INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



229 



THE BLACK LADYBIRD BEETLE 



Rhizobius centralis Erickson 



(Fig. 215) 



Description. — The adults are smaller than those of the common red 

 ladybird beetle, rather oval in shape, black and covered with fine, erect 

 hairs which give them a grayish appearance. 

 They are about | inch long. The abdomen is 

 salmon-colored. The larvae are dark brown 

 or black and covered with many spines. 



Distribution. — This beetle occurs through- 

 out the entire State where the black scale is 

 at all common. It was imported by Albert 

 Kcebele, especially as an enemy of black 

 scale (tiaissctia olece). 



Hosts. — The larvae and adults feed upon 

 the young and eggs of the black scale (Sais- 

 setia olcce), the hemispherical scale (Sais- 

 setia li< misphcerica) , various mealy bugs 

 (Pseudococcus spp.) and many of the 

 armored scales. 



Scymnus guttulatus Leconte 



(Fig. 216) 



Description. — The adults are oval-elon- 

 gate in shape and scarcely i inch in length. 

 The general color is black, 

 mottled w i t h reddish- 

 brown, as shown in Fig. 

 216. The body is cov- 

 ered with fine, short 

 hair. The larva? are about 

 \ inch long with yellow 

 bodies, which are entirely 

 covered with long, white, 

 cottony filaments. T h e 

 nymphs remain in the old 

 larval skins in secluded quarters throughout 

 the pupal stage. 



Distribution. — This is a native species, 

 occurring throughout the entire State, espe- 

 cially upon oak trees. It has often been 

 distributed by the State Insectary. 



Hosts. — The larva? and adults work upon various native mealy bugs 

 as well as upon the citrus mealy bug ( Pseudococcus citri) and the long- 

 tailed mealy bug (Pseudococcus longispinus) . . 



Fig. 216. — Scymnus 

 guttulatus Lee. Adult 

 female, enlarged five 

 times. (Author's illus- 

 tration, P. C. Jr. Ent. ) 



Fig. 215. — The black lady- 

 bird beetle, Rhizobius ventralis 

 Er. Larva and adult, greatly 



enlarged. (Author's illustra- 

 tion. P. C. Jr. Ent.) 



