2 BULLETIN 843, IT. S. DEPARTMENT OF AGRICULTURE. 



so far as is known, are practically confined to beans, and no variety 

 seems to be exempt from injurious attack. This insect has been ob- 

 served feeding on various forms of the kidney bean (Phaseolus vul- 

 garis et al.), including string, pole, navy, and tepary or Mexican, 

 and on the lima bean (Ph. Iwiatus). Of these string beans are 

 favorites. On one occasion the soy bean (Soja hispida) was at- 

 tacked. The beetles, unlike those of the bean leaf -beetle (Gerotoma 

 trifurcata Forst.), show no tendency to injure very young plants and 

 the larvae work on the lower surface of the leaves, skeletonizing large, 

 irregular areas without cutting the epidermis or upper skin. (PL 

 II, III.) 



It is fortunate that its field of operations is limited, both as re- 

 gards the crop plants affected and the territory over which it ranges. 

 It has been estimated that it does an annual damage in New Mexico 

 varying from 5 to 100 per cent of the crop, the average loss being 

 conservatively placed at 10 per cent. 



This species is remarkable in that it is one of two species of lady- 

 birds occurring in the United States 1 which feed exclusively on 

 vegetation, the other forms of the ladybird family being predacious 

 and subsisting largely on plant-lice, or aphids. and the eggs of 

 insects. 



SYNONYMY. 



The bean ladybird was described by Mulsant in 1850 (1, p. 815 ) 2 

 under the name by which it is known in economic literature, Epi- 

 lachna corrupt a. In the original description in which this name 

 appears, printed under No. 90, E. varivestis is also described as No. 

 91, yet Crotch (3, p. 62), followed by Gorham (8, p. 242), recognized 

 the latter as the proper name for the species, and relegated corrupta 

 to synonymy, in which case the strict law of priority has not been 

 followed. This species has evidently been described under at least 

 a half dozen names, but as there is no means of deciding positively 

 the exact term to apply to the species under consideration, Epilachna 

 corrupta is here used to avoid further confusion, although E. varipes 

 Muls. was described first and is acknowledged by Crotch and 

 Gorham to be the same species. The name used by Bland (2), E. 

 maculiventris, described in 1864 from the Rocky Mountain region of 

 Colorado, undoubtedly applies to this species and naturally falls 

 into synonymy. 



DESCRIPTION. 



THE ADULT. 



The adult (fig. 1, b) is a robust beetle, oval in outline, and about 

 one-fourth of an inch in length by about one-fifth of an inch in 



1 The other is known as the squash ladybird (Epilachna borealis Fab.). 



2 Reference is made by figures in parentheses to " Literature cited," p. 20. 



