Strongygaster triangulifera

(Loew, 1863)

bristle fly

Strongygaster triangulifera is a small parasitic tachinid fly widely distributed across North America. It is a that primarily attacks Coleoptera, with documented in at least 10 including Coccinellidae, Chrysomelidae, Curculionidae, and Scarabaeidae. Records also exist from Dermaptera, Hemiptera, Lepidoptera, and Orthoptera. The has been observed parasitizing both native and insect species, including the multicolored Asian lady beetle (Harmonia axyridis) and the kudzu bug (Megacopta cribraria).

Strongygaster triangulifera by (c) Even Dankowicz, some rights reserved (CC BY), uploaded by Even Dankowicz. Used under a CC-BY license.

Strongygaster triangulifera by (c) Cole Shoemaker, some rights reserved (CC BY), uploaded by Cole Shoemaker. Used under a CC-BY license.

Pronunciation

How to pronounce Strongygaster triangulifera: /strɒnˌdʒaɪˈɡæstər traɪˌæŋɡjuˈlɪfərə/

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

Identification

Small tachinid fly; specific diagnostic features for field identification not documented in available sources. As a member of Strongygastrini, likely exhibits characteristics of the tribe including particular bristle patterns, but -level identification keys are not provided in cited literature.

Images

Distribution

North America: Canada, United States, Mexico. Also recorded from South America: Argentina, Chile. Within North America, documented from both eastern and western regions including Oregon, Ontario, North Carolina, Virginia, and Alabama.

Host Associations

Coccinella trifasciata perplexa - low parasitization levels (<1%) in Ontario
Coleomegilla maculata lengi - low parasitization levels (<1%) in Ontario
Harmonia axyridis - fluctuating levels 3.0-31.1% in 1993, 0-6.5% in 1994 in North Carolina and Virginia; first western North America record from Oregon
Chauliognathus pennsylvanicus - first record for Cantharidae and first tachinid record for this
Megacopta cribraria - in Alabama
Coleoptera (general) - most frequently reported order; includes Alleculidae, Bruchidae, Chrysomelidae, Cleridae, Coccinellidae, Curculionidae, Lampyridae, Meloidae, Nitidulidae, Scarabaeidae
Dermaptera - scattered reports
Hemiptera - scattered reports
Lepidoptera - scattered reports
Orthoptera - scattered reports

Behavior

that attacks adult stages of insects. Parasitization levels vary considerably by host and location, ranging from less than 1% in some native coccinellids to over 30% in some of Harmonia axyridis.

Ecological Role

agent; that contributes to of pests and other insects. Has been documented attacking including Harmonia axyridis and Megacopta cribraria, suggesting potential role in natural suppression of established pests.

Human Relevance

Potential biocontrol significance due to of agricultural and nuisance pests, particularly the kudzu bug (Megacopta cribraria) and multicolored Asian lady beetle (Harmonia axyridis). No direct economic impact or medical significance documented.

Similar Taxa

Other Strongygaster speciescongeneric may share similar ranges and require detailed morphological examination for separation
Other Phasiinae tachinids members often exhibit lifestyles on beetles and other insects; identification to / requires knowledge

More Details

Taxonomic history

Originally described as Hyalomyia triangulifer by Loew in 1863; later transferred to Strongygaster. Has also been placed in synonymy with Hyalomyodes by some authors.

Parasitization variability

Documented parasitization rates show substantial temporal and spatial variation. In Harmonia axyridis, rates dropped from 3.0-31.1% in 1993 to 0-6.5% in 1994 in the same region, suggesting -dependent or environmentally mediated fluctuations.