Spilomyia

Meigen, 1803

Hornet Flies

Species Guides

11

Spilomyia is a of hoverflies (Syrphidae) notable for exceptional of , particularly yellowjackets. visit flowers to feed on nectar and pollen, contributing to pollination. Unlike many other syrphid flies, Spilomyia do not exhibit mating at blossoms. The genus contains approximately 40 described species distributed across the Holarctic region, with about 13 species in North America. Larvae develop in water-filled tree holes, feeding on decaying organic matter.

Spilomyia liturata by no rights reserved, uploaded by Steve Wells. Used under a CC0 license.Spilomyia liturata by (c) Charles Swift, some rights reserved (CC BY), uploaded by Charles Swift. Used under a CC-BY license.Spilomyia longicornis by (c) Nick Block, some rights reserved (CC BY), uploaded by Nick Block. Used under a CC-BY license.

Pronunciation

How to pronounce Spilomyia: //ˌspaɪl.oʊˈmaɪ.ə//

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

Identification

Distinguished from by single pair of wings (wasps have two pairs), though this requires close inspection. From other syrphid : wasp-mimicry more elaborate than most, including wing darkening and antennal modification. markings and leg-waving are distinctive. From actual yellowjackets (Vespula, Dolichovespula): eyes meet dorsally in flies but are separated in wasps; flies lack constricted wasp waist; structure differs (flies have aristate antennae, wasps have long, thick, non-aristate antennae).

Images

Habitat

associated with flowering vegetation where they visit blossoms. Larval : water-filled tree holes (phytotelmata) containing decaying organic matter. Occurs in wooded and semi-wooded environments where suitable larval microhabitats and adult floral resources coexist.

Distribution

Holarctic distribution. North America: approximately 13 . Europe: multiple species including S. diophthalma, S. saltuum. Asia: records from China, Japan, Pakistan (Swat Valley), Russia, and other regions. Specific species have more restricted ranges; S. longicornis documented in Illinois, USA.

Diet

feed on nectar and pollen obtained from blossoms. Larvae feed on decaying organic matter in water-filled tree holes.

Life Cycle

Complete . Larvae develop in water-filled tree holes, feeding on decaying organic matter. emerge and visit flowers for feeding. Specific details on -laying, , and developmental duration not documented in available sources.

Behavior

visit blossoms solely for feeding, not for mate-finding. Males do not patrol inflorescences or initiate copulation at flowers— absent in this that is present in many other syrphids. Some wave front legs to simulate . Wingbeat frequency in nearly identical to yellowjacket model species, contributing to both visual and auditory mimicry.

Ecological Role

function as through flower visitation. Larvae serve as decomposers and nutrient cyclers in tree hole microhabitats. of may reduce pressure, though specific interactions not documented.

Human Relevance

Potential in natural and agricultural systems. Mimicry may cause misidentification as stinging , leading to unnecessary concern. Historical specimen collections have been used in conservation assessments and range change studies, including identification of of potential conservation concern.

Similar Taxa

  • Vespula (yellowjackets)Primary mimicry model; distinguished by two pairs of wings, separated , constricted waist, and non-aristate
  • Dolichovespula (aerial yellowjackets)Another mimicry model; same distinguishing features as Vespula
  • Other Syrphidae (e.g., Mallota, Microdon, Toxomerus)Co-occurring hoverfly ; Spilomyia distinguished by more elaborate -mimicry including wing darkening, antennal modification, and leg-waving

Misconceptions

Frequently mistaken for yellowjacket due to convergent coloration, body shape, and sound. The ' Flies' reflects this mimicry but may perpetuate confusion with actual hornets (Vespa).

More Details

Mimicry sophistication

Spilomyia represents one of the most elaborate cases of in insects, combining visual (color, patterns, wing darkening, antennal simulation), behavioral (leg-waving), and auditory (wingbeat frequency) components.

Research significance

Specimens of S. longicornis in the Illinois Natural History Survey collection contributed to a 2023 study demonstrating the value of digitized museum collections for tracking range changes and identifying conservation priorities.

Sources and further reading