Triepeolus concavus

(Cresson, 1878)

Concave Longhorn-Cuckoo

Triepeolus concavus is a cleptoparasitic in the Apidae. Females lay in the ground nests of bees, particularly sunflower bees (Svastra obliqua expurgata). The lacks pollen-collecting structures (scopa) and relies on stealing food stores provisioned by host bees. It is found in the United States and Mexico.

Triepeolus concavus by (c) Christine Melvin, some rights reserved (CC BY), uploaded by Christine Melvin. Used under a CC-BY license.

Triepeolus concavus, M, back, Dorchester Co, MD 2015-09-01-11.47.37 ZS PMax UDR (21443561405) by USGS Bee Inventory and Monitoring Lab from Beltsville, Maryland, USA. Used under a Public domain license.

Triepeolus concavus, f, back, Pennington Co, South Dakota 2016-01-20-09.37 (32050876570) by USGS Bee Inventory and Monitoring Lab from Beltsville, Maryland, USA. Used under a Public domain license.

Pronunciation

How to pronounce Triepeolus concavus: /traɪˈɛpɪələs kɒnˈkeɪvəs/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from other Triepeolus by specific morphological features; the specific epithet "concavus" likely refers to a concave structural characteristic. Lacks pollen-collecting structures, distinguishing it from non-parasitic bees. Similar to other Epeolini tribe members but with species-specific diagnostic traits.

Images

Appearance

A cuckoo bee with typical longhorn-cuckoo . Males have been observed with long . Lacks scopa (pollen-collecting hairs) on the hind legs, a characteristic of cleptoparasitic bees.

Habitat

Associated with ground-nesting , particularly areas where sunflower bees (Svastra) nest. Observed in urban environments including downtown Davis, California, where host nesting occur in wood chip mulch and bare ground.

Distribution

United States and Mexico. GBIF records indicate presence in Middle America and North America. Documented in California, specifically in Yolo County.

Seasonality

active in summer. Larvae develop underground and emerge the following summer to build nests.

Host Associations

Svastra obliqua expurgata - kleptoparasiteFemale T. concavus lays in ground nests of this sunflower bee; larvae consume 's pollen stores and kill host larvae

Life Cycle

Females deposit in nests. Larvae hatch and consume the pollen ball collected by the host, then kill and eat the host larvae. Development occurs underground; emerge the following summer.

Behavior

Females are that enter nests to deposit . They wait near nest entrances for host bees to leave before entering. Males have been observed visiting flowers, including blanket flower (Gaillardia).

Ecological Role

Acts as a kleptoparasite on ground-nesting bees, specifically sunflower bees. Represents a natural control mechanism within native .

Human Relevance

Occasionally encountered in urban settings where bees nest, such as near buildings and parking lots. Misidentified by the public as , leading to unnecessary concern. Educational signage has been used to promote conservation.

Similar Taxa

Triepeolus punctoclypeusCongeneric in the same , distinguished by specific epithet referring to punctate
Epeolus speciesRelated in tribe Epeolini; T. concavus was historically associated with Epeolus and may be confused with members of that genus

Misconceptions

Public often mistakes this for a due to its and appearance, leading to calls for extermination. It is a native, beneficial insect that poses minimal sting risk.

More Details

Conservation Status

Not formally assessed; dependent on for survival

Research Significance

Documented in UC Davis research on native and hedgerow restoration; used in public education about native bee diversity