-t ^65 - 
Iii eastern JCIebra^a a,bout. jib’ <jf Mfestations came from 
sweetciover fields, -and ,tmplo\/§d sowii in coiii^or 
sorghum stuh’ble, whicti had.. "b, e'en .harrowed dr left s^andihi^, pioVed -an 
important source of infestattqng,, for H. hiT^'ttatua .'"; ^h-iorne Instances • . ' 
popula^ons of 300 per square .yard d.efeiqped'. in places. Other sources ' 
of infestations were the roadsideq^and'other Tield margiris,' sqddy hanksof- 
coulees, , and, alfalfa fields, ^^he'^^d^stributidu of the species in this area 
is described by Lindsay as "follows J "In west-centr^ Iowa the infestation 
was nredominantly . M, bivittatus , with, ocoasidnal areas where M.~ mexicanus 
was dominant;., in northwestern Missouri the infestation was negligible; in 
eastern Nebraska M. bivittatus predominated in sote' localities and ■ 
M. differentialis in others. Later, M. differentialis became the most im- 
portant in all but the northeastern counties, ' The M, bivittatus infestation 
in^Nebraska extended into soutfo- central South Dakota, notably in' Tripp, 
Gregory, and Charles Mix' Counties, thence eastward in reduced numbers, -where 
it was combined with M, differentialis . Just north of these counties there 
was a general infestation of M, mexic^us . In southwestern Minnesota only ' 
one small infestation was encountered, occurring in Rock Coxuity and ^first 
consisting of M, bivittatus and M. differentialis mixture, but following a 
severe hail and hatch of M. femur-rubrum it became predomihahtly M. mexicanus 
and M, femur-rub rum . The latter species also increased in importance in 
northwestern Iowa,*' 
Dissosteira longinennis Area 
This area included southeastern Colorado, southwestern Kansas, Pan- 
handles of Oklahoma and Texas, and the northeastern part of New Mexico, 
The survey supervisors for this area were L..A, Spain and D, K, Scharff, 
and the following discussion is based on their observations. 
Mr, Spain reports: "That portion of the Great Plains embodying the 
D, longipennis outbreak might be considered as an area of considerable 
diversity, from the aspect of topography, and as one of much similar! tyj ' " 
from the standpoint of natural vegetation, . Por the most part, the ^terrain 
is slightly rolling, short- grass range landy'"' called the plains grassland, 
varying from level plains pn the east to. the’ morb rough hill land with 
buttes and mesas on the west. Soils are predominantly sand and day loams - 
with very little organic matter. In the longipehni s region of the short 
grass or plains grassland, the natural grass is principally a mixture of 
grama ( Bputeloua gracilis ) and, buffalo grass ( Buchloe dactyloidesJ .- Wire 
grass ( Aristida long! seta ) appears in the flora in the easte'rn edge of 
D« longipennis area, and along the western edge admixtures of ring 
grass ( Muhlenbergia torrevi ^ and junegrass ( Koeleria cristata ) appear. 
Toward the southwest in New Mexico' black grama ( Boutelnua p-vionoda ) becomes - 
more and more abundant until it is the dominant species at the margin of 
the infestation. Other grasses of a more or less local nature contribute 
variation to the flora but the general dominance of grama-buffalo' -grass is 
characteristic of the D. longipennis area. It is estimated that more than 
90 percent of the D, longipennis infestation of 1939 hatched from rangb 
and pasture land where these short grasses were dominant. 
