264 INSECTS INJURIOUS TO STAPLE CROPS. 



Flea-beetles. 



Several species of flea-beetles, chiefly Systena tcsniata, 

 Systena Mulsonias, Disonycha ti'iangularis, and Phyllotreta 

 vittata, often do considerable injury by gnawing small 

 holes in the npper and lower surfaces of the leaf, giving it 

 an appearance as if affected by leaf-sj^ot, or puncturing it 

 full of small holes, and thus stunting the growth of the 

 plant. 



The Yellow-black Flea-beetle (Diso7iycha xantliomelcena). 



This is one of the common beet-insects, both the larva 

 and adults feeding upon the leaves. It may be distin- 

 guislied among the Flea-beetles by its comparatively large 

 size (its length about a quarter of an inch), by its metallic 

 greenish-blue or black head and wing-covers, with the 

 thorax uniformly pale yellowish above and black beneath, 

 and the abdomen yellow beneath. 



A much smaller, also very abundant, species whose 

 injuries in spring frequently attract attention is the Pale- 

 striped Flea-beetle {Systena tmniata). This is about an 

 eighth of an inch in length, light yellowish brown in 

 general color, with a l)road, pale stripe down each wing- 

 cover. 



Most of the Flea-beetles are so similar in their general 

 habits that they may be treated together, and the same 

 remedies will be applicable for each species. The beetles 

 hibernate over winter in woodlands, under rubbish, etc., 

 and in the early spring deposit their eggs on the roots of 

 common weeds of the family Solo7iace(B, such as the James- 

 town weed, horse-nettle, etc. On these the larva? feed, 

 mining the roots and stems of the plants. When full- 



