Phlibostroma quadrimaculatum (Thomas)

 
Adult male Adult female

Common name - "P-quad" grasshopper or Four-spotted grasshopper (Hantsbarger, 1979; Helter, 1972).

Geographic distribution - the Great Plains from Alberta, Saskatchewan and Manitoba (Canada) to Mexico. Also in Arizona (Otte,1981). Its range in Colorado is from the eastern grasslands to the eastern mountain valleys (Hebard, 1929).

Colorado Distribution Map

Habitat - dry, mixed prairie (Brooks, 1958).

Food habits - feeds on grama and buffalo grasses, but especially blue grama. It also has been observed feeding on sunsedge, textile onion, sand dropseed, fringed sage and scarlet globemallow (Bruner,1897; Kumar et al.,1976; Mulkern et al., 1969).

Eggs - six tan eggs are deposited in two columns within a pod. Average egg length, 4.8 mm; average width, 1.3 mm (Onsager and Mulkern, 1963).

Nymph - four instars (Ramsey, 1964)

Adult - small to medium size and robust. General color is brownish-green. Face is nearly vertical. Vertex and back of head are strongly curved. Head is unusually large. Antennae are thread-like. Lateral carinae are light colored and distinctly constricted near middle. Dorsal posterior margin of pronotum is a rounded right angle. Tegmina have four distinct crenulate markings. Wings are colorless. Posterior femora are banded on upper and outer faces. Posterior tibiae are red-orange to tan. An active grasshopper. Male length, 12 mm; female, 18 mm (Ball et al., 1942; Hantsbarger, 1979; McNeill, 1896).
 
Head (Side view) Pronotum (Top view)
Tegmen Tegmen (Possible)

Seasonal history - adults can be found from July through September or October (Ball et al., 1942).

Abundance and importance - common and destructive to pastures and rangelands (Hantsbarger. 1979).

P. quadrimaculatum fact sheet from the Field Guide to Common Western Grasshoppers
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