128 MASSACHUSETTS HORTICULTURAL SOCIETY. 



the skin in thick sticky drops that harden much like the gum from 

 wounds on cherry trees. The diseased fruit, if small, shrivels and 

 ceases to grow. In more mature fruits the bacteria work their 

 way throughout the tissues even into the seeds. 



The disease is carried from plant to plant chiefly by the striped 

 cucumber beetle that is often so destructive to the seedling cucum- 

 bers. The large squash bugs are also agents of dissemination. 

 These insects gnaw or suck at diseased leaves or fruits and then fly 

 to healthy leaves where they introduce the bacteria, sticking to 

 their mouth parts, into the wounds which they make in the healthy 

 tissues. It is these cucumber beetles that, finding their way into 

 the greenhouses in the autumn, carry the bacteria with them and 

 infect the crop there. I observed in one house that the bees used 

 for pollinating carried the infection from flower to flower. Almost 

 every fruit was infected while yet quite small. Aphids which were 

 present in another house seemed to be the chief agents in scattering 

 the disease. 



Just how the bacteria are carried over winter is I believe not 

 certainly known. The beetles that are responsible for their dissem- 

 ination during the summer hibernate through the winter and it 

 seems possible that they may harbor the bacteria and thus tide 

 the organism over from one season to the next. Since it has been 

 observed that the bacteria get into the seed it is possible that in 

 this way the bacteria are carried over winter in a more or less dor- 

 mant condition. This would not be strange as it is known that 

 bean l)light is regularly carried over in the seed. 



The methods of combating this disease must be entirely pre- 

 ventive. First, keep the crop as free as possible from bugs and 

 beetles. For methods of doing this I must refer you to the ento- 

 mologist; I know of no way that is entirely satisfactory. Second, 

 remove every wilted leaf and vine as soon as it appears and 

 destroy it. I have found it a successful practice in controlling 

 the disease in my own garden to go through the patch every other 

 morning very early and remove every wilted leaf, crushing it quickly 

 in my hand thus killing the beetle that is almost invariably to be 

 found underneath the leaf. I thus get rid of a large number of 

 the most dangerous insects — the contaminated ones. Third, 

 plant clean seed. Be sure the seed is from perfectly healthy fruits. 



