August, '19] SEVERIN: BEET LEAFHOPPER 321 



on curly leaf beets. In all probability, the females wintering over in 

 the cultivated territory deposited their eggs and died, and the nymphs 

 which were observed on April 22, hatched from these eggs. 



When to Plant Beets 



The fact that most of the beet leafhoppers leave the cultivated area 

 in the autumn has an important bearing with reference to the time of 

 planting beets. Sugar beet agriculturists are well aware of the fact 

 that when beets are planted in November, December and January in 

 the San Joaquin Valley, if weather conditions are favorable for plant- 

 ing early, a good crop can usually be obtained. The weather condi- 

 tions are the determining factor with reference to planting from No- 

 vember to January. Last year no heavy rains fell in the San Joaquin 

 Valley until February 22, and hence early planting was not practicable. 

 The present rainy season started unusually early and heavy rains fell 

 on September 11-13. The most serious objections to planting early 

 are as follows: (1) the young beets are sometimes destroyed by frost 

 necessitating replanting; (2) about 75 per cent of the beets planted in 

 November, 50 per cent in December and 15 per cent in early January 

 develop seed stalks which slightly reduces the sugar contents and 

 furthermore, these beets are woody and difficult to slice. 



In the Imperial Valley E. tenella was abundant on the Australian 

 Saltbush during the winter. A similar observation was made on sev- 

 eral acres of this perennial Atriplex growing near Wasco but 75 per 

 cent of the specimens collected on December 10, and 82 per cent on 

 February 16, proved to be males. Evidently the adults do not leave 

 this plant in October and fly to the plains and foothills. The Austra- 

 lian Saltbush was introduced from Australia as a forage plant and birds 

 are said to distribute the seeds. If this plant spreads to the beet 

 districts there is a possibility that early planted beets may become 

 badly blighted. 



Do heavy rains kill the beet leafhopper? At Manteca 3f inches of 

 rain fell before the return flight of the insects to the natural breeding 

 grounds had commenced. In sugar beet fields, an occasional adult was 

 observed with wings spread and partly embedded in the sandy soil 

 below the leaves of blighted sugar beets. Dead specimens were found 

 in the folds and below dried leaves. Dead hoppers partly embedded 

 in the soil were also commonly taken below branches of A. bracteosa 

 and in 40 minutes, 30 adults were collected. Evidently the creatures 

 crawled below the branches to escape from the rain. Dead nymphs 

 were rarely found but these were probably difficult to detect. An 

 examination of the bugs under a binocular microscope showed that 

 50 per cent had been parasitized. The material was dry and could not 



