- 214 - 
MICHIGAN 
Collections have been made in Michigan during the years 1935 to 1938, 
inclusive. This past season 4,608 specimens were collected in 5 environ- 
ments. There were 18 species represented in these collections, with im- 
mature forms making up only 3.43 percent. In all 5 environments, M. 
mcxicanus was "by far the most numerous and formed 68 percent of the total 
number of specimens collected. C annul a pellucida is second in relative 
abundance, and Ageneotettix deorum third. There is about the same relative 
difference in numbers between M. mexicanus and _C. pellucida in 1938 as 
there was in 1937, but Ageneotettix deorum has definitely increased its 
relative abundance. It supplanted M. f emur - rub rum for third place. 
Hatching of M, mexi canus began the latter part of April and dragged 
out through Hay and June. Heavy rains reduced nymphal populations, delayed 
and prolonged hatching, and interfered with the baiting. Most of the bait- 
ing was done in July when the hoppers were most active. The grasshopper 
potential in the 1938 survey was found to be about 85 percent of what it 
was in the 1937 survey. Although M. mexicanus was by far the most numerous 
and important grasshopper, yet it does not develop the migratorial tendencies 
in Michigan that it does in the Great Plains States. Infestations in 
Michigan are of local character and importance, perhaps because of the 
natural vegetation and agricultural practices found in Michigan. Numerous 
small pastures, with plenty of vegetation, and small farms interspersed 
among heavily wooded areas do not encourage much moving about, as do the 
broad, wide, open, sparsely vegetated lands of the Great Plains. 
