Pest profile

Squash Bees

Xenoglossa pruinosa (also listed as Eucera or Peponapis pruinosa) · Hymenoptera: Apidae[3]

Squash bees are native, solitary, ground-nesting bees that collect pollen only from squash, pumpkins, zucchini and gourds, and they start visiting the flowers around sunrise, before other bees are active.[1][2]

Squash bee on the stamen of an open yellow squash flower
Squash bee on the stamen of an open yellow squash flower. (c) Frances Oliver, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • They resemble honey bees but are larger and bulkier, with longer antennae and rounder faces; Oregon State describes them as hairy honeybee look-alikes with well-defined white bands on the abdomen.[1][2]
  • Females have very fuzzy hind legs that may be covered all over in loose pollen, and males have a yellow spot on the face.[1]

Look-alikes

Look-alikeHow to tell them apart
Honey beeSmaller and less bulky; worker honey bees pack pollen into compact balls on smooth, flat hind legs.[1]

Where it lives

They occur throughout much of the United States and Mexico; Oregon State reports the first record in Oregon, in the southern part of the state, in 2016.[1][2]

US map: public records from 33 states since 1990 (GBIF).

Biology and life cycle

Each female digs her own nest in the soil, usually building nest cells 6 to 12 inches underground, often right under the squash plants.[1]

In North Carolina, adults are active from June to August; the rest of the year the next generation develops sealed in the nest cells.[1]

They forage from dawn until the squash flowers close around midday.[1][2]

Damage and signs

  • They do no damage; squash depends on insect pollinators because male and female flower parts are in separate flowers, and 6 to 10 squash-bee visits fully pollinate a female flower.[1]
  • By some estimates, squash bees pollinate around two-thirds of the squash grown commercially in the United States.[1]

Health risk

They are solitary bees that don't live in a hive or colony; neither source reports a stinging problem.[1][2]

Control

Prevention

Tilling a squash bed at any time of year can destroy nests; one farm census found three times more squash bees on no-till farms, though a second study found no such effect.[1]

If you must treat flowering squash for pests, check the label for pollinator warnings; some insecticides should not be used at all, and others only in the evening when bees aren't active.[1]

Systemic insecticides applied before flowering can still reach toxic levels in squash pollen; one study found an 89 percent drop in squash bee reproduction where squash was drenched with imidacloprid.[1]

Common questions

Is the bee in my squash flower a honey bee?
It may be a squash bee, which is larger and bulkier with longer antennae and a rounder face.[1][2]
Why do I only see squash bees early in the morning?
Squash flowers open at dawn and close around midday, and squash bees forage on that schedule.[1][2]
Does tilling harm squash bees?
It can; they nest 6 to 12 inches underground, often under the squash plants, though studies disagree on how much tilling matters.[1]

Sources

  1. NC State Extension, “Squash Bees in the Home Garden.” content.ces.ncsu.edu/squash-bees-in-the-home-garden (accessed 2026-10-15)
  2. Oregon State University Extension Service, “Squash bees (published August 2020, reviewed 2024).” extension.oregonstate.edu/catalog/squash-bees (accessed 2026-10-15)
  3. iNaturalist, “Xenoglossa pruinosa taxon page (order and family).” www.inaturalist.org/taxa/1594041 (accessed 2026-10-06)

Updated 2026-10-15. Built from sourced records. Spot an error? Tell us.