Chrysotoxum perplexum explained

Chrysotoxum perplexum is a North American species of syrphid fly in the family Syrphidae.The adults are strong mimics of wasps.^[1] Larvae of this genera, when known, are aphid predators.^[2]

Description

For terminology seeSpeight key to genera and glossary

Length 122NaN2

Head:The face is convex with a prominent tubercule at the lower end of the facial stripe. The vertex and front are black, with the upper part of the front being whitish pollinose. The first joint of the antennae is longer than the second, and the third is slightly longer than the first and second combined. Lastly, the arista is reddish.

Thorax:The scutellum has a broad transverse black band, leaving a narrow yellow margin at the base and apex.

Abdomen:The sides of the first abdominal segment are yellow, and the arcuate bands on the other segments are narrowly interrupted. The arcuate bands on the second and third segments extend to the lateral margin, while the one on the fourth segment is narrowly separated. The posterior margin of the second segment is entirely black, while the yellow posterior marginal band on the third and fourth segments is narrow on the sides and expands in the middle, being widest on the fourth segment. The two elongated spots on the fifth segment are curved, and the central triangle is small, leaving a very broad V-shaped mark.

Wings: The wing vein R4+5 is clearly dipped into cell r4+5, and the costal margin of the wing is brown.

Legs:The base of the front and middle femora are dark brown.^[3]

Distribution

United States: Vermont, New Hampshire, New York, Pennsylvania, Maryland, Maine, Virginia, West Virginia.

Canada: Quebec, Nova Scotia, New Brunswick, Saskatchewan.^[4]

References

^[5]

Notes and References

1. Gilbert . Francis . 2004 . The evolution of imperfect mimicry in hoverflies. . Cambridge University Press . 1–42 .
2. Shannon . Raymond C . 1927 . The Chrysotoxine Syrphid-Flies . Proceedings of the U.S. National Museum . 69 . 1–20 .
3. Johnson . Charles Willison . 1924 . A review of the New England species of Chrysotoxum . Occasional Papers of the Boston Society of Natural History . 5 . 97–100 .
4. Web site: Chrysotoxum perplexum . GBIF . 2023-02-20.
5. Web site: Chrysotoxum perplexum Report. Integrated Taxonomic Information System. 2019-09-24.