Hatching begins when the soil temperature has been 15-16 degrees C for about 200 hours. These nymphs resemble the adults but have wing pads instead of wings and, therefore, cannot fly. There are usually 5 or 6 nymphal instars. Grasshopper nymphs mature in 35-55 days. The adults may live for 4-6 weeks after mating and egg laying.
Many agronomists use 'foot-square' counts to rate their fields.
This is simply the number of grasshopper nymphs that jump from a square-foot area as you walk towards it. To do a field survey, start at one corner of the field, walk diagonally past the centre of the field, then turn and walk straight out to one side of the field. Make at least 20 of these square-foot counts in a survey. Control Tips Cultivation of fields in the fall may help control grasshoppers by exposing some of their eggs to predation, sun, wind, and frost. Deep tilling buries the eggs so deep that, upon hatching, the nymphs cannot reach the surface.