106 



CALIFORNIA STATE COMMISSION OF HORTICULTURE. 



scales. Coccinella oculata is a still larger form often taken for the 

 "twice-stabbed" ladybird. Exochomus pilatei, "Pilate's ladybird," also 

 resembles the "twice-stabbed," but the under side of the abdomen is 

 black instead of red. It feeds on black scale, but does not increase 

 rapidly. Psyllobora 0-maculata, the "20-spotted ladybird," is a com- 

 mon species, feeding on young scale and the red spider. 



Of the ladybirds introduced by the State Commission of Horticulture, 

 Vedalia cardinalis, Rhizobius ventralis, R. twoombeze, Novius koebelei, 



Orcus chalybeus, Cryptolse- 

 mus montrouzieri, Scymnus 

 vagans, S.marginicola, Rhizo- 

 bius debilis, Rhizobius lopan- 

 tha, and Hyperaspis lateralis 

 have proved the most suc- 

 cessful. Vedalia cardinalis 

 and Novius koebelei have com- 

 pletely subjugated the cot- 

 tony-cushion scale. Orcus 

 chalybeus is effective against 

 the yellow scale. Rhizobius ventralis is a very useful destroyer of the 

 black scale. Scymnus vagans is an enemy of the red spider. Rhizobius 

 lopantha makes some headway against the purple scale, and Cryptolssmus 

 m.ontrouzieri cleans up the mealy-bugs in greenhouses. The other 

 species are general feeders. 



If it were not for these industrious enemies of our fruit and vine 

 pests, California would be far from ranking i^o-day the chief fruit- 

 producing State of the Union. 



FIG. 100. Novius koebelei. 



Section HETEROMERA. 



This section is a rather miscellaneous lot of beetles, including several 

 small obscure families, as well as two large ones. All those beetles 

 which have the front and middle feet with five tarsal segments and 

 the hind feet with four are included in it. 



The family Tenebrionidse are the "darkling beetles." They are usu- 

 ally dark brown or black in color, oblong or oval in shape, have the 

 head more or less inserted in the prothorax, and, on account of their 

 long legs, are very awkward in their movements. Both adults and 

 larvae are scavengers, the latter much resembling wireworms in appear- 

 ance. The common pinch-bug, Eleodes sp., which when disturbed 

 stands on its head and emits an ill-smelling fluid, is a familiar type. 

 The meal-worm beetle (Tenebrio molitor), bred by bird fanciers for 

 food, and Tenebrio obscurus, found about stored grain products, are 

 cosmopolitan species. 



