Chelonus

Jurine, 1807

Chelonus is a of parasitic in the Braconidae, Cheloninae. These wasps are internal of larvae, particularly those in superfamilies Tortricoidea and Pyraloidea. The genus contains approximately 139 in North America north of Mexico. Chelonus wasps exhibit a distinctive abdominal structure where the first three segments are into a single plate, making them relatively easy to identify among braconids.

Chelonus by (c) Elliott Gordon, some rights reserved (CC BY), uploaded by Elliott Gordon. Used under a CC-BY license.Chelonus clypealis by the Smithsonian. Used under a CC0 license.Chelonus (Microchelonus) salicis by the Smithsonian. Used under a CC0 license.

Pronunciation

How to pronounce Chelonus: /ˈkɛləˌnʊs/

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Identification

Chelonus can be distinguished from other braconid wasps by the first three urotergites ( abdominal segments), creating the appearance of a single-segmented . The side of the abdomen retains more normal segmentation. This contrasts with most other braconids and ichneumon wasps, which have clearly segmented abdomens. Wing venation also differs from ichneumon wasps. Members of this are small, averaging around 5 mm in length, with a robust build.

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Habitat

Found in diverse environments where occur. frequently observed on late summer and fall flowers such as wild carrot, where they search for host .

Distribution

Widespread in North America with approximately 139 recorded north of Mexico. Distribution records from GBIF include Denmark and Norway, suggesting Holarctic distribution.

Seasonality

active in late summer and fall, coinciding with flowering periods of plants such as wild carrot.

Host Associations

Life Cycle

Females use a hair-like ovipositor to insert directly into eggs. The larva hatches but remains in its first instar while the host caterpillar matures. Development resumes only when the host prepares to pupate or spin a cocoon, at which point the wasp larva consumes the host. At least one documented case exists where altered host timing, causing premature attempt.

Behavior

Females search flowers for that have been deposited in plant tissue. The larva exhibits developmental arrest, remaining during host growth before resuming development at host .

Ecological Role

agent of pests, particularly pyralid and tortricid moths. Some used in management of agricultural pests such as the .

Human Relevance

Some studied for potential against crop pests. Chelonus phthorimaeae and C. kellieae have been investigated for management of (Phthorimaea operculella).

Similar Taxa

  • IchneumonidaeSimilar general appearance but distinguished by wing venation and abdominal structure; Cheloninae have abdominal segments not seen in ichneumonids
  • Other BraconidaeMost other braconids have clearly segmented rather than the single-plate appearance of Cheloninae

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