Bumblebee

A bumblebee at work in a tomato flower in cool early-morning weather is doing something a honeybee cannot. The honeybee won’t fly until temperatures hit ~55°F; the bumblebee is out at 40°F. The honeybee can’t perform buzz pollination on tomato or eggplant flowers; the bumblebee vibrates the flower at the right frequency to shake pollen loose.

For several garden crops, the bumblebee isn’t an alternative to the honeybee. It’s the only effective pollinator.

What they pollinate (especially)

Crops that require buzz pollination (sonication) — honeybees cannot pollinate these effectively:

• Tomato
• Eggplant
• Pepper (most varieties)
• Blueberry
• Cranberry
• Kiwi
• Many wildflowers and native plants

Crops they pollinate well in cool weather — when honeybees aren’t flying:

• Early-spring fruit trees (apple, pear, plum, cherry)
• Cool-weather garden flowers and pollinator plants

Why they’re declining

Multiple causes documented:

• Habitat loss — disappearance of perennial borders, meadows, brush, and unmown edges
• Pesticides — particularly neonicotinoids; bumblebees are highly sensitive
• Pathogens — including Nosema bombi, partly spread by commercial bumblebee operations
• Climate change — montane species are running out of cooler elevations to retreat to
• Loss of nesting sites — most species nest in pre-existing cavities (rodent burrows, tussocks of grass, hollow logs); intensive land management eliminates these

Specific concerns: rusty-patched bumblebee (B. affinis) — listed as Endangered under the U.S. Endangered Species Act in 2017, the first bee species so listed. Once common across the eastern U.S., now extremely rare.

How to support them

• Plant for continuous bloom — bumblebee colonies need pollen and nectar from early spring (queen emergence) through fall (worker peak; new-queen production)
• Native flowering plants — bumblebees co-evolved with native plant communities; native plants generally provide much better nectar and pollen than ornamental hybrids
• Tubular and bell-shaped flowers — bumblebees have long tongues and forage in flower forms honeybees can’t access (penstemon, salvia, comfrey, lupine, foxglove, snapdragon, monkshood)
• Nesting habitat — unmown grass tussocks, brush piles, mouse-and-vole burrows left undisturbed, undisturbed corners
• No neonics — buy plants from nurseries that don’t use neonicotinoids; the chemical is systemic and persists in the plant tissues
• Tolerate some “messy” areas — bumblebee habitat is not tidy

How to identify them (briefly)

• Large, fuzzy body with dense hair
• Color patterns vary by species (black + yellow most common; some species have white, red, or orange bands)
• Slow, low flight compared to honeybees
• Solitary at first (queens in spring), then small colonies (workers in summer)

See also

Auto-generated from this entry’s typed relations: frontmatter, grouped by relation type so the editorial signal isn’t flattened.

• Enables: [[gardening]]
• Shares approach with: [[honeybee]]
• Member of: [[animal]]

Sources

• Xerces Society, Bumble Bees of North America (Princeton, 2014)
• USDA / U.S. Fish & Wildlife Service rusty-patched bumblebee documentation
• Bumble Bee Watch (citizen science database)

Rooted in life.