Identification: Female entirely red, without yellow marks. Male antenna unique colour combination: dark, light, dark, tip light.
Head: Dark red with short silvery-white hair. Top of head has a dark spot extending down to the base of the antenna. Mandibles toothless. Cheeks half as wide as eye width.
Antenna: Base (scape) bright dark red, underside blackish. Segments dark rusty red to brown-black, lighter on underside. All segments the same size.
Thorax: Dark red. Collar dark red, with black at each side edge. Segment 1 (scutum) has a faint black median line. Segment 2 (scutellum) has slightly projecting knobs light rusty red. Segment 3 (propodeum) mostly black, sides with dense silvery-white hair. Thorax front half dark red, rest black; covered with silvery-white hair. Tubercles reddish-yellow.
Wings: Wing knobs (tegulae) reddish-yellow. Wings slightly tinted, clear spot before tips. Tips dark.
Legs: Brownish-yellow with blackish streaks, more so on underside.
Abdomen: Bright dark red, smooth and shiny. Segment 1 black at base. No other marks on abdomen. Tip very short with tufts of silver hair.
Similar Species: Female is same bright dark red as female Nomada pygmaea, but without yellow spots on abdomen. Females fly low to the ground and are never still. Almost impossible to photograph.
Head: Upper face black. Lower face light yellow, including mandibles (tips dark), without teeth. Yellow continues up inner eye margin to just above antenna bases. Cheeks black, as wide as eye width.
Antenna: Base (scape) swollen, dark on top side, yellow on underside. Segment colors unique: 1 to 3 or 4 dark, segments 3 or 4 to 7 light, segments 8 to 10 dark, tips light. Underside of antenna light brownish-yellow.
Thorax: Dark rusty brown. Collar with narrow yellow stripe. Segment 1 (scutum) dark rusty brown. Segment 2 (scutellum) has brighter rusty red, slightly raised knobs. Segment 3 (propodeum) has silvery hair at side edges. Thorax side darker to blackish, covered with silvery hair. Tubercles are light rusty red. Another small yellowish spot and 2nd small yellow spot side by side near hind leg joint are barely visible.
Wings: Wing knobs (tegulae) light rusty red. Wings tinted, clear spot before tips, veins light rusty red.
Legs: Base of thighs (femora) and trochanters dark, covered with silvery hairs. Front and middle leg light rusty red, hind leg darker. All shins (tibiae) have yellowish-brown pile. Hind thigh curved.
Abdomen: Rusty red, with varying amounts of black, usually at very base or end of segments.
Segment 1 medium to tiny yellow spot on each side.
Segment 2 large oval patch on each side, with a pointed area toward centre.
Segments 3 to 6, yellow stripes across segment; segment 3 interrupted or not at centre.
Tip rusty red, slightly bi-lobed.
Underside entirely rusty red, light-colored hairs on segments 4 to end.
Size: Female 8.5 mm. Male 8.5 to 9.5 mm
Habitat: Forest edges and meadows.
Food: Flower nectar such as Dewberry and Black-eyed-Susan.
Flight Time: May and June in Essex County. April to August in Ontario.
Life Cycle: A cleptoparasite of Metallic Green Bees Agapostemon virescens, A. sericeus and Mining Bee Andrena alleghaniensis.
“The female cuckoo bees normally visit the Agapostemon nesting area once or twice during the time of day that they are active, staying for between 14 and 45 minutes and making repeated attempts to enter host burrows. They fly around the burrow area a few centimetres above the ground and alight on a suitable perch a short distance from a nest entrance. For anything between 5 seconds and 10 minutes, they sit facing the burrow entrance, with their antennae directed towards it, before they make any attempt to enter. Of attempts to enter the nest burrow, 50% are made after the host has left on a foraging trip; otherwise they are made just after the host has entered the burrow or when there is no visible activity at the nest entrance. At no time do N. articulata females attempt to enter when the host is at the nest entrance. Having decided to investigate a burrow, the female cuckoo bee advances towards it with her wings vibrating. At the burrow entrance, she stops and then inserts her antennae into it for 1 to 2 seconds, her wings still vibrating. The wing-vibrating then ceases and she walks into the burrow to lay her eggs.” per Rod Preston-Mafham, Encyclopedia of Land Invertebrate Behavior, 1993, pg. 154.
Comments: Essex County per photos– not on any list. Kent County – Rondeau Provincial Park species list. Toronto, Peel County, Niagara, Long Point. Also in Southern Michigan (Livingston County).
For information on synonyms, references and type specimens see next page