THE OUTBREAK OF 1907. 37 
fields of fall oats and more or less volunteer grain in other fields, all of which consti- 
tuted breeding grounds for the pest during the preceding autumn, and from which 
winged individuals migrated and established new colonies in other fields; these, 
owing to influence of weather on the development of parasites, caused the most of the 
injury in wheat. 
We received a letter with specimens from Mr. L. M. Smith, Mr. 
Sherman's assistant, at Newport, Carteret County, N. C, stating that 
he found a small field of oats in the outskirts of town that was con- 
siderably damaged by Toxoptera. This county is on the coast and 
Newport has an elevation of 19 feet. From this it seems that in all 
probability Toxoptera covered the entire State. 
The senior author also found Toxoptera in destructive abundance 
at Midlothian, Chesterfield County, Va., in a small meadow of orchard 
grass. Mr. J. L. Phillips, the State entomologist, reported a slight 
outbreak at Cloverdale, Botetourt County, Va., in rye, and stated 
that considerable damage had been done in some parts of the field. 
One undetermined Aphidius was found at Midlothian, while none was 
reported from Cloverdale. 
There was an outbreak of Toxoptera in the bluegrass lawns north 
of the buildings of the Department of Agriculture at Washington, 
D. C, in July, 1907. The infested area (see PI. II, fig. 2) was appar- 
ently confined to the space of about an acre, where it was excessively 
abundant; outside of this area practically no Toxoptera could be 
found. This offered a good opportunity to test spray materials and 
a number of experiments of this kind were carried on. 
Dr. Howard, personally, found Aphidius present in this infested 
area though in very limited numbers. In all probability this was 
Aphidius avenaphis Fitch, as we have since found this species in this 
exact locality but at no time have we found A. testaceipes Cress., 
which, until Mr. Viereck revised this group, had been considered to 
be Lysiphlebus tritici Ashm. We did not, in 1907, find any species of 
Aphidius present and did not know that Dr. Howard had done* so, as 
he soon after sailed for Europe and at the time Circular 93 of this 
bureau was published the statement as to its nonoccurrence was not 
called to his attention in time to be corrected and he did not inform 
us of his find, supposing that we knew of it already. Mr. Kelly, how- 
ever, found Allotria sp. present there in 1907, and we have since found 
this to be a parasite of Aphidius, which may account for the fact that 
the latter was present in such limited numbers. In 1908 Aphidius 
avenaphis was quite plentiful there, although specimens were not 
preserved, while Allotria sp. was found sparingly on the grounds else- 
where in the vicinity. As Toxoptera attracted no attention in this 
area on the grounds of the Department of Agriculture in 1909 we 
have no records for that year. In 1910 Toxoptera was again injuri- 
ously abundant on the same area and no Aphidius could be found, 
while Allotria sp. was still in evidence. It seems possible that condi- 
