UNITED STATES DEPARTMENT OF AGRICULTURE 



I BULLETIN No. 256 



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Contribution from the Bureau of Entomology 

 L. O. HOWARD, Chief 





Washington, D. C. 



PROFESSIONAL PAPER 



July 27, 1915. 



KATYDIDS INJURIOUS TO ORANGES IN CALIFORNIA. 



By J. R. Horton and C. E. Pembeeton, 

 Scientific Assistants, Tropical and Subtropical Fruit Insect Investigations. 



INTRODUCTION. 



There are at the present time in the San Joaquin Valley of Cali- 

 fornia over 43,000 acres of land devoted exclusively to the cultivation 

 of citrus. The citrus strip lies along the Sierra foothills between 

 Bakersfield and Fresno. Although some citrus trees have been grown 

 in this area for more than 25 years, most of this great acreage has been 

 planted in the last 15 years. The transformation of this strip of land 

 from a semiarid grain-growing belt into an irrigated fruit-growing area 

 has so changed the status of certain formerly obscure species of insects 

 native to the locality as now to bring them into prominence as pests. 



One of the more important of these species is the fork-tailed katy- 

 did, Scudderiafurcata Brunner. The amount of damage done by this 

 insect has increased considerably since 1910, when it first came to the 

 attention of the senior author. In 1912 it caused a loss in several 

 orchards of a full fourth of the crop. 



Associated with the fork-tailed katydid in the orange groves and 

 closely resembling it is the angular-winged katydid, Microcentrum rhom- 

 bi folium (Sauss.). This insect is also responsible for a certain amount 

 of injury to orange trees annually, feeding voraciously, as it does, 

 upon the leaves. It is, however, of much less importance than the 

 former, and is treated here rather because of close association with and 

 resemblance to the fork-tailed katydid than on account of its economic 

 importance. No distinction has heretofore been made between these 

 two species in the orange groves of California, 



THE FORE-TAILED KATYDID. 

 NATURE AND EXTENT OP INJURY. 



The fork-tailed katydid (Scudderia furai/a lirunner), so named from 

 the peculiar forked appendage ;ii the tip of the abdomen in the male, 



i di erlptfons of two tag lerious damage to oranges In California are 



ed in II,'. bulletin. Bemedie and method n discussed, 



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