August, '19] SEVERIN: BEET LEAFHOPPER 315 



cream colored forms of the spring brood, but in April the pale green 

 or cream colored insects greatly out-numbered the dark bugs. No 

 attention has been given to the canyons, foothills and mountains 

 surrounding the Imperial Valley. 



In the Imperial Valley, E. tenella has been bred from the Lowland 

 Purslane, Australian Saltbush, and .4. elegans. During the winter 

 and spring only 15 beet leafhoppers were taken on 7 species of desert 

 plants, 3 of which were perennial Atriplex. In the cultivated area, 

 the insects were collected on 17 species of plants, 6 of which belong to 

 the Saltbush family. The pest was most abundant on different species 

 of Atriplex and Chenopodium. 



V. San Joaquin Valley 



Natural Breeding Area 



"While the writer was engaged in a grasshopper survey of the state 

 of California in the spring of 1917, large numbers of Jassids were some- 

 times found on the plains and foothills. Two trips were taken in the 

 San Joaquin Valley, the first on April 23-May 7, and the second on 

 May 21-28. A small paper bag was fastened in the bottom of the 

 insect-net and the insects which were swept from the v^egetation 

 dropped into this bag. A few bags of these sweepings were examined 

 by Mr. Thomas but no E. tenella were found and on account of other 

 work the material was set aside for examination during the winter. 

 Up to the present time 250 bags of sweepings collected in various 

 localities on the plains and foothills of the San Joaquin Valley have 

 been examined with the following results: 



April 25/17. 12 miles south Los Bancs, 1 dark female E. tenella. 

 April 25/17. 17 miles south Los Banos, 1 dark female E. tenella. 



Mr. Thomas discovered large numbers of adults of E. tenella on 

 pasture vegetation on the plains in the vicinity of Coalinga on May 9, 

 and Professor R. E. Smith found nymphs commonly on stones in the 

 warm sunshine. A trip was made to determine whether the pest was 

 local or general on pasture vegetation throughout the San Joaquin 

 Valley. On May 16-21, about 700 miles were covered in an automo- 

 bile by W. J. Hartung, Thomas and the writer and from 1-50 leafhop- 

 pers were taken with about 25 sweeps of the insect-net on Ked Stem 

 Filaree (Erodivm. cicntanum) growing on the plains, canyons and foot- 

 hills in v^arious localities on the west side of the San Joaquin \'alley. 



G. T. Scott and 1'homas found a congregation of the l)cet leafhopper 

 on Artiplex coronata on June 22, growing among the Spiny Saltbushes 

 (Atriplex covferlifoJia'} at Helm. On this date the Filaree was dry with 

 few exceptions at Coalinga and most of the hoppers taken were males. 



