348 Report of the Mycologist of the 



fested by it can be readily detected by the curling of the leaves. 

 On the under surfaces of the curled leaves the insect may be 

 found in immense numbers sucking the juice from the plant. It 

 is to be observed that the melon-louse generally works from the 

 edges of the field toward the center. The explanation is this: 

 The insect feeds upon quite a variety of weeds, such as the 

 dandelion, dock, shepherd's purse, plantain, etc., which are 

 abundant along the margins of cultivated fields. When the 

 cucumber plants appear the lice leave the weeds and go to feed 

 upon the cucumber leaves which are more to their liking, and 

 thus it is that they work from the edges of the fields to the 

 center. 



In the vicinity of Huntington some damage was done by the 

 boreal lady-bird beetle* which is a hard-shelled beetle, about 

 three-eighths of an inch long and nearly as wide, and very con- 

 vex. Its color is dirty yellow with black spots. Both the beetle 

 and its larva feed upon the cucumber leaves — ^the beetle from the 

 upper surface and the larva from the under surface. Their work 

 is conspicuous and readily recognized as insect work. 



A disease which did more damage that all the above named 

 insects is a mysterious wilt disease which is characterized as fol- 

 lows: At almost any time after the plants have commenced to 

 run they suddenly wilt without any apparent cause. In some 

 cases the whole plant wilts; in others a portion of the plant or, 

 perhaps, a single leaf, while the remainder remains healthy. 

 Healthy plants and diseased plants may be frequently found in 

 the same hill. A casual examination of plants recently wilted 

 reveals nothing which could cause the death of the plant and so 

 this disease is indeed a puzzle to the farmer. But in the later 

 stages of the disease a rotten spot may generally be found at the 

 base of a wilted leaf or somewhere on the main stem. Micro- 

 scopic examination shows that in the neighborhood of the rotten 

 spots the tissues are swarming with exceedingly minute germs 

 called bacteria, and these are the cause of the trouble. Dr. 

 Halsted, who has given considerable study to the wilt disease of 



*Epilachna borealis Fabr. 



