UNITED STATES DEPARTMENT OF AGRICULTURE 



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1 BULLETIN No. 902 



Contribution from the Bureau of Entomology 

 L. O. HOWARD, Chief 



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Washington, D. C. 



PROFESSIONAL PAPER 



October 22, 1920 



THE WESTERN CABBAGE FLEA-BEETLE. 1 



By F. H. Chittenden and H. 0. Marsh, 

 Truck-Crop Insect Investigations. 



CONTENTS. 



Nature of injury 1 



Description 2 



Distribution 3 



Reports of injury 4 



Food plants 7 



Seasonal history 8 



Life history and habits 9 



Page. 



History and literature 13 



Natural enemies 13 



Control 14 



Recommendations 17 



Summary 20 



Literature cited 21 



NATURE OF INJURY. 



An insect enemy of cabbage, turnip, and other cruciferous crops, 

 known as the western cabbage flea-beetle, ranks as a most trouble- 

 some pest in the region which it inhabits. 2 



It is primarily an enemy of gardens, but quite too frequently 

 becomes a pest in large commercial plantings. The chief injury is 

 done by the overwintered beetles attacking turnip, radish, and other 

 cruciferous vegetables just as they are coming through the ground, 

 and by the beetles of the first generation, which are usually at the 

 maximum of their destructiveness during June and July. The beetles 

 appear suddenly, and frequently in incalculable numbers, and large 

 areas are completely devastated before the grower becomes aware of 

 their presence. 



Although the larvae feed on the roots of cruciferous vegetables, 

 they cause little appreciable damage. 



The beetles are by no means confined in their injurious attacks to 

 cabbage and other cole crops, since when they occur in unusual 

 abundance they attack most forms of vegetable crops, including 

 beans, peas, table and sugar beets, mustard, kale, and rape. As with 



1 Phyliotreta pusilla Horn; family Chrysomelidae, order Coleoptera. 



2 This insect was under observation by the junior author (deceased) from 1909 until 1917. at Rocky Ford, 

 Colo. 



1832°— 20 1 



