Ceratina strenua

Small Carpenter Bee
Ceratina strenua

Small Carpenter Bee Ceratina strenua female on Aster. October 28, 2009. Wheatley, Ontario. White streak on front shin.
Small Carpenter Bee Ceratina strenua female on Aster. October 28, 2009. Wheatley, Ontario. White streak on front shin.

Identification:
Female:
Head: Blue-green with an oblong whitish mark on lower face (clypeus). Mandibles slightly reddish with 3 teeth at tip.
Antenna: Dark, tips brownish. Segments 2 to 5 wider than long.
Thorax: More greenish than face. Thorax sides only have short, pale hairs. Tubercle whitish-yellow entirely.
Wings: Wing knobs pale yellowish-brown. Wings slightly tinted, veins brownish-yellow.

Small Carpenter Bee Ceratina strenua female on Ironweed. August 25, 2006, Wheatley, Ontario. Close-up front shin (tibia) with white streak.
Small Carpenter Bee Ceratina strenua female on Ironweed. August 25, 2006, Wheatley, Ontario. Close-up front shin (tibia) with white streak.

Legs: Black with metallic reflections. Short, pale hairs on legs. Front thigh (femur) has white dot at tip (knee). Main ID: Front shin (tibia) also has whitish spot or streak at base of segment. Feet reddish-brown.
Abdomen: Bluish-green with pale, short thin hairs on last two segments. Tip sharply pointed, no hair.

Male: Brassy-green
Head: Olive-green with a white 3 pointed mark on lower face (clypeus), hat-like; the points are all the same size. Another squarish, smaller white spot on mouth (labrum). Mandibles dark.
Antenna: Black, orange-brown on underside. Segments 2 and 3 wider than long.
Thorax: Thorax has 3 to 5 longitudinal lines on segment 1 (scutum). Thorax sides only slightly hairy. Tubercle entirely white.
Wings: Wing knobs pale brownish-yellow. Wings clear, iridescent. Veins brownish-yellow.

Small Carpenter Bee Ceratina strenua male on non-native bulb flower. March 25, 2012. Wheatley, Ontario. Thicker white streak on front shin.
Small Carpenter Bee Ceratina strenua male on non-native bulb flower. March 25, 2012. Wheatley, Ontario. Thicker white streak on front shin.

Legs: Black with metallic reflections. Front thigh (femur) has white dot at tip (knee). Main ID: Front shin (tibia) has white streak to almost entire length of shin. Feet brownish-red.
Abdomen: Brassy-green. Tip projecting, more rounded than female (sub-truncate), with a brush of light hairs.

Similar Species: C. strenua is the smallest, and darkest of the 4 species in Ontario. C. calcarata, C. mikmaqi and C. dupla do not have a white stripe on front shin (tibia).

Size: Female 5 mm – very small. Male 4.5 mm

Habitat: Forest edges and meadows.

Food: Nectar and pollen from a variety of flowers.

Flight Time: March to October

Life Cycle: Females bore tunnels twigs like raspberry, roses and thistle for nesting. Females stay in nest until new batch of adults emerge from their eggs.

Comments: Rare. Essex County – photos. Also Niagara. Southern Ontario is the northern extent of their range.

For information on synonyms, references and type specimens see next page

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