Lunate longhorn-cuckoo bee (Triepeolus lunatus)

Apidae > Triepeolus > Triepeolus lunatus

Lunate longhorn-cuckoo (Triepeolus lunatus) is a distinctive cuckoo bee of agricultural fields, gardens, and cities. It is active in summer, well-timed to co-occur with its presumed eucerine host Melissodes bimaculatus. T. lunatus has a preference for nectar from summer-blooming Asteraceae in the garden like black-eyed susans (Rudbeckia) and coneflowers (Echinacea).


Summer, July-August; well-timed with summer Melissodes.


Widespread but generally uncommon throughout northeast. Usually present alongside Melissodes hosts, likely M. bimaculatus.


Size ≈ honey bee

Females largely hairless; black thorax with thin, incomplete ring of yellow hair; pattern on thorax resembling a “smiley face”; distinctive pattern on T1-T2: T1 has a black triangle rimmed by yellow and T2 is a wide black band.

Males like females.

Similar species

  • Triepeolus remigatus is similar but has thicker, complete ring of yellow around thorax, a distinctive anchor pattern on thorax, and a black band on T2 that is pinched at the edges of the abdomen.


Presumed cleptoparasite of M. bimaculatus and possibly other Melissodes. The nesting biology of this species and its host(s) is poorly understood.


Apparent preference for garden Asteraceae like Cosmos, sunflowers (Helianthus), coneflower (Echinacea), and black-eyed susans (Rudbeckia). Also visits mints like oregano (Origanum). Known to sleep in gardens by holding on to leaves and stems by their mandibles.

Natural Enemies

Unknown whether there are predators of T. lunatus; if so, they would likely also be non-bee predators of M. bimaculatus.

Page last updated:
January 17, 2023