|Melanoplus angustipennis |
common name Narrowwinged sand grasshopper
The narrowwinged sand grasshopper can be found in prairies with sandy soil, vegetated sand dunes, blowouts, and the banks of streams and lakes. It is abundant in disturbed areas like roadsides, crop edges, and weedy fields (Pfadt 2002). It has been collected in central and southern Alberta.
Nymphs (no wings or short wing buds) hatch from egg pods in the soil during the first two weeks of May. Adults (wings extend the length of the abdomen) can be found from July to October (Pfadt 2002).
The Melanoplusangustipennis is a medium-sized spurthroated grasshopper with variable colouration. This and other grasshoppers of the subfamily Melanoplinae often have a spiny bump on their "throat" between their front legs (Johnson 2002). It can range from dull gray to bright yellow or tan and may have red or blue hind tibia. The wings of this species extend the length of the abdomen or up to 4 mm beyond. The males of this species can be identified by the shape of their spatulate cerci and the abrupt narrowing of their supraanal plate (the cup-shaped plate at the end of the male abdomen). Females can be identified by using size, markers and colouring to associate them with the males (Pfadt 2002).
The life cycle of this species is described in Pfadt's Field Guide to Common Western Grasshoppers (2002). Both male and female nymphs mature through 5 instars before moulting into the adult morph. This usually takes 36-42 days. Male adults fledge about one week before the females and the female adults reach sexual maturity about two weeks after fledging. In this species, the males and females are about the same size, and mating pairs can be seen near the end of July. After mating, females will deposit 2-3 egg pods in sandy soil near vegetation. The pods are curved tubes about 1.5 cm long containing 12-18 eggs. Nymphs hatch the following spring.
This species is of occasional concern to ranchers and farmers. It has been a dominant species in outbreaks that consist of species assemblages (Pfadt 2002).
Nymphs and adults of this species enjoy a wide range of prairie forbs, grasses, shrubs, moss, fungi, and even dead insects. The majority of their diet, about 62%, consists of rangeland forbs including western ragweed, prairie sunflower, western sticktight, and cud-weed sagewort. When forbs are unavailable, the grasshoppers will eat prairie grasses, about 21% of their diet, including blue grama, needleandthread, sand dropseed, and western wheatgrass (Pfadt 2002).
This species ranges across North America from the western edge of the Great Plains to mid-way through the Great Lakes in the East. They are found as far north as central Alberta and as far south as the southern States (based on range map in Pfadt 2002) which agree with the Strickland Museum's records.
No migratory swarms have been observed in this species, but dispersal is evident. Adults have been found up to 21 km away from the habitat of a known population (Pfadt 2002).
These grasshoppers shelter for the night under canopies of ground litter, or if on disturbed land they may climb up a tall plant and spend the night with their head towards the sky (Pfadt 2002).
Early in the morning they emerge from their shelters and sit on the ground waiting for the sun to warm them. They bask in the sun by turning sideways and lowering the hind leg on the sunny side. When warm enough, the grasshoppers begin to walk in search of food and mates. They jump if disturbed and can fly 0.5-2.5 m at 10-25 cm off the ground. Their evasive flight is silent and usually straight (Pfadt 2002).
|species page author||Bird, H.||2010 |