About Meromacrus acutus (Fabricius, 1805)
For terminology, refer to Speight’s key to genera and glossary of external images. This species has a body length ranging from 13–18 mm (0.5–0.7 in). On the head, the frons has a broad black stripe, with yellow pile on the sides below the ocelli. The face is yellowish red, densely covered on the sides with whitish pollen and bright yellow pile. It is marked by a broad median stripe and shining black cheeks; the broad black facial stripe may sometimes be reddish. The antennae are reddish brown, located on a raised antennifer, and have an orange arista. The posterior orbits have abundant short yellow pile, with a patch of black at the ocellar triangle. The thorax is shining black with distinct golden yellow markings. Two black stripes with short black pile extend from the front of the scutum to near the lateral sutures. Paired bright yellow oval markings sit next to the humerus. A transverse yellow line runs along the lateral suture, extending to the midlegs. An irregular yellow line runs in front of the scutellum, extending laterally to under the postalar callus. The scutellum is brown, with yellowish coloring along its posterior border. The pleurae are black, with a yellow spot. Light yellow spots are located at the anterior spiracles and just below the humeri, and a posterior pair of white spots sits on the sides of the metanotum. The abdomen is patterned black and yellow. The first segment is black, with paired oval spots of yellow pile on its hind section. The second segment is black, narrow, and has a posterior yellow margin. The third segment has a yellow pilose spot on each side at the front, and a quite narrow yellow hind margin. The fourth segment is similar to the third, but its spots are smaller, and its hind margin is very narrow or entirely absent. The male genitalia of this species were described by Nayar. The wings are yellowish at their base, with the front edge a dark smoky black that fills the sub-costal, marginal, submarginal, outer part of the first basal, and anterior part of the first posterior cells. Distinctive venation includes a present spurious vein (sv), R4+5 looping into r4+5, and a closed cell r2+3. The legs are light reddish yellow, except the hind femora which are mostly black.
