INSECTS AND DISEASES 79 



seen that some of the most destructive species pass 

 the early and late seasons in feeding on weeds or 

 other plants. Destroy these by clean cultivation. 

 Then the most of them pass the winter under vari- 

 ous kinds of rubbish. Clean up and burn all har- 

 boring material of that kind, and so destroy their 

 winter quarters. Then, too, if melon growers would 

 practice a regular three or four-year rotation of 

 crops, much of this insect trouble could be avoided. 



DISEASES 



Bacterial ' Wilt (Bacillus tracheiphilus, Smith) . 

 There is probably no disease attacking the cucurbi- 

 taceous plants which has spread over so wide a ter- 

 ritory in the last few years and which has so baf- 

 fled the scientists in their efforts to find a means 

 for its control as this. It was discovered in 1893 by 

 Dr. Erwin F. Smith of the department of agricul- 

 ture, attacking cucumbers and muskmelons, and 

 since that time much thought and labor have been 

 expended in trying to find a practical remedy or 

 means of preventing the disease. Up to the present 

 time, however, it may be classed with the pear 

 blight in this respect. Dr. Smith has proved very 

 conclusively, however, that the disease is due to a 

 specific bacterial organism, and that it is conveyed 

 from diseased to healthy plants by means of the 

 striped cucumber beetle (Diabrotica vittata), and he 

 is also of the opinion that it is communicated by the 

 squash bug (Anasa tristis). 



The disease may make its appearance at almost 

 any time during the summer and spread more or less 

 rapidly as favorable or unfavorable conditions seem 



