Collyria
Schiødte, 1839
Species Guides
1Collyria is a of ichneumonid wasps in the Collyriinae. within this genus are specialized of stem sawflies (Cephidae), particularly those infesting cereal crops such as wheat. The genus includes species that have been investigated and employed as agents against wheat stem sawfly pests in North America and Europe. Members exhibit phenological synchrony with their , with typically emerging earlier than host , and demonstrate complex host discrimination including variable rates.
Pronunciation
How to pronounce Collyria: /kəˈlɪriə/
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Identification
Collyria can be distinguished from other ichneumonid of stem sawflies by their placement in the Collyriinae. Specific morphological characters distinguishing Collyria from related are not detailed in the provided sources. Identification to species level requires examination of detailed morphological features not summarized here.
Images
Habitat
Agricultural fields, particularly wheat and other cereal crop systems where (Cephidae) occur. Associated with wheat stubble and stems where host larvae develop and overwinter.
Distribution
Native to Europe (including England, Scandinavia: Denmark, Norway, Sweden) and Central Ciscaucasia (Russia). Introduced to North America (Canada: Ontario, Prairie Provinces; United States: western Montana considered as potential release area) as agent. One (C. catoptron) native to China.
Seasonality
emerge in summer, typically earlier than . Oviposition period coincides with availability of host and young larvae. Host larvae hibernate at base of wheat stems through winter, with development continuing within.
Host Associations
- Cephus pygmaeus - European wheat stem sawfly; primary for C. calcitrator
- Cephus cinctus - North American wheat stem sawfly; target of introductions
- Cephus fumipennis - Chinese wheat stem sawfly; of C. catoptron, evaluated for control of C. cinctus
- Cephus (Trachelus) tabidus - Additional for C. calcitrator
Life Cycle
-larval : eggs deposited into eggs or young larvae, with development continuing through host larval stages. Host larvae overwinter at base of wheat stems with parasitoids inside. Single parasitoid develops per host (solitary parasitoid). emerge from host cocoons or pupal chambers.
Behavior
Females discriminate between healthy and parasitized , with probability of (oviposition into already parasitized hosts) varying with proportion of parasitized hosts in . Superparasitism increases under host scarcity conditions. Only one individual successfully develops per host, with larvae perishing.
Ecological Role
Specialized regulating of pests in cereal agroecosystems. Acts as agent reducing damage to wheat crops. Competes with other parasitoid such as Pediobius beneficus (formerly Pleurotropis benefica), which is intrinsically inferior competitor.
Human Relevance
Employed in programs against wheat stem sawflies (Cephus cinctus in North America, C. pygmaeus in Ontario). Imported from Europe to Canada (1930–1939) and released in Prairie Provinces and Ontario. C. catoptron from China evaluated for potential release against C. cinctus in western Montana. Reduces economic damage to wheat production.
Similar Taxa
- Pediobius beneficusAlso parasitizes Cephus ; formerly classified as Pleurotropis benefica; intrinsically inferior competitor to Collyria; cocoons may be mistaken for unparasitized in field
More Details
Superparasitism dynamics
Mathematical analysis of C. calcitrator showed that observed distributions in deviate significantly from random oviposition expectations, indicating active host discrimination. However, host shortage at peak parasite activity can cause high rates, potentially misleading assessment of discrimination ability.
Sampling considerations
Estimates of rates from wheat stubble may underestimate true parasitism because larvae and their are removed with harvested straw, and because inferior competitor cocoons (Pediobius) must be accounted as unparasitized by Collyria.
Phenological matching
Development timing from termination of larval to varies by less than one day across C. catoptron and its C. fumipennis, and patterns are similar, facilitating successful .
Sources and further reading
- BugGuide
- GBIF taxonomy match
- iNaturalist taxon
- NCBI Taxonomy
- Catalogue of Life
- Hispanic collyria seals in the Roman empire
- REGULATION OF THE NUMBER OF AN ORDINARY STEM BREAD SAWER BY A SPECIALIZED PARASITE COLLYRIA COXATOR VILL.
- A mathematical analysis of superparasitism by Collyria calcitrator Grav
- Superparasitism by Collyria calcitrator, Grav
- Notes on the Distribution ofCephus Pygmaeus, Linn., and of its Parasite,Collyria calcitrator, Gray
- Status in Ontario of Collyria calcitrator (Grav.) (Hymenoptera: Ichneumonidae) and of Pediobius beneficus (Gahan) (Hymenoptera: Eulophidae) as Parasites of the European Wheat Stem Sawfly, Cephus pygmaeus (L.) (Hymenoptera: Cephidae)
- Preliminary evaluation of the parasitoid wasp,Collyria catoptron, as a potential biological control agent against the wheat stem sawfly,Cephus cinctus, in North America
- Assessing phenological synchrony between the Chinese sawfly, Cephus fumipennis (Hymenoptera: Cephidae), its egg-larval parasitoid, Collyria catoptron (Hymenoptera: Ichneumonidae), and the North American sawfly, Cephus cinctus: implications for biological control
- A New Species of Collyria Schiødte (Hymenoptera: Ichneumonidae: Collyriinae), a Parasitoid of Cephus Fumipennis (Hymenoptera: Cephidae) in China, and Potential Biological Control Agent for Cephus Cinctus in North America