U. S. D. A., B. E. Bul. 95, Part VII. Issued October 16, 1912. 
PAPERS ON CEREAL AND FORAGE INSECTS. 
THE ALFALFA LOOPER IN THE PACIFIC NORTHWEST. 
(Autographa gamma californica Speyer.) 
By J. A. Hystop, 
Agent and Expert. 
INTRODUCTION. 
The first record of this moth of economic importance is an un- 
published note by Mr. Theodore Pergande? made June 29, 1895, 
wherein he records having received from Mr. E. W. Baker, of Grand 
Junction, Colo., a few specimens of the larve of a Plusia, determined 
on the note as “Plusia gamma (?% ),” with the statement that the larve 
do much damage to the leaves and blossoms of alfalfa. Material was 
not preserved, so actual specific determination is impossible. As 
Plusia gamma lL. is a European species, presumably it was P. gamma 
californica Speyer, now known as Autographa gamma. californica. 
The depredations of this species have not as yet been sufficiently 
serious to cause damage in the Palouse region of Washington and 
Idaho, although its attacks on alfalfa and clover have attracted the 
attention of many ranchers. The larve are usually very numerous in 
the early spring and gradually increase in numbers until the first 
hay cutting, when they appear to reach the maximum. They do not 
seem to be inconvenienced by the removal of the hay crop, but imme- 
diately turn their attention to the young second growth, on which 
larve are to be found throughout the summer until the early frosts. 
The alfalfa looper in this locality has been held in check by a 
number of parasites and a disease, but any change in environmental 
conditions which might tend to reduce the efficiency of these natural 
checks or accelerate the reproduction of these moths would undoubt- 
edly cause a serious outbreak, such as occurs periodically with the 
highly parasitized white-marked tussock moth, Hemerocampa leu- 
costigma S. & A. It does, however, offer an excellent illustration — 
of the statement, so often made, that many injurious insects are held 
in check by their parasites. Such cases as the above justify the arti- 

1 Bureau of Entomology Notes, No. 6692. 
109 
