Compsilura concinnata

(Meigen, 1824)

European Tachinid Fly

Compsilura concinnata is a tachinid fly native to Europe that was introduced to North America in 1906 as a agent for the spongy moth (Lymantria dispar). It is an endoparasitoid of insect larvae, developing within the and eventually killing it. The attacks over 200 host species across Coleoptera, Lepidoptera, and Hymenoptera, but has proven ineffective against its intended target while causing significant non-target impacts on native Lepidoptera, including giant silk moths and .

Compsilura concinnata 1 by Gerson Tavares. Used under a CC BY 2.0 license.

Bulletin of the U.S. Department of Agriculture (1915) (20500292795) by United States. Dept. of Agriculture. Used under a No restrictions license.

Compsilura concinnata (10.3897-zookeys.934.50823) Figure 1 by Scaramozzino PL, Di Giovanni F, Loni A, Gisondi S, Lucchi A, Cerretti P (2020) Tachinid (Diptera, Tachinidae) parasitoids of Lobesia botrana (Denis & Schiffermüller, 1775) (Lepidoptera, Tortricidae) and other moths. ZooKeys 934: 111-140. https://doi.org/10.3897/zookeys.934.50823. Used under a CC BY 4.0 license.

Pronunciation

How to pronounce Compsilura concinnata: /kɔmpˈsɪljʊrə kɒnˈsɪnətə/

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

Identification

can be distinguished from similar tachinid flies by the combination of white , four black thoracic stripes, and house fly-like size and shape. Larval identification requires examination of mouth hook coloration (black) and anal hook number (three). The is most reliably identified through rearing from larvae or dissection of parasitized hosts.

Images

Habitat

Forest , agricultural fields, and suburban areas where larvae occur. In forest systems, show microhabitat preferences for attacking hosts near the ground, especially on leaves. Activity is primarily , with occurring mainly between 6:00 AM and 6:00 PM.

Distribution

Native to Europe; introduced to North America in 1906 and now established throughout the northeastern United States and adjacent Canada. Present in Denmark, Norway, Sweden, Portugal (including Madeira), and northern Tunisia. First recorded in Texas in 2018.

Seasonality

Multivoltine with 3-4 per year in temperate regions. lifespan ranges from 5-22 days. Larvae typically overwinter within larvae; because the intended target host Lymantria dispar overwinters as , the fly must parasitize alternative hosts for winter survival.

Host Associations

Lymantria dispar - Intended target ; rates typically below 5% during , increasing as decline
Hyalophora cecropia - Native non-target ; historically high rates (81% in 1990s), reduced in recent studies
Callosamia promethea - Native non-target ; historically high rates (68% in 1990s), reduced in recent studies
Danaus plexippus - Native non-target ; 9.8% overall rate observed in citizen science study, reaching 17% in fifth-instar larvae
Actias luna - Native non-target ; implicated in declines
Automeris io - Native non-target ; implicated in declines
Hemileuca maia - Native non-target
Euproctis chrysorrhoea - target
Trichoplusia ni - Agricultural pest
Pieris rapae - ; occurs mainly in autumn
Mythimna separata - used in laboratory studies
Orgyia trigotephras - First recorded in Tunisia
Charaxes jasius - Recorded in Iberian Peninsula
Spodoptera litura - Laboratory ; higher rate and host mortality than Pieris rapae

Life Cycle

. Females produce approximately 100 larvae and deposit them directly into larvae using a sickle-shaped ovipositor, usually one larva per attack. After injection, larvae migrate to the host and develop between the and gut wall, undergoing three instars over 10-17 days. Larvae typically kill hosts in approximately 10 days. Upon host , larvae emerge and pupate in soil or on substrate within a reddish-brown . Development from to occurs at 15.0-27.5°C; at 30°C pupariation occurs but adult fails. Lower developmental threshold is 7.7°C for females and 8.7°C for males.

Behavior

Females attach to backs using anal hooks, puncture the with an abdominal piercing structure, and inject larvae into the or body cavity. Multiple attacks on the same host may occur. Females often deposit no during oviposition attempts regardless of host movement, indicating imperfect oviposition is not caused by host defense. show heightened activity when first encountering preferred hosts such as Lymantria dispar, with preference for this host maintained regardless of prior conditioning experience. larvae avoid host immune response by hiding in specific tissues rather than using venom or viral countermeasures.

Ecological Role

functioning as a natural enemy of Lepidopteran larvae. In North America, has become a significant mortality factor for native non-target Lepidoptera, particularly giant silk moths (Saturniidae), contributing to declines and local extirpations in New England. The illustrates the risks of agent introduction when specificity is broad.

Human Relevance

Introduced to North America in 1906 for of Lymantria dispar; proven largely ineffective against this target due to low rates during and phenological mismatch (fly is multivoltine, is with ). Has caused substantial unintended ecological harm through parasitism of native Lepidoptera including economically and culturally significant such as and giant silk moths. Continues to be studied for its complex tritrophic interactions involving plant chemistry, quality, and .

Similar Taxa

Lespesia archippivoraBoth are tachinid of Lepidoptera; L. archippivora is more abundant on (75% of tachinid specimens vs. 10% for C. concinnata) and may represent a with specialized
Epicampocera succinctaBoth parasitize Pieris ; E. succincta is a restricted to mountainous areas with continuous , while C. concinnata is a found in all areas with seasonal activity mainly in autumn