Montana Field Guide

The following is taken from Brooks (1958), Vickery and Kevan (1985), Pfadt (2002), Capinera et al. (2004), and Scott (2010). This large, robust species is so named for the two pale yellow stripes extending from the back of the eyes, across the lateral lobes of the pronotum, to the tips of the forewings. They converge to form a V-shape. On the head and pronotum, the stripes are usually bordered below with black. The wing (tegmina) length of males reach or slightly surpass the knee of the femur. Female wings are slightly shorter.

Eggs begin to hatch in mid-spring over a 4 to 6-week period. It is an early-hatching species. Nymphs pass through 5 to 6 instars. Adults occur from late June to September or October, when they are eventually killed by frost (Capinera and Sechrist 1982, Pfadt 2002, and Scott 2010).

The following is taken from Brooks (1958), Vickery and Kevan (1985), Pfadt (2002), Capinera et al. (2004), and Scott (2010). Body length for males is 23 to >28 mm, females 29 to 45 mm. Color is variable from tan, brownish or greenish. Outer surface of the hind femur has a dark stripe on its upper half and yellow on the lower. The hind tibia can be bluish green, blue, or poppy red with black spines.

Among the Melanoplus, it is easy to identify. The Two-striped Grasshopper is one of two of the largest species in the genus. The other is the Differential Grasshopper (M. differentialis).

This species is highly adaptable and occupies many habitat types. It prefers habitats with lush vegetation, but is also associated with disturbed sites along roadsides, field borders, gardens, and agricultural sites (Vickery and Kevan 1985, Pfadt 2002, Capinera et al. 2004, and Schell et al. 2005).

The Two-striped Grasshopper is polyphagous, feeding on a vast diversity of grasses, forbs, trees, shrubs, and many cultivated plants. It seems to prefer, and need, forbs because it seems to do physically poor in their absence. The host food plants include several families, such as mustards, fixweed, pepperweed, plantain, alfalfa, red clover, sunflowers, prickly lettuce, sow thistle and many more composites of the Asteracae (Pfadt 2002, Capinera and Sechrist 1982, Capinera et al. 2004, and Schell et al. 2005).

Grasshoppers that have moved into crops return to field borders and roadsides for reproduction, where the soils are hard and compacted. Irrigated fields of alfalfa are also attractive oviposition sites, as are south-facing ditch banks. Egg laying occurs from mid-August to mid-October, depending upon frost occurrences. Females select crowns of grass or roots of weeds for egg laying. They generally deposit 1 to 2 pods, containing 43 to 135 eggs arranged in columns of four per pod (Capinera and Sechrist 1982, and Pfadt 2002).

The following is taken from Pfadt (2002) and Schell et al. (2005). The Two-striped Grasshopper is known for its periodic outbreaks and a major crop pest of alfalfa, small grains and corn. During outbreaks, it may completely destroy crops. It is also a common pest defoliator of garden plants, vegetables, trees and shrubs in suburban areas.

It is believed that this species became a serious pest when early settler agricultural development unknowingly sowed various weed seeds with their crops. These, now, invasive species grew along crop borders, roadsides, and irrigation ditch banks, creating ideal habitats for egg laying sites, especially along south-facing ditch banks and compact soils at field margins.