two-spotted grass bug

not listed

not listed

not listed

Two-spotted grass bug is a soft-bodied, colorful, plant bug. It is small for a true bug (suborder Heteroptera) but fairly large for a plant bug (family Miridae). It is native to Europe and was introduced into North America, where it is now widespread. It is uncommon in Minnesota. It is considered a minor agricultural pest, attacking several cereal crops, especially wheat.

The head is shorter than the first segment of the thorax (prothorax) and much shorter than the antennae. It is black in front and at the back, yellow or yellowish-green at the top. The light area at the top usually extends to the edges of the compound eyes and often extends in a narrow strip to the back of the head. There are two large compound eyes and no simple eyes (ocelli). The mouth parts take the form of a long, 4-segmented beak that projects downward and is optimized for piercing and sucking. The antennae are long and yellow tinged with black.

The body is soft, ¼″ to 5 ⁄16″ long, elongated, and more or less parallel along the sides.

The upper thoracic shield (pronotum) yellow at the sides and yellow or greenish-yellow on top. It has two large, elongated, oval spots that extend from near the front (anterior) margin to the rear (posterior) margin.

There are two pairs of wings. They are held flat over the body when at rest. They are longer than and completely cover the body. The front wings (hemelytra) are longer than the hind wings. The front wings (hemelytra) are longer than the hind wings. The exoskeletal plate between the wing bases (scutellum) is large, triangular, bright yellow or greenish-yellow with no black markings. The hemelytra have a thickened, leathery 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 the narrow area (clavus) behind the scutellum when the wings are closed and the broad marginal area (corium). At the end of the corium there is a small but distinct triangular area (cuneus). Each hemelytron has three oblique streaks, two black and the third blackish. The lower (distal) black streak extends toward the inner margin of the cuneus. As the insect ages, the black marks become darker and larger, merging into a single large black spot. The cuneus) is always yellow with no black markings. The membranous tip is black or blackish-brown with yellow veins. It has two closed cells. The hind wing is completely thin and membranous.

The legs are long and delicate. The third (femur) and fourth (tibia) segment of each leg is yellow. The end part that corresponds to the foot (tarsus) is black and has three segments.

The female is similar to the male but is greenish-yellow and has and the black markings are paler and much less extensive.

Total length: ¼″ to 5 ⁄16″

Fields, meadows

Mid-June to mid-August

Inflorescence of various grasses, especially timothy

Inflorescence of various grasses, especially timothy

Sources

24, 27, 29, 30, 82.

Widespread in North America. Not common in Minnesota.

It was on my dahlia bloom

Location: St. Michael, MN

It was on my dahlia bloom

Location: Woodbury, MN

Location: Woodbury, MN