eastern calligrapher

Sryphid flies are considered beneficial because they prey on insects that attack ornamental plants and crops. Eastern calligrapher is a common small syrphid fly. It occurs in North America east of the Great Plains and in adjacent Canadian provinces. It is one of the most abundant species of hover flies (Family Syrphidae), also called flower flies. It is very common in Minnesota.

Adults are ¼″ to 5 ⁄16″ (6.1 to 7.6 mm) in length. The coloration is an example of Batesian mimicry, resembling the warning coloration of stinging bees and wasps.

The back of the head is white. There are two large compound eyes, one on each side of the head, and three small simple eyes (ocelli) in a triangle at the top of the head between the compound eyes. The compound eyes are reddish-brown and are narrowly indented on the rear margin in the shape of a broad triangle. On the male the compound eyes meet near the top of the face. On the female they do not. On the male the face is white. On the female there is a dark, broad, vertical stripe on the white face extending from between the eyes to the antennae. The antennae are short and yellow.

The large, middle section of the thorax (mesonotum) is covered by a shield-shaped exoskeletal plate. The large, forward portion of the shield (scutum) is blackish-brown with faint, yellowish-brown, longitudinal stripes. It is hairless. On most Toxomerus species there is a very small yellow spot, called the supracoxal marking, on the side of the thorax just above the first segment (coxa) of the front leg. Supracoxal means “above the coxa”. This mark is present on all Toxomerus species except T. germinatus and T. boscii. Thin-lined calligrapher (T. boscii) does not occur in Minnesota. The smaller, rearward part of the shield (scutellum) is similarly colored but has yellow hairs. The shield has a well-defined yellow margin.

The abdomen is yellow with black stripes. The rear half of the third abdominal segment is mostly black. The tip of the abdomen is rounded in males, pointed in females.

On males, the third segment (femur) of the hind leg is bowed (arcuate).

The wings are clear.

Total length: ¼″ to 5 ⁄16″ (6.1 to 7.6 mm)

A wide variety of habits, including forests, fields, savannas, marshes, bogs, and fens

Late April to late October

Adults can often be seen hovering over plants, a favorite activity that gives this family one of it’s common names.

Syrphid flies do not bite or sting.

Aphids and mites

Flower pollen and nectar

Sources

7, 24, 27, 29, 30, 82, 83.

Telford, Horace S.. (1939). The Syrphidae of Minnesota. University of Minnesota. Minnesota Agricultural Experiment Station.

Very common

Tribe
The subfamily Syrphinae was traditionally divided into four tribes, Bacchini, Paragini, Syrphini and Toxomerini. The genus Toxomerus was placed in the tribe Toxomerini, and it was the only genus in that tribe. Several molecular studies between 2008 and 2016 showed that including the tribes Paragini and Toxomerini made the tribe Syrphini include only organisms from a common ancestor or ancestral group, but not all of the descendants of that ancestor or group – it was paraphyletic, and therefore invalid. A recent phylogenetic and evolutionary analysis of the subfamily Syrphinae (Mengual et al., 2022) showed that the family comprised just three major lineages of tribal rank, Melanostomini, Bacchini and Syrphini, and that Syrphini contained the former tribes Paragini and Toxomerini.

Toxomerus geminatus
Andree Reno Sanborn

Flower Fly (Syrphidae:Toxomerus geminatus) Wasp Mimic
Carl Barrentine

Syrphid Fly (Syrphidae: Toxomerus geminatus) on Leaf
Carl Barrentine

Location: Lake Shore, MN

Location: Barnes Prairie, Racine Co., WI

Location: Woodbury, MN