a. Adult female with ovipositor thrust into ground; b, egg in soil; c,nearly mature female nymphs; d, young nymph; e, nearly mature male nymphs. (All about natural size)
Mormon crickets, a wingless form of grasshopper, are bad pests in the Western States. Their range extends from the Missouri River west to the Cascade and Sierra Nevada Mountains and from the Canadian line south to northern California, Nevada, Utah, and Colorado. Most of the crops grown there are susceptible, but the greatest damage has been done to range grasses as well as to dry-land wheat and alfalfa.
The eggs are laid during the late summer and fall in well-drained, light sandy-loam soil. They are inserted just under the soil surface in bare spots between clumps of grass or sagebrush. Unlike grasshopper eggs, which are in a pod, cricket eggs are laid singly. Each female lays about 150 eggs. The young crickets start hatching early in April and reach maturity about 6 to 8 weeks later. There is one generation a year.
Mormon crickets persist in small numbers year after year in rough foothill and mountainous country remote from farm lands. When weather conditions over a period of years are favorable for maximum reproduction, their numbers increase rapidly and they start migrating. One to3 years usually elapse after migrations start before croplands are invaded.
Control: Mormon crickets can be easily killed in all stages by application of wet bait made according to either of the following formulas: (1) Standard wheat bran (no shorts or middling), 100 pounds; sodium fluosilicate, 4 pounds; water, 12 to 15 gallons. (2) Mill-run bran, 25 pounds; sawdust, 3 1/2 bushels; sodium fluosilicate, 4 pounds; water, 8 to 10 gallons.
Mix the dry ingredients thoroughly, add the water slowly, and continue mixing until a moist crumbly mash is attained. The bait should be spread at about 20 pounds an acre in the forenoon while crickets are migrating. It should be broadcast at right angles to the direction of migrations.
The following dry-bait formula is well adapted to spreading by aircraft: Standard bran (no shorts or middlings), 100 pounds; toxaphene, 1 pound, or chlordane, one-half pound; fuel oil or kerosene, one-half gallon.
Dissolve toxicant in oil and spray onto bran while mixing. This bait can be applied at any time of day at the rate of 10 pounds per acre. It is not recommended for spreading by hand or with ground equipment.