J4i- ■ 
collection, are strongly in favor of- the belief that it did not 
reach this locality before the last twelve months. Three assistant 
entomologists of the Natural History Survey, working respectively 
in northern, central, and southern Illinois, have not taken speci- 
mens to date. Hence, although present, it is still scarce and not 
widely spread in the State. 
GENERAL In order to determine the extent to which this spec^ es may have 
spread into the Middle States, letters were sent to entomologists 
in Kentucky, Iowa, Kansas, Missouri, Wisconsin, Indiana, Michigan, 
and Ohio. To date it is not known from the first five States named, 
even though Herri ck (Manual of Injurious Insects ,1925, p.270) says, 
"it is now distributed over much the same territory as C aspar agi 
except that it has not reached Calif ornia. " The soecies is recorded 
from Indiana, Michigan, and Ohio. Prof. Pettit ventured to state 
that it first entered Michigan from Ohio seven or eight years ago, 
or about 19lo. Mr. Eietz, Indiana, kindly furnished records which 
show that this beetle occurred in IToble County in the northeastern 
corner of that State in 1920, and at Cambridge City, Wayne County, 
near the Ohio border east of Indianapolis in the same year. 
Records for Ohio indicate its presence there earlier and also 
more widely spread than in Indiana and Michigan. Fink (Cornell 
Univ. Agr. Exp. Sta. Bui. 331,1913) summarized its distribution 
up to that time, showing that it had spread "as far west as Ohio, 
and as far north as to include the Niagara peninsula." T. L. Guyton 
(Ohio Agr. Exp, Sta. Mo. Bui., Vol. IV, p. 199,1919) indicates 
that it was not at all common in that year. The present writer did. 
not find it about Marietta, Ohio, during the seasons of 1919,1920, 
and 1921, during which years sons time was given to asparagus beetles. 
A. E. Miller, in his study of truck-crop insects at Chillicothe, 
Ohio, from 1922 to 1925, found two or three individuals in 192^. 
Whereas it was absent or rare in southern Ohio, Miller informed the 
writer that it had been reported commonly theretofore from the 
northern part of the State. 
According to Pink, 1. c. , this beetle was first observed near 
Baltimore, Md. , in 1S81, and spread north into Canada and into 
Delaware, Pennsylvania, New Jersey, Hew York, Connecticut , Rhode 
Island, Massachusetts, and Maine. It seems that the prevailing 
westerly winds operated to prevent its dissemination directly" west- 
ward, causing it to take a northwestward, north, or northeastward 
direction. When it reached the Great Lakes it probably crept along 
their southern shores and has gone at least to the Chicago area at 
present. This is shown by the fact that most of the records are for 
the northern parts of Ohio, Indiana, and Illinois, and for southern 
Micnigan. Prom that barrier line the species seems to be spreading 
southward and westward, appearing again to be deflected from a due" 
west direction by the west -inds of this region. When it has gone 
oeyond .he southern border of Lake Michigan it will presumably 
spread northward more Promptly into Wisconsin and Other north- 
western States. 
The paths over which insects of economic importance spread into new 
^^° ry ' and the ' factors determining these routes, must be re- 
garded as of much value. Here is a species in nrocess of spread 
