52 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
Tulare and Fresno fruit districts, but it was found after a careful 
investigation that none of these fruit areas was infested. In the one 
case, at Newcastle, the injury was evidently that of the blossom pear- 
blight and not a single pear thrips could be found in the whole region 
at a time when the insects should have been in evidence in greatest 
numbers. A few thrips of another species (Huthrips occidentalis 
Pergande) were found in pear and cherry blossoms in this locality, but 
this insect is not injurious to fruits, and its presence in blossoms is of 
no consequence. ‘Thrips from pear blossoms at Visalia were found to 
be of the species Huthrips tritici Fitch, which also is not usually injuri- 
ous to fruit trees. The present infestation, then, is confined to the 
region around and closely adjoining the San Francisco Bay. It 
extends south through the Santa Clara Valley and into Hollister, San 
Benito County, north through Alameda, Contra Costa, Solano, and 
Yolo counties, and also occurs in some rather small areas along the 
Sacramento River. The area of deciduous fruits, about 60,000 acres, 
in the Santa Clara Valley, is practically all more or less infested by the 
thrips; and the other infested orchard sections, such as Hollister, 
Walnut Creek, and Concord, in Contra Costa County, and Suisun and 
Vaca orchards and others along the Sacramento River, also include 
many hundreds of acres. 
The original home of this species is still in doubt. Several men 
have expressed the opinion that it is of European origin, but, accord- 
ing to Doctor Buffa, the insect does not occur in Europe, and after 
examining the species he believes it to be of eastern origin, suggesting 
China as possibly its original home. 
The various thrips which are seen in roses and in other flowers, and 
which can be found at almost any time of the year, should not be 
mistaken for the pear thrips, which is distinctly a fruit-tree pest and 
does not attack grass, weeds, or cultivated flowers. It has, once or 
twice, been collected from leaf clusters of rose bushes, but this is not 
common. The name “pear thrips” was given because the insect was 
first found in pear blossoms, but this does not indicate that it attacks 
pear trees only. The injury on prunes and other fruit trees is equally 
as serious as that on pears. Thrips should not be confounded with the 
vine hopper Typhilocyba comes Say, an insect which is wrongly called 
“thrips,” but is not a thrips at all. The term “thrip,’’so commonly 
used, is also erroneous, as the word ‘‘thrips” is both singular and 
plural. 
CHARACTER OF INJURY. 
FEEDING INJURY BY ADULTS. 
Adult thrips appear on trees during late February and early 
March, when the buds are just beginning to open (Pl. IV). They 
remain on the tree until late in April and are thus feeding all through 
