Trimerotropis pallidipennis (Burmeister)


Adult female

Common name - Pallid-winged grasshopper (Helter, 1972).

Geographic distribution - British Columbia (Canada), Montana, Colorado and Texas, south to Mexico and South America (Brooks, 1958). Its Colorado range includes the plains of the northern part of the state and the mountain valleys to timberline (Hebard, 1929). The subspecies Trimerotropis pallidipennis saline occurs from Alberta, Saskatchewan and Manitoba (Canada) to Oklahoma and Colorado (Heifer, 1972). In Colorado it is found in the eastern areas while T. pallidipennis pallidipennis is found throughout the state (Alexander, 1941).

Colorado Distribution Map

Habitat - bare, waste areas of thin soil and sparse vegetation (Ball et al., 1942; Hebard, 1928). The subspecies T. pallidipennis saline is found in akaline areas (Alexander, 1941).

Food habits - feeds on cultivated crops especially vegetables, alfalfa, mile, barley, cotton and corn. It also eats cheatgrass brome, Sisymbrium altissimum, bluebunch wheatgrass, timothy and Plantago purshii (Ball et al., 1942; Banfill and Brusven, 1973; Hewitt, 1977).

Eggs - eggs are pale yellow, 18 per pod. Average egg length, 5 mm; average diameter, 1 mm. Pods are delicate with a thin layer of froth over the eggs (Ball et al., 1942; Onsagerand Mulkern, 1963).

Nymph - five or six instars (Ramsey, 1964).

Adult - medium to large size, slender. General color is grey marked with brown. Face is vertical, vertex is rounded, antennae are slender. Dorsal posterior edge of pronotum is a right angle. Median carina of pronotum is cut by two sulci. Bands on tegmina are irregular, consisting of dark blotches. Wings are pale yellow with a narrow, black band beyond the middle and a short spur reaching over half the distance to the wing attachment. Apex is clear. Hind femora have two bands and a black knee on the inner face. Hind tibiae are yellow. Male length, 32 mm; female, 44 mm (Ball et al., 1942). The subspecies, T. pallidipennis saline usually is more reddish without strong bands on the tegmina, and wing band is weak. The wing band is in the middle of the wing, and the spur reaches less than half the distance to the wing attachment (Heifer, 1972).
 
Pronotum (Side view) Pronotum (Possible)
Wing Tegmen

Oviposition - eggs are deposited in soil (Barnes, 1960).

Seasonal history - eggs overwinter. Adults may be found from early June to late October. Adults migrate in June and July (Ball et al., 1942; Scoggan and Brusven, 1972).

Abundance and importance - very common on the Great Plains and westward and from Canada to Mexico. It can cause injury to crops in migration and can be annoying because it is attracted to lights at night (Ball et al., 1942; Scoggan and Brusven. 1972).

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Biology of Common Colorado Grasshoppers
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