Heimbra opaca

(Ashmead, 1894)

Heimbra opaca is a of chalcid in the Eurytomidae, first described by Ashmead in 1894. Originally placed in the Euperilampus, it was later transferred to Heimbra. This small parasitic wasp belongs to a family known for attacking various insect , though specific biological details for this species remain poorly documented. The species has been recorded from Brazil.

Pronunciation

How to pronounce Heimbra opaca: /ˈhaɪmbrə oʊˈpækə/

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Identification

Identification to level requires examination of microscopic morphological characters, including details of , wing venation, and genitalia. The Heimbra is distinguished from related eurytomid genera by specific structural features of the and mesosoma. Heimbra opaca can be separated from its Heimbra nigra (the only other species in the genus) by subtle differences in coloration and body proportions, though precise diagnostic characters are not readily available in general literature. Specimens should be compared with type material or authoritative determinations for reliable identification.

Appearance

As a member of Eurytomidae, Heimbra opaca is a minute , likely measuring only a few millimeters in length. Eurytomid wasps typically exhibit reduced wing venation, a compact body form, and relatively short . The epithet 'opaca' (meaning dull or opaque) suggests a non-metallic, matte coloration rather than the bright metallic greens or blues seen in some related chalcidoids. Specific morphological details for this species are not well documented in accessible literature.

Distribution

Documented from Brazil, with specific records from the Federal District (BR-DF) and Goiás (BR-GO). The full extent of its range within South America remains uncertain due to limited collecting and documentation.

Ecological Role

As a member of Eurytomidae, Heimbra opaca likely functions as a of other insects. Eurytomid wasps as a attack a diverse range of including gall-forming insects, seed-feeding beetles, and other hymenopterans. The specific host relationships of Heimbra opaca have not been documented.

Similar Taxa

Heimbra nigraThe only other in the Heimbra; distinguished by differences in coloration and body proportions, though specific characters require detailed examination
Other EurytomidaeNumerous small chalcid wasps in related share the general body plan and reduced wing venation; definitive separation requires examination of antennal segmentation, mesosomal structure, and other microscopic features

More Details

Taxonomic History

First described by William H. Ashmead in 1894 as Euperilampus opacus, this was later transferred to the Heimbra. The original spelling 'opacus' was Latinized to 'opaca' in some subsequent treatments, creating the synonym Heimbra opacas. The genus Heimbra was established to accommodate species with distinctive morphological features separating them from the broader Euperilampus group.

Data Deficiency

This is extremely poorly known, with only 4 observations recorded in iNaturalist and minimal published biological information. The original description and any subsequent taxonomic revisions are not readily accessible in major databases, reflecting the broader neglect of small parasitic in entomological research.