Pest profile

Giant Resin Bee

Megachile sculpturalis · Hymenoptera: Megachilidae[2]

The giant resin bee nests in tunnels carpenter bees have already made, because it can't chew through wood itself.[1]

Giant resin bee, a large bee with a dark head, golden-haired thorax, black abdomen and smoky wings, on white flowers
Giant resin bee, a large bee with a dark head, golden-haired thorax, black abdomen and smoky wings, on white flowers. (c) Louise Woodrich, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Females are 22 to 27 mm, with a dark head and golden hairs on the thorax and first abdominal segment.[1]
  • Its smoky wings are often held in a V shape over the back.[1]

Look-alikes

Look-alikeHow to tell them apart
Other leafcutter beesMost are 5 to 24 mm, considerably smaller than the giant resin bee.[1]
Carpenter beeCarpenter bees chew nest tunnels in wood; the giant resin bee only reuses them.[1]

Where it lives

First found at U.S. ports in North Carolina in 1994, it now lives in most states east of the Mississippi.[1]

US map: public records from 34 states since 1990 (GBIF).

Biology and life cycle

It's solitary, though females often nest near each other, sealing brood cells with wood bits, mud or resin.[1]

It forages on many plants but prefers ones introduced from Asia.[1]

Damage and signs

  • It doesn't cause structural damage, but it displaces native carpenter bees from their tunnels.[1]

Health risk

UF/IFAS mentions no health risk; it's a solitary pollinator.[1]

Control

Keep them out

If control is needed, fill old carpenter bee holes with putty and paint wood so carpenter bees don't make new cavities.[1]

Common questions

Is the giant resin bee damaging my wood?
No; it can't chew wood and uses holes carpenter bees already made.[1]
Should I spray giant resin bees?
Aggressive chemical control isn't needed; changing their nesting habitat is recommended.[1]

Sources

  1. University of Florida IFAS Extension (Featured Creatures), “Giant Resin Bee, Megachile sculpturalis (EENY-733).” edis.ifas.ufl.edu/publication/IN1258 (accessed 2026-10-06)
  2. iNaturalist, “Megachile sculpturalis taxon page (order and family).” www.inaturalist.org/taxa/52785 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.