370 INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



Food Plants. — Wheat appears to be the only recorded host plant of 

 this insect. 



Control. — Since the larvae hibernate in the straw or stubble in the 

 field, it is very important to cut the grain as low as possible and to 

 plow the stubble under deep. The straw from the infested fields should 

 be burned during the winter, as the larva? mature as well in the mow 

 as in the field. Crop rotation is also recommended. In controlling this 

 pest it is important for whole sections to cooperate in the methods 

 adopted. Not nearly as much can be accomplished by a single indi- 

 vidual as by a community. 



Natural Enemies.— In his work on this pest, J. S. Houser 26n records 

 the following natural enemies : The hymenopterous parasite (Ditro- 

 pinotus aureoviridis Crawford), the predaceous mite (Pediculoides 

 ventricosus Newport) and the fungous disease (Sporotrichum globuli- 

 ferum). All of these attack the larval and pupal forms. 



Aphycus sp. (Family Encyrtidse) 270 

 (Fig. 368) 



Description. — This is a small, yellow, four-winged insect as shown 

 in Fig. 368. 



Distribution. — It is especially abundant in the southern part of the 

 State and also found in the central and northern parts. 



Fig. 368. — Aphycus sp. which commonly attacks the soft 

 brown scale, Coccus hespcridum Linn. Greatly enlarged 

 adult. (After Howard, U. S. Dept. Agric.) 



Hosts.— This species is a very important enemy of the soft brown 

 scale {Coccus hesperidum Linn.), and when abundant is a very efficient 

 check to this pest. It also occasionally attacks immature forms of the 

 black scale, Saissetia olece (Bern.). 



209 Bul. 226, Ohio Agrcl. Exp. Sta., pp. 196-198, 1911. 



2T0 This species has been commonly known as Aphycus flavus (Howard), but accord- 

 ing to P. H. Timberlake it is Aphycus sp. near flavus. (Jr. Ec. Ent. VI, pp. 294-295, 

 1913). 



