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GRASSHOPPERS,— During the summer end fall of 1941 economic numbers of a 
second generation of Melanoplus mexicanus (Sauss.) developed in southeastern 
Arizona, southwestern Iowa, northwestern Missouri , southern Nebraska,, eastern 
Colorado, western Kansas, the Oklahoma Panhandle, and the Texas Panhandle as 
far south as Lynn County, The second-generation -area, of Nebraska, Colorado, 
and Kansas had adult first-generation populations ranging from light to threat** 
ening. Nymphs of the second generation were first observed in Hamilton County, 
Tex., on June 23. Most of " the hatch occurred during the month of August and 
v/as practically completed by September 5» In Kansas and Colorado, as in the 
1940 season, many eggs developed' rapidly top the point of hatching as early as 
August 15, then went into an aestivation period which carried them into the 
usual winter - hibernation* Nymphal- populations of the second generation reached 
a maximum about September 5* when populations were, found to average 50 per 
square yard in. alfalfa and 75 per square yard. on the margins. Relatively smallei 
populations were found in small grains and weedy areas in crop land in Colorado, 
Throughout the remainder of the infested area populations in these environments 
averagedl5 per square yard in the fields and J>0 per square yard on the margins. 
Mortality of nymphs was negligible over the entire infested area and second- 
generation nymphs developed rapidly, the average nymphal period being 6 weeks, 
and most of them had reached the adult stage on. October Nymphal migrations 
became general by September 10 and resulted in some marginal damage to fall 
wheat. Crop, damage as a result of nymphal feeding was heaviest in alfalfa. 
First a.dults of the second generation appeared about . September 1 and more than 
90 percent were adults on October 5t approximately 10 days earlier than was the 
case in 1940 in this- area. Flights were first reported on September 10 in 
Kansas and Texas. The flights were predominantly to the south and southwest, 
in the direction of the prevailing winds, The most extensive flights occurred 
on clear days when a northerly wind \^as blowing. The second-generation flight 
activity resulted' in a general reduction of the populations . in Nebraska, north- 
ern Colorado, and por them Kansas, and a, general increased population in south- 
western Kansas, eastern Baca County, Colo., to the Oklahoma Panhandle and most 
of the Texan Panhandle. Practically no previously uninfested areas, however, 
were infested as the resul.t of flight. Oviposition became general over the area 
by October 1 and continued to about November 1 in Nebraska., Colorado, and 
Kansas, and to November 20 in Oklahoma and Texas, Egg ‘surveys in the southern 
part of the second-generation a t rea indicate that light to Very severe infesta- 
tions may be expected in 1942, • 
Aeoloplus turnbullii (Thos.) became reduced by disease to insignificant 
numbers in Kansas, southern Nebraska, and eastern Colorado, M, diff erentialis 
(Thos.) has increased in relative importance by populations building up in the 
northern part of South Dakota and in localized areas in southern North Dakota 
and Montana. M. bivittatus (Say) is the predominant species in marginal condi- 
tions in large areas in northwestern Minnesota, Montana, North Dakota, south- 
central South Dakota, and Wisconsin. 
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Grasshopper surveys conducted in the fall of 1941 indicate that threaten- 
ing to severe infestations mav occur in parts of Colorado, Kansas, Minnesota, 
Montana, Nebraska, North' Dakota, Oklahoma, South Dakota, and Texas. Approxi- 
mately 29,000 tons of bait have been estimated 'as needed for these Stales in 
1942 and approximately 3»500 tons have been estimated for 12 other Western and 
Central States. The total estimate of 3^,470 tons for 1942, as compered with 
