance.

Maintain a bee-safe yard. Do not use pesticides, especially insecticides, in the garden, particularly on flowering plants.

Shown: A female long-horned bee visits common ironweed, one of the plants sought out by specialist long-horned bees. Holm Design & Consulting LLC Forage plants for adults. Female long-horned bees demonstrate a preference for composite flowers for their pollen collection. Because some species are specialists, provide a number of different composite plants that flower during summer and fall, including specialist plants* if possible. Remember to select plants native to your area.

Sample plant list for adults:

• Summer: Gray-headed coneflower*(Ratibida pinnata), blackeyed 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

Browse native plants for your region

Shown: Melissodes desponsa visiting hoary vervain (Verbena stricta) for nectar; this long-horned bee is a pollen-collecting specialist of thistles (Cirsium spp.). Holm Design & Consulting LLC Life cycle. In the upper Midwest, Great Lakes and Northeast regions, long-horned bees emerge from the natal ground nest in summer and then go on to construct their own nests. Females emerge as adults, mate with males, then look for a site to begin construction.

Nests are usually solitary; they can occur in groups but are rarely communal (multiple females sharing a nest). The nest is excavated by the female. She lines the brood cells with a wax-like secretion from a gland located at the end of her abdomen. This provides waterproofing of the cell. Holm Design & Consulting LLC Females forage in the landscape, collecting pollen and nectar from flowers. These floral resources are combined to form a pollen ball (bee bread) when the female returns to the nest. When enough pollen and nectar have been collected for a given brood cell, the female lays an egg on the provisions and then caps the cell with soil. The capped brood cell is backfilled with soil, often using soil excavated for the next brood cell in the nest.

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