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The Russianthistle grasshopper is a medium-sized robust species. It has a distinctive color pattern of shades of tan with fuscous markings (Figs. 6 and 7). The wings of the northern subspecies, A. t. turnbulli, may be 2 to 4 mm short of the end of the abdomen (and also the end of the hind femur, a less variable measurement). The wings of the southern subspecies, A. t. bruneri, are longer, surpassing the end of the abdomen (Fig. 8). Lateral light bands mark the sides of the pronotal disk and are separated by a broad fuscous band. The latter band is divided by the median carina, which may be colored partly or entirely light tan. The hind femur has three characteristic fuscous marks on the medial area. These dark marks usually extend dorsally onto the upper marginal areas. The hind tibia is usually medium blue with a pale tan annulus near the base. The male possesses tiny furcula represented by minute lobes, a subgenital plate with a conspicuous subapical tubercle, and triangular slender cerci (Fig. 9).
The nymphs (Fig. 1-5) are identifiable by their structure, color patterns, and shape. 1. Head with face nearly vertical, head tan to pale tan or green with several to many fuscous spots; compound eye with large pale tan spots in brown reticulum; antennae filiform, first two segments (scape and pedicel) pale yellow with several brown spots, rest of segments (flagellum) fuscous, each with pale anterior annulus. 2. Pronotum tan or green with several to many brown spots, median carina pale contrasting with main color of disk, the pale line extends onto abdomen; disk becomes distinctly wider posteriorly (a diagnostic character). 3. Outer medial area of hind femur uniformly tan or green with several to many brown spots or with three fuscous markings, tan, and spotted (Fig. 2). 4. Hind tibia is green, blue or pale gray, usually with brown spots. 5. General body color tan or green. Characters especially useful in identifying the nymphs are: 1. the shape of the pronotal disk, which widens from front to rear, 2. most individuals heavily spotted brown or fuscous, 3. nymphs are colored pale green, pale tan, or pale gray, 4. in tan or gray nymphs, three characteristically shaped dark markings are usually present on the medial and marginal areas of the hind femur (Fig. 1 and 2), in green forms, these markings are faint or lacking (Fig. 3). |
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