false milkweed bug

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not listed

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False milkweed bug is a medium-sized seed bug. It occurs in the United States east of the Great Plains, in Ontario Canada, and in Mexico.

Adults are ¼″ to ½″ (6.5 to 13 mm) long, fairly hard-bodied, robust, and oval.

The head is mostly black with a large. Y-shaped, orange mark extending from the top of the head (vertex) to in front of each compound eye. The beak-like part of the head containing the mouth parts (rostrum) has four segments. It is short, slender, and projects downward and forward when sucking plant juices. It is tucked into a groove on the underside of the thorax when not in use. The antennae are much longer than the head but much shorter than the body. They have four segments including the short basal segment (scape). They are not widened at the tip (clubbed). There are two large compound eyes on the sides of the head and two small simple eyes (ocelli) on the top of the head. The distance between an ocelli and the adjacent compound eye is about six times the distance between the two ocelli.

The exoskeletal plate covering the thorax (pronotum) is about twice as wide at the rear than at the front. The front third is mostly black. The rear two-thirds is mostly orange with two broad black spots at the rear margin and two small spots at the front.

There are two pairs of wings, and they are held flat over the body when at rest. The front wings (hemelytra) are longer than the hind wings and only slightly longer than the body. The exoskeletal plate between the wing bases (scutellum), is large, triangular and entirely black. The hemelytra have a thickened part at the base and a thin, membranous part at the tip, with a clear dividing line between the two. The thickened part is comprised of a narrow area (clavus) behind the scutellum when the wings are closed, and a broad marginal area (corium). The clavus is orange in front, black at the rear. The corium is mostly orange with a small black spot on the inner margin near the front and a large black spot on the outer margin near the middle. The combined black areas on the scutellum, clavus, and corium give the appearance of two overlapping heart-shaped spots in the middle and a large spot on each side. The membranous portion of the hemelytron has 4 or 5 veins. It is entirely black, without white spots and without a white margin.

The legs are black. The last part of the leg (tarsus), corresponding to the foot, has 3 segments. The last tarsal segment has a claw at the tip and a pad at the base of each claw.

Total length: ¼″ to ½″ (6.5 to 13 mm)

Large milkweed bug (Oncopeltus fasciatus) is larger. The pronotum is black with orange lateral margins. Each hemelytron has one forward-pointing and one backward-pointing orange triangle separated by a broad black band. The membranous portion of the hemelytra does not have white spots or edges.

Small milkweed bug (Lygaeus kalmii) has a single, large, black, heart-shaped triangle on the back. The red mark on the top of the head is an unbranched line.

Seeds of false sunflower (Heliopsis helianthoides)

Sources

24, 30, 82.

Common

Lygaeus turcicus false milkweed bug

Lygaeus turcicus, false milkweed bug, on asteraceae (formerly compositae) seedheads. Barnes Prairie, Racine Co., WI, photos were taken on November 9, 2021. These bugs added a bright note to a late autumn walk.

Location: Barnes Prairie, Racine Co., WI

Lygaeus turcicus, false milkweed bug, on Asteraceae (formerly Compositae) seedheads. Barnes Prairie, Racine Co., WI, photos were taken on November 9, 2021. These bugs added a bright note to a late autumn walk.

Location: Woodbury, Minnesota