INSECTS INJURIOUS TO POTATOES AND TOMATOES 271 



two other common forms are of a slate-black color. Very often 

 when these beetles congregate in numbers they are a great 

 nuisance, not only in the potato-patch, but upon many other 

 plants of the garden or truck-farm. 



Unfortunately, they present to the farmer a very peculiar 

 problem, for while the beetles are often exceedingly injurious, 

 the larvae are beneficial, eating large quantities of grasshoppers' 

 eggs 



Life History. The life of these insects is unique. The female 

 lays a large number of eggs in a small cavity in the earth, and 

 from these hatch some small, long-legged larvae, which run about 

 searching for the pod-like masses of grasshoppers' eggs, upon 

 which they feed. As soon as the appetite of one of these little 

 egg-hunters is appeased, he sheds his skin, and now being sur- 

 rounded by food and no longer needing his long legs for running, 

 in the next stage of his existence his legs become very short and 

 rudimentary, and he remains almost immobile while feeding upon 

 the rest of the eggs 



Control. Spraying with Paris green or arsenate of lead, as 

 advised for the Colorado potato-beetle will kill the beetles, and 

 where the vines have been regularly sprayed but little trouble 

 will be had with them Where they suddenly appear in large 

 swarms in gardens or on truck land, they are often destroyed by 

 a line of men and children slowly driving them with branches, as 

 the beetles move but slowly If a ditch is available it may be 

 oiled, and the beetles destroyed like grasshoppers, or they may 

 be driven into a windrow of straw, hay, or any inflammable rubbish 

 and burned in it. 



Three-lined Leaf -beetle * 



Closely related to the Colorado potato-beetle, and very 

 similar to it in habits, is the Three-lined Leaf-beetle. The eggs 

 may be distinguished by the fact that they are usually laid in 

 rows along the midrib on the under side of the leaf, while those 

 of the potato-beetle are laid indiscriminately in bunches. The 

 larvae, however, may be readily distinguished from all other 

 insects attacking the potato by being covered with a disgusting 

 mass of their own excrement. 



* Lema trilineata Oliv. Family ChrysomelidcB. 



