2 BULLETIN 438, U. S. DEPARTMENT OF AGRICULTURE. 
Matthew Cooke (1)'in the year 1881. At that time it was reported also 
from Natoma and Santa Clara, Cal. In the spring of 1909 it was 
‘quite common in the vicinity of Stanford University, Cal., and in 1911 
it was a pest in Tehama County, Cal., besides being generally dis- 
tributed throughout the central counties, both on the coast and in 
the great interior valleys of Sacramento and San Joaquin? (3) As to 
neighboring States, Prof. H. F. Wilson, of the University of Wisconsin, 
in a letter reports the msect attacking pear foliage in Oregon (1913); 
Dr. A. W. Morrill, State entomologist of Arizona, states in a letter 
that Arizona is free from the insect (1913); Prof. C. P. Gillette states 
that the insect does not appear to live in Colorado. In Washington 
it was found in pear orchards in the Wenatchee Valley in 1914 and 
1915, being particularly abundant in an orchard about 6 miles from 
Wenatchee, but careful inquiry did not lead to the discovery of other 
orchards having more than a scattering infestation. 
Mr. C. L. Marlatt, in describing this insect, states that Dr. J. A. 
Lintner, former State entomologist of New York, reported an unde- 
termined sawfly larva as being injurious to pear in a nursery at 
Geneva, N. Y., im May, 1894. Mr. Marlatt says (2)! it is probable that 
this is the same species, but as it has not been reported since, so far 
as known, the identification of the Geneva specimens remains doubt- 
ful; however, the collection of a specimen at Brockport, N. Y., indi- 
cates that it may be found in the East. 
POSSIBLE ORIGIN. 
An attempt was made in Washington to ascertain the natural 
hosts of the pear leaf-worm. The fact that it is found in various 
localities throughout a range of a thousand miles would indicate that 
it is a native species. Two wild plants related to the pear are to be 
found in the vicinity of Wenatchee, Wash. These are the service 
berry (Amelanchier cusickit Fern.) and the thorn apple (Crataegus 
bremspina Dougl.). Plants of both species were searched carefully 
for larve of the sawfly several times in May. Nothing was found 
on the service berry, but the thorn apple yielded a number of green 
larve very similar to those on pear. They differed, however, in 
being a more shiny green, and in having scattered brown dots laterally 
and dorsally on the thorax. A number of these were reared, but the 
adults have not yet emerged. It is very probable that they belong 
to a distinct but closely related species. 
Nearly full-grown larve of the pear leaf-worm were placed upon 
twigs of both the service berry and the thorn apple. Those on 
the former fed a little, but soon dropped off and died, while the 
larvee on the latter at once began to feed, and several of them matured 
and spun cocoons. From this it may be inferred that the pear leaf- 
1 Figures in parenthesis refer to “Bibliography,” p. 23. 
