742 ANNUAL REPORT OF THE Off. Doc. 



potato crop bj the flea beetle. It is unnoticed by some growers 

 while at work, although the effect is soon observed in a loss of dark 

 color in the foliage and an appearance of unthriftiness. It is the 

 insect that punctures the leaves, gnawing innumerable holes through 

 them. Several species attack the potato, the so-called ^'cucumber 

 flea beetle.'^ {Ilaltica cucu7neris) being most observed in the north. 

 This insect is minute, and easily escapes detection by those unac- 

 quainted with its work and habits. Usually it attacks potatoes at 

 a critical period of growth, and a close observer will soon discover 

 the very small holes or yellow spots in the foliage indicating its 

 presence. Many insecticides have been used with little success,and 

 it remained for the Vermont Station to call public attention to the 

 merit of Bordeaux mixture as a repellant. To this, Paris green 

 should be added at the rate of six ounces to a barrel of the mixture, 

 and the spraying must be most thorough. Arsenites alone are not 

 effective, and the spraying with Bordeaux mixture and an arsenite 

 will not give the desired results unless it is very thorough and per- 

 sistent. Probably no other one enemy does as much to weaken the 

 vitality and lower the yield of potato plants as these minute jumping 

 beetles, and spraying against their attacks is urged even when the 

 s-praying is not needed to prevent blight or the Colorado beetle. 



Where a grower has a very small acreage and has no equipment of 

 sprayers, he may have partial success in repelling the flea beetle by 

 dusting the vines with lime or tobacco dust when they are wet with 

 dew. 



A Cause of Pimply Potatoes. — In this place attention is called to 

 a pimply condition of the potato that sometimes makes it very un 

 desirable in market. The Station at Geneva has done good work 

 in investigation of this trouble, and in Bulletin No. 113 it summarizes 

 its results as follows: "The cause of the trouble known as ^pimply' 

 potatoes has been definitely determined. Minute, slender white 

 grubs have been found boring into the tubers, roots and root-stock of 

 the potato during the growing season. The pupae of these grubs 

 have been found in connection with them. The grubs and the pupae 

 have been proven to be the early stages of the common cucumber 

 flea beetle, a very iojurious insect, the life history of which has here- 

 tofore been imperfectly known. The wound made by the boring of 

 the grub results in the formation of a 'sliver,' but a pimple may or 

 may not be produced, depending, probably, upon the state of growth 

 of the tuber at the time the wound is made. The most practical 

 method of preventing the pimply potato trouble is to protect the 

 foliage against the attacks of flea beetles by thorough spraying 

 with the Bordeaux mixture." Additional reason is thus afforded 

 for fighting the flea beetle. 



The Blister Beetle. — The ''old-fashioned potato bug" is an old ac- 



