Departmental Activities. 109 



DEPARTMENTAL ACTIVITIES 



December, 1920. 



(Note. — The work of the several Divisions and Schoolftnf Agriculture covers a wide 

 range of agricultural industry in the Union, and we give hereunder notes and observations 

 from certain of them treating with matters of special interest coming under their purview 

 during the month. The object of these notes, which are not concerned with general routine 

 work, is to inform the farmer of such matters as are calculated to be of interest and helpful 

 to him at the present time. — Editor.) 



THE DIVISIONS. 



ENTOMOLOGY. 



Black Scale Parasites in Cahfoniia. — The black scale (Saissetia 

 oleae) is much the worst scale pest of citrus trees in California, and 

 it is primarily for its suppression that most fumigation of citrus trees 

 is carried out in that State. The scale occurs widely in all four 

 Provinces of the Union, but is nowhere a pest and is seldom found in 

 an orchard. Its unimportance in South Africa is attributed by the 

 Division of Entomology to the efficiency of native parasites which, 

 for nearly twenty-five years, official entomologists of this country have 

 made intermittent efforts to get introduced into California. One of 

 the important parasites, Scutellista cyanea, was established in the 

 State from a sending of material made twenty years ago, but although 

 't proved a A^aluable introduction, its good work was soon found to be 

 insufficient materially to obviate the need to fumigate citrus trees. 

 The efforts to get other of the parasites established, through the 

 assistance the Division was able to give, not being successful, the 

 California State Board of Agriculture finally adopted a recommenda- 

 tion long urged by the Division to send a special entomologist to 

 South Africa to collect and forward material. For about eighteen 

 months a California officer has been located in South Africa, with 

 headquarters at the Division's field station at Eosebank, near Cape- 

 town, and much is still expected from his work. Meanwhile one 

 of the much-wanted South African parasites has been bred out and 

 colonized in California from some material collected in Australia. 

 In a recent letter to the Division of Entomology, the Chief Ento- 

 mologist of the Board of Agriculture wrote : — ■ 



" You may be interested to know that the black scale 

 parasite, Apltycus lounsbuiyi, has become established in southern 

 California and is doing a very remarkable work, particularly 

 along the coast. I have visited the orchards near Santa Paula, 

 where we have been colonizing the parasite, and the work of this 

 insect is exceeding my fondest expectations. In my opinion, 

 there is no question but that the black scale is going to be handled 

 by the use of natural enemies in the coast region of California, 

 thus resulting in a saving of a good manv hundred thousands of 

 dollars." 



