Mason Bees
Osmia spp.
Megachilidae · Genus Osmia
Small metallic blue-black solitary bees that pollinate spring fruit trees more efficiently than any other insect on the continent. One female mason bee does the work of 120 honey bees on apple flowers.
How to spot one.
Small (0.3–0.5 inch)
Metallic blue-black or blue-green sheen
Carries pollen on the underside of the abdomen — not on the legs
Slow, hovering flight
How it lives.
Solitary cavity-nesters. Uses existing holes — hollow stems, beetle borings, purpose-built bee hotels — and seals each nest cell with mud (hence 'mason'). No honey, no queen, no defensive stinging.
The spec sheet.
- Type
- Bee
- Active
- April – June
- Native to NJ
- Yes
- Conservation status
- stable
- Family
- Megachilidae · Genus Osmia
Notable species.
Species you’re most likely to see, plus any of conservation concern.
Blue Orchard Mason Bee
Osmia lignaria
Native fruit tree specialist — commercially important
What it needs.
Plants this species visits, feeds on, or depends on. Names in hydrangea link to the plant’s Field Guide entry.
Apples, pears, cherries, plums
Primary pollinator
Primary pollinator
Nectar source
Nectar source
Xerces Society · Rutgers NJAES
Others in this group.
- BsBeeNative · NJ
Bumble Bees
Bombus spp.
Big, fuzzy, striped, social bees — the ones everyone recognizes. Bumble bees are the most efficient pollinators in New Jersey and the only bees here t…
- AsBeeNative · NJ
Mining Bees
Andrena spp.
The first bees on the wing each year. Mining bees are solitary ground-nesters that emerge in March and April — often while the ground is still cold —…
- H&BeeNative · NJ
Sweat Bees
Halictus & Lasioglossum spp.
The smallest native bees in New Jersey — often under half an inch — and among the most abundant. Named for their attraction to human perspiration (a s…