bee-mimic robber flies

Laphria canis complex is an artificial grouping of at least six closely related species of small to medium-sized bee-mimic robber flies. One species occurs only in the far west. Two species are undescribed. The remaining three species have been collected in Minnesota (University of Minnesota Entomology Collection). The western species is also in that collection, but it is so far out of its known range that the identification must be questioned. Males of the species can be differentiated by the size of the genital bulb or by close examination of the genitalia. Females cannot be differentiated from a photograph.

Laphria canis complex occurs in the United States and southern Canada east of the Great Plains. In Minnesota it is most common in the southeast quarter of the state, where it is at the western extent of its range. It is found from June through August in shaded woodlands, woodland openings and edges, and fields near woodlands. Adults perch on the leaves of low plants. Larvae live in soil or rotting wood, where they prey on the larvae of other insects.

Adults are black, slender, and small, usually ¼″ to ½″ (7 to 12 mm) in length but sometimes up to ⅝″ (16 mm) long. The thorax and abdomen are thinly covered with pale grayish hairs.

There are two large compound eyes on the side of the head and three small simple eyes (ocelli) in a triangle on top of the head. The top of the head is depressed (“hollowed out”) between the compound eyes. The ocelli are on a prominent rounded projection (tubercle) in the middle of the head between the compound eyes. There is a prominent mustache of long, stiff, black bristles (mystax) on the immediately above the mouth. The hairs on the sides of the head and below the mouth (beard) are silvery. The antennae have 3 segments. The third segment is elongated.

The thorax is black. Depending on the angle of the light it may appear slightly golden. The small, knob-like structures on each side of the thorax (halteres) are yellow.

The abdomen is long, slender, tapered, and black. The genital bulb at the tip of the abdomen is black. On Laphria canis it is much larger than the adjacent abdominal segment.

The wings are clear. They are pale at the base, moderately to barely smoky brown beyond.

The legs are stout and black. They are covered with long gray and black hairs. The last part of the leg (tarsus), corresponding to the foot, has five segments. The last segment has 2 pads.

Total length: ¼″ to ⅝″ (7 to 16 mm)

Shaded woodlands, woodland openings and edges, and fields near woodlands

Late May through August

Insect larvae

Small invertebrates

Sources

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

Robber Fly (Asilidae: Laphria canis) Anterior View
Carl Barrentine

Alfredo Colon
6/10/2024

Location: Albany, NY

Location: Barnes Prairie hedgerow, Racine Co., WI

The attached photo, taken on June 28, 2021 at Barnes Prairie hedgerow, Racine Co., WI is of a Laphria canis complex, bee-mimic robberfly, on a Solomon's seal leaf.

Location: Woodbury, MN

Location: Woodbury, MN

Location: Woodbury, MN