STUDIES ON PERILLUS BIOCULATUS FAB. 
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claimed that it was becoming so beneficial that spraying was hardly 
necessary. . . . . There seems to have been a northward spread 
of this insect, as it was not formerly known to occur as far north as 
Illinois, and here we have it in 1908 and 1909 in Michigan, and in 
Ontario in IgIt.” 
Caesar (1912) publishes concerning Perillus bioculatus in Ontario, 
as follows: “Perillus bioculatus var. clandus has been found in many 
counties this year [1911]. Evidently it ranged almost all over the 
southern and western part of the province, and, at least, as far east as 
Toronto. In some fields it was present in large numbers and destroyed 
many of the adult Colorado potato beetles and also the larvae.” 
Nash (1912) published the following: “One of the Soldier Bugs, 
Perilloides claudus, appeared in considerab'e numbers this year [1911] 
in the potato fields, where it fed upon larvae of the potato beetle. Early 
in August I found several of these bugs in the nymph stage feeding 
on Tussock moth larvae. Claudus has never been a common insect 
in Ontario, and why it should have become abundant and so generally 
distributed this year is a mystery.” 
In 1913 the writer found Perillus bioculatus abundant in Genesee 
County, N. Y., at which time the present studies were begun. They 
were carried on for four years in that locality. On making inquiries, 
one farmer reported having noticed the bugs at work in his potato 
field, at least two years earlier, or in 1911. As yet the species has not 
been recorded from the New England states but there seems to be 
no good reason why it should not move as far eastward as the Colorado 
potato beetle has gone. At the present time the eastern limit of distri- 
bution for the species must extend well into the eastern half of New 
York, altho the most easterly record known to the writer is that of a 
specimen taken at Ithaca, in 1915. 
In Minnesota, since the summer of rg19, the writer has found 
bioculatus fairly abundant in potato fields in the vicinity of University 
Farm. Specimens have also been received from Mendota, Northfield, 
St. Peter, Jordan, Center City, and St. Cloud. which would indicate 
that the species is well distributed in the central eastern half of ihe 
state. During the present year, 1923, Mr. C. E. Mickel has found 
bioculatus present in potato fields at Quamba, Kanabec County; 
Meadowlands, St. Louis County; and Thief River Falls, Pennington 
County. 
Methods of Rearing 
For rearing Perillus, the ordinary type of jelly glass was found 
to be a very convenient kind of cage. Holes punched in the lid fur- 
nish plenty of ventilation and at the same time prevent the potato 
