174 



AN ECONOMIC ENTOMOLOGY. 



laid by the beetles are often seen in abundance on infested 

 plants. 



The species of Mcgilla and Jlippodamia are more oval and 

 less convex than usual, and some of them have been found feed- 

 ing on pollen or even seeds, when their natural prey was scarce ; 

 yet I have observed these same species doing yeoman's work in 

 the destruction of plant-lice on melon-vines. 



The genera Adalia and Coccinclla contain the more hemispher- 

 ical types, and among the most common are the " 9-spotted lady- 

 bird," Coccinella g-?iotata, which is one of the larger species, and 

 the " 2-spotted lady-bird," Adalia bipuncta, which is the smaller 

 and perhaps most frequently seen in gardens and even houses. 

 Among the largest of our forms is the " 15-spotted lady-bird," 

 Ayiatis i§-punctata, interesting from its color variations, ranging 

 from creamy- white with distinct black spots to uniform mahogany 

 brown. 



Opening quite a distinct series of species, which are black, 

 with red or yellow spots, is the "twice-stabbed" lady-bird, Chilo- 

 corus bivulnerus, in which the larva is spiny. This is black, 

 almost hemispherical, with a somewhat ovate red spot on each 

 wing-cover, and is found throughout the United States. Its 

 chief food, in the larval as well as the adult stage, consists of scale 

 insects, and it is one of the most effective checks on that kind of 

 plant pe.st, under favorable circumstances ridding individual trees 

 completely. 



We have other similar but smaller species, sometimes with 

 numerous yellow spots on the wing-covers, and most of them 

 have the scale-eating habit to a greater or less extent. The 

 species of Pentilia are uniformly black and very small, less in 

 size than most of the scale insects upon which they prey ; but 

 they, as well as their minute spiny larvae, are great feeders, espe- 

 cially upon the eggs and larvae. The destructive San Jos6 scale 

 has no more persistent or effective enemy than this kind of small 

 lady-bird. 



The species of Scymmis are also small, usually recognizable by 

 their fine pubescent or hairy clothing and black colors. There 

 is a tendency to red-tipped wing-covers or red thorax, and these 

 forms also prey largely upon scales. To this family belong the 

 Australian species of Vedalia, Orcus, and Rhizobius, introduced 



