"Z INSECTS INJURIOUS TO SUBTROPICAL. FRUITS. 
mology the use of their orchards for experimental and demonstration 
purposes; and they would express their indebtedness to the large 
number of orange growers in Tulare County who have put into effect 
in their own orchards the recommendations of the Bureau, thereby 
demonstrating the value of the spraying treatments advised. 
ORIGINAL HOME AND DISTRIBUTION. 
The orange thrips is probably native to North America. Its natu- 
ral habitat is probably the Sierra Xevada foothills or the adjoining 
plains of the southern San Joaquin Valley, and it was no doubt 
attracted from its natural food plants by the more succulent and 
luxuriant orange trees. This insect is distributed throughout the 
entire orange belt of the San Joaquin Valley and has been collected 
in several places in Southern California and at Phoenix, Ariz., by 
the senior author. The infestation in Arizona embraces orange 
groves in the Salt River Valley surrounding Phoenix, and was re- 
ported upon by Prof. J. Eliot Coit in a bulletin of the Arizona Agri- 
cultural Experiment Station. This gentleman, in sending specimens 
to Dr. TV E. Hinds for identification, probably did not obtain the 
true orange thrips (Euthrips citri Moulton), but some specimens of 
Euthrips occidentalis Pergancle, which is found occasionally upon 
citrus trees, but which rarely causes any serious injury. The true 
orange thrips was described as a new species by Mr. Dudley Moulton 
in a bulletin of the United States Department of Agriculture, issued 
February 11, 1909. & 
The orange thrips has also been reported from Hermosillo, Sonora 
Province. Mexico, but the writers have not been able to obtain speci- 
mens from that locality. 
The occasional scarring of oranges in the north-central portion of 
California is caused by the grain thrips {Euthrips tritici Fitch) , and 
not by the orange thrips. 
FOOD PLANTS. 
Although the orange thrips, when described, was thought to infest 
only citrus trees, the writers have taken it from a number of other 
host plants. The following list shows the wide range of food plants 
upon which this insect can exist : 
Of citrus fruits the following are affected: Citrus aurantium var. 
sinensis ('Washington Xavel. Australian Xavel (?), Thompson Im- 
proved, Valencia Late, Mediterranean Sweet, Parson Brown, Ruby 
a Arizona Agricultural Experiment Station, Bulletin No. 58, Citrus Culture in 
the Arid Southwest, p. 319, 1908. 
6 U. S. Department of Agriculture, Bureau of Entomology, Technical Series 
No. 12, Part VII. 
