272 



Van der Goot (P.) & Roepke (W.). Beknopt Verslag der HelopeJtis- 

 bijeenkomst (28 Juli 1916). [A brief Report of the Helopeltis- 

 Conference of 28tli July 1916.]— Mecferf. Proefstation Midden- 

 Java, Salaliga, no. 29, n. d., 22 pp. 



The ground covered by the discussions at this meeting has already 

 been dealt with in several papers on Helopeltis [see this Review, Ser, A, 

 iv, p. 442 ; V, 413, 570]. 



Carballo (E.). Informe acerca de las Causas de la Infertllidad de los 

 Olivares del Ternimo de Jerez y del Lindante de Arcos de la 

 Frontera. [Report on the Causes of Infertility of Olive Trees in 

 the Districts of Jerez and Arcos de la Frontera.] — Bol. Agric. 

 Tecnica y Economica, Madrid, x, no. Ill, March 1918, pp. 217-230. 



The chief disease of oUve trees is caused by a fungus that follows 

 upon the attacks of Saissetia {Lecanium) oleae, which clusters under 

 the leaves and on the branches of the trees. For the district under 

 discussion the only control that has been found effective is Bordeaux 

 mixture and turpentine. It is considered of the utmost importance 

 to cultivate the trees and plant, them in suitable positions only, so 

 that the chief causes of disease, namely, excessive moisture and lack 

 of ventilation, air and light, may be eliminated. 



Dacvs oleae (olive fly) is the cause of very great loss to ohve-growers, 

 severe infestations occurring periodically from unknown causes. A 

 short account of the life-history is given. There is no known method 

 of controlUng this fly that is cheap and efficacious. It has been suggeS"- 

 ted that the oUves should be gathered early, before the larvae of the 

 last generation have left the fruit, and that if all are not killed by 

 this means in one year it should again be practised in the following 

 year. After early gathering of the fruit it should be crushed imme- 

 diately and the refuse left at the oil-mills should at once be burnt. 

 It is essential, for this measure to be successful, that all olive-growers 

 in a given region should make this early harvest, otherwise the opera- 

 tion would be absolutely useless. The only other possibility of exter- 

 minating this pest is to wait until it is destroyed by climatic conditions, 

 as in the year 1897, when unusually warm weather in February and 

 March caused a rapid development of D. oleae, which arrived at 

 maturity, but could find no olives on which to oviposit as these had 

 not yet appeared. In combating these insect pests, insectivorous 

 birds should be carefully protected. 



LEGISLATION. 



Amendment no. 1 to Quarantine Order no. 29, Alfalfa Weevil. — Mthly. 

 Bull. Cal. State Commiss. Hortic. Sacramento, vii, no. 3, March 

 1918, p. 170. 



As Hypera variabilis {Phytonomus posticus) (alfalfa weevil) has now 

 invaded Delta County, Colorado, this amendment dated 31st January 

 1918 has been issued in Cahfornia to include this County in the list 

 of quarantined areas. 



