15 



down without injury. Under ordinary circumstances, however, there 

 is no necessity for a change of residence and there is no evidence that 

 such change was voluntarily made during the season just passed. 



July 25 and afterwards other visits were paid the infested bean patch, 

 and by looking closely for fresh droppings upon the leaves, for gall- 

 like swellings and dying and wilting leaves, a considerable number of 

 the borers were secured that had escaped the first visit. When a well- 

 formed gall results from borer attack it sometimes happens, particu- 

 larly if the plant be well advanced in growth and the point of attack 

 be low down upon the vine, that the plant does not appear to be in 

 any great degree incommoded by the insect's presence, but it fre- 

 quently happens on the other hand that the gall, if badly formed or 

 made at a point where the plant is w'eak or weakly attached to the 

 pole, becomes in time so broken open that the upper portion is killed. 

 Several vines were thus found broken 1 and 5 feet from the ends. In 

 one case a plant was observed that had lost three branching vines, all 

 about 1 feet long and all bearing undeveloped pods. 



From careful observations of all infested vines it was found that 

 attack may take place at any point from the base of the vine on a level 

 with the ground to within a few inches of the tip; that the result of 

 attack A'aries greatly, a strong, well-grown plant being able to survive, 

 while a weak one usually suffers in greater or less degree. As is so 

 often the case with insect attacks, injury was much more noticeable 

 at one end of the rows, the northern in this instance, than elsewhere, 

 the southern end suffering somewhat less and the main portion of the 

 planting still less. Attack had begun at the north end in the direction 

 of the previous year's vines and ended at the southern or far extremity, 

 since the larvas matured much earlier in the vines at the former place 

 than in the latter. One stunted plant attracted attention August 5. 

 It was still green, but the leaves had all fallen away and there were no 

 pods. It had been attacked two inches above the ground, and although 

 the stem had not been severed, the plant had been practically a failure 

 in consequence of the injury. 



A few of the larvae that were taken from the oldest parts of the 

 largest vines were nearly full grown July 27, and by the beginning of 

 the second week of August all but a few were mature, and some had 

 escaped from the vines. 



A mature larva was seen to leave its gall July 29, in the morning at 

 about 11 o'clock. When the jar was next examined, at 2 o'clock the 

 same afternoon, the larva had disappeared in the earth, and the fol- 

 lowing morning its cocoon was found attached to the stem in which it 

 had lived, at the base, at the bottom of the jar. 



Examination of the jar in which the other larvae were confined 

 showed that some had reached maturhrv and entered the earth a few 

 days afterwards. One, however, was found August 1 which had just 



