146 LEAF-BEETLES. 



THE PLUM LEAF-BEETLE. 



*(Nodo)iota tristis Ol.). 



This oval beetle is of a shining, dark, metallic-blue, 

 with legs and feelers yellow or chestnut brown; some spec- 

 imens are bronzed, purplish, greenish, or even very dark brown. 

 The thorax is densely punctuated with small dots. The dam- 

 age they cause is not very great, although in the South they cause 

 considerable injury by eating holes into die leaves of young plum 

 trees; the peach and apple foliage is also to their taste, as well 

 as that of the cherry, shad-berry, and choke-cherry, and Prof. 

 Ashmead reports that they "gnaw little irregular holes into the 

 blossoms and epidermis of the bolls of cotton, exposing them to 

 the weather, and causing them to drop." 



The beetles are not uncommon in Minnesota, especially up- 

 on apple trees, but they are not frequently seen, as they have 

 tbe habit of hiding themselves in the folds of the leaves. The 

 eggs are known, but not so the larvse, which, very likely, possess 

 the habits of related insects, i. e., are found among the roots. 



A very similar beetle, (Fig. 149), the Rose Leaf-beetle, (No- 

 donota puncticollis Say), is also found upon the same kinds of 

 plants, but seems to prefer the wild rose and blackberry ; it also 

 occurs on the young terminal leaves of willows, hence seems to be 

 a general feeder. If at all numerous these beetles can be poisoned 

 by means of the arsenites, and as they do not try to escape by 

 flight they can be captured in large numbers by inverted um- 

 brellas. 



There are still other and similar small beetles which are more 

 or less destructive to our fruit-producing plants, but none cause 

 very serious losses, and then only at long intervals, when their 

 number is increased by especially favorable climatic or other con- 

 ditions. 



Among the more typical leaf-beetles we have such forms as 

 the well known Colorado potato-beetle, (DorypJiora 10-lineata 

 Say), originally a native of the Rocky Mountains, feeding in its 

 old home on the sand-burr, (Solatium rostratum), a plant related 



