ENTOMOLOGY 165 



an inch long eats small holes all over the surface of the leaves and 

 causes much injury in this way; but a worse result is that the 

 spores of the fungous diseases called "Blight" find a suitable place 

 in these holes for germination and the complete destruction of the 

 leaf soon follows. Flea-beetles as a class have already been referred 

 to ; it is unnecessary, therefore, to do more than state that spraying 

 with Bordeaux mixture is a satisfactory remedy for both the insect 

 and the blight. 



Blister Beetles are often reported as appearing suddenly in 

 great swarms in the potato fields and greedily devouring the foliage. 

 An account of them has already been given under insects attacking 

 Beets and Spinach. 



Potato Stalk-Borer is an occasional cause of injury to the plant 

 in this country, but in some of the States to the west and south it 

 is considered almost as great a pest as the Colorado beetle. As the 

 name indicates, the attack is made by boring the stalk ; this is done 

 by the grubs, which are whitish in color and without legs. The 

 small beetles, about a quarter of an inch long, are ashen-gray in 

 color and belong to the family of weevils or snout beetles, having 

 the head developed into a long beak; the base of the wing-covers is 

 marked with three distinct black spots, which readily distinguish 

 it from similar species. About the month of June the parent makes 

 a hole in the stalk of the potato with its snout and deposits an egg 

 and repeats the operation a number of times. The grubs which 

 hatch from them burrow up and down in the stalks, devouring the 

 interior, and when full-grown, about the beginning of September, 

 form their cocoons inside the stalk near the base of the plant; the 

 beetles emerge later on, but remain in this retreat all winter. 



No application of poison is of any avail, as the grubs are out 

 of reach in the stalk, but much may be done to exterminate the 

 insect by cleaning up and burning all the remains of the plants 

 after the potatoes are dug in the fall ; this is advisable also in order 

 to destroy the germs of fungous diseases. 



RADISH. 



Radishes are very liable to attack and serious injury when they 

 first come up in the seed beds by the minute Flea-beetles described 

 among the insects that are general feeders; cheese-cloth screens are 

 found to be the best protection. The Radish-maggot is the same or 

 a very closely allied species to that which attacks the roots of cab- 

 bages, and may be treated in much the same way; protection with 

 cheese-cloth is >by far the simplest and entirely effective method of 

 securing perfect radishes in the spring. 



INSECTS AFFECTING RHUBARB. 



Rhubarb Snout-Beetle. Rhubarb is usually free from insect 

 pests, there is, however, a long, slender snout-beetle, which is to be 

 found early in the spring and late in the fall, resting on the plants. 

 It is dark grey in color and covered with a rust-colored powder that 

 nibs off easily. This beetle is the parent of the white, grub-like 

 borer that tunnels in the leaf and flowerstalks, and the eggs of whit-h 

 are laid in small cavities cut in the tissue of the plant. It is said 



