381 



The periodical outbreaks of Eutictix tcncUa, Baker (beet leaf-hopper) 

 are due to the migration of the adult insects in summer. The cultivated 

 area of San Joaquin valley is free from this pest from November to 

 April, and beets should be planted in December or January, so that the 

 foliage covers the rows before the insect returns in April. 



The total destruction of the sugar-beet industry in California is 

 threatened by the curly top disease spread by this leafhopper, and 

 it is urged that varieties of beets should be selected to obtain more 

 vigorous and resistant strains under Californian conditions. 



The results are given of a survey of the Santa Clara valley to locate 

 waters containing calcium, magnesium and chlorine, these being 

 undesirable for sprays and dips. A certain quantity of chlorine was 

 found to render the use of such water dangerous in applying acid 

 lead arsenate. Caustic soda is recommended to soften water rather 

 than soda ash. 



Crude oil emulsions proved more effective in controlling the winter 

 egg of the brown mite, Bryohia praetiosa (praiensis), than distillate 

 oils or lime-sulphur, though the latter checks fungi and the peach 

 twig-borer [Anarsia lineaiella] if applied before the buds open. 



Kaolin dusting mixtures are effective, and more convenient for 

 destroying thrips and certain Aphids than liquid applications, which 

 cannot be used on wet soils. 



Nematode pests thrive in warm countries, and Heterodera radicicola 

 and H. schachiii cause serious damage to potatoes, tomatos, beets, 

 peas, beans and other crops. Soils once infected are rarely freed from 

 the pest, and gardens become worthless. Disinfection of fields by 

 growing immune plants is difficult, as weeds continue to support the 

 Nematodes, and trap crops and poisons have proved ineffectual. 

 Wireworms also cause serious damage. Various species are found 

 in different localities ; little is known of their life-history, except in 

 the case of Limonius caUfornicus (sugar-beet wireworm), but no 

 satisfactory method of control has been found. 



CoxDiT (I. J.). The Kaki or Oriental Persimmon. — California Agric. 

 Expt. Sta., Berkeley, Bull. 316, December 1919, pp. 231-266, 

 20 figs. [Received 1st June 1921.] 



In the course of this paper dealing with the cultivation of persim- 

 mon (Diospyros) in California, the following insect pests are noted as 

 causing slight damage : — the barnacle scale [Ceroplastes cirripedi- 

 formis], the white peach scale [Aiilacaspis penfagoiia], the codling 

 moth [Cydia pomonella'], and Schizura concinna (red-humped cater- 

 pillar). 



In 1919 trees imported from Japan were destroyed owing to being 

 infested with the eggs of a cicada, Mantid eggs, Pseudococciis sp., and 

 an Aegeriid moth, Sannina uroceriformis, Wlk. 



Strict quarantine measures should be adopted to prevent importation 

 of the following pests : Kakivoria flavofasciata from Japan, fruit-flies 

 from New South Wales, and Oncidcres cingidata (twig girdler), San 

 Jose scale [Aspidiotus pcrniciosus] and the orange wYiiie^y [Dialeurodes 

 citri] from the Southern United States. 



