Brachymeria tegularis
(Cresson, 1872)
Brachymeria tegularis is a small parasitic wasp in the Chalcididae, originally described from North America by Cresson in 1872. The Brachymeria comprises approximately 26 in North America, with members typically ranging 3-6 mm in length. Species in this genus function as both primary and secondary , attacking larvae of Lepidoptera and muscoid flies, with emerging from pupae. The distinctive 'thunder thighs'—greatly swollen hind with bowed tibiae—are characteristic of the family and aid in rapid escape from danger.
Pronunciation
How to pronounce Brachymeria tegularis: /ˌbrækɪˈmɪəriə tɛɡjʊˈlɑːrɪs/
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Identification
Distinguished from other chalcidid by the greatly swollen hind with bowed tibiae. Separation from other Brachymeria requires examination of specific morphological characters not detailed in general sources; B. tegularis is one of 26 North American species in the genus. The specific epithet 'tegularis' (meaning 'of small shields') may refer to particular thoracic or abdominal patterns, but distinguishing features from are not documented in available literature.
Appearance
Small , 3-6 mm in length, with compact, heavily armored body typical of Chalcididae. Hind greatly enlarged and swollen ('thunder thighs'), with hind tibiae bowed to fit the curvature of the preceding leg segment. Body coloration and specific markings for B. tegularis not separately documented from in available sources.
Habitat
have been observed in association with colonies where they feed on honeydew, and seeking shade in hot conditions among vegetation such as cattails or shaded cottonwood leaves near artificial wetlands. Adults occasionally visit flowers including wild carrot (Daucus carota). larval include pupae of Lepidoptera and muscoid flies.
Distribution
Recorded from Canada: Alberta, British Columbia, Manitoba, and Ontario. Distribution in the United States not explicitly documented in available sources, though the occurs throughout North America.
Diet
feed on honeydew from aphids and nectar from flowers such as wild carrot (Daucus carota). Larvae are developing within larvae.
Life Cycle
Females use their ovipositor to inject into larvae. Multiple eggs may be deposited in a single host, but typically only one larval offspring matures and emerges from the host pupa. Developmental period from egg hatch to is approximately 20-27 days under favorable conditions; may require 155-180 days.
Behavior
occasionally 'play possum'—hugging legs to body and remaining motionless when disturbed. Males have been observed defending territories around nectar sources where females forage.
Ecological Role
Primary and secondary of Lepidoptera and muscoid fly larvae. Some in the have been reared from grasshoppers, though likely as parasitoids of tachinid or sarcophagid flies that themselves parasitized the grasshoppers. Potentially important in regulating of blow flies, flesh flies, and pest caterpillars.
Human Relevance
Similar Taxa
- Brachymeria fonscolombeiCommon holarctic with similar and ; B. tegularis distinguished by specific morphological characters and distribution pattern
- Other Chalcididae generaShare characteristics of enlarged hind , but differ in specific femoral and tibial proportions, body shape, and wing venation
More Details
Taxonomic history
Originally described as Chalcis tegularis by Cresson in 1872, later transferred to Brachymeria. The Brachymeria was established by Westwood in 1829.