2 INSECTS INJURIOUS TO SUBTEOPICAL. 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 OAvn 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 Nevada foothills or the adjoining 

 i^lains 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. W. E. Hinds for identification, probably did not obtain the 

 true orange thrips {Euthrips citri Moulton), but some specimens of 

 EuthHps occidentalis Pergande, 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 auraniium var. 

 slnetisis (Washington Navel, Australian Navel (?), Thompson Im- 

 proved, Valencia Late, Mediterranean Sweet, Parson Brown, Ruby 



"Arizona Agricultural Experiment Station, Bulletin No. 5S, Citrus Culture in 

 the Arid Southwest, p. 319, 1908. 



*U. S. Department of Agriculture, Bureau of Entomology, Technical Series 

 No. 12, Part VII. 



