Montana Field Guide

The following is taken from Hebard (1928), Otte (1984), Vickery and Kevan (1985), and Scott (2010). The general body color is dark grayish brown and can sometimes be reddish. Specimens in higher elevations tend to be darker than those in the lowlands. The median carina of the pronotum (thorax) is obvious and bluntly bilobed, with the anterior lobe being higher and longer. The tegmina (forewings) is dark banded, separated by light bands. The hind wing disk is sulfur yellow, sometimes with a pale greenish tinge and the black crossband is broad across the mid-region, narrowing toward the anterior edge, with a short, thick spur. The outer face of the hind femur is brownish. The inner face is pale to buff with a black median area, apical black ring, and knee. The hind tibia is yellowish to buff tinged with brown, and always with a lighter grayish ring at its base.

Communicative behavior/Crepitation*
Little has been reported in the literature, however Otte (1984), describes the following for this species, based only on California observations: “As males approach females, they produce widely and irregularly spaced pulses of stridulation*, using single strokes of the hind femora. These are interspersed with bursts of femur-shaking, one leg at a time.”

*Crepitation is the sound produced by grasshoppers making a clicking or snapping noise with their wings when in flight, during courtship, territorial encounters or being disturbed.

*Stridulation is rubbing one body part against another, usually the hind femur against the forewing in the case of the Band-winged Grasshoppers. This is often used for attracting a female during courtship (Otte 1970).

This species overwinters in the egg stage. Nymph hatching dates are unknown. Adults are present from July to October (Otte 1984, Vickery and Kevan 1985, and Scott 2010).

The following comes from Hebard (1928), Otte (1984), Vickery and Kevan (1985), and Scott (2010). The body length to tip of forewings for males is 25-35 mm, and 30-45 mm for females.

The Geyser Grasshopper is easily confused and difficult to identify from the Pallid-winged Grasshopper (Trimerotropis pallidipennis). Currently, in Montana, identification can be relatively certain by geographic range. Pallid-winged Grasshopper (T. pallidipennis) has been reported for only 3 southwestern counties (and possibly concentrated in that area), whereas T. diversellus is more widespread (compare range maps). Habitat type is also an indicator to note. Taxonomic morphological differences relative to the dorsal crest shapes of both species are well illustrated in Otte (1984). He also notes that the forewing (FW) and hind femur (HF) lengths for T. diversellus is shorter (measuring 1.85 mm FW/2.09 mm HF) than that of T. pallidipennis (2.08 mm FW/2.35 mm HF).

This species inhabits grasslands, alkaline depressions, and open pine woodlands up to about 7,500 feet (Otte 1984).

Unknown.

Unknown.