288 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



on the under side of which they deposit their 3^ellowish-brown 

 eggs in large clusters after the manner of the 'Colorado potato 

 beetle. 7 The spiny little larvae that hatch from these eggs 

 remain on the under side of the leaves, which they skeletonize in 

 feeding. The beetles eat through the veins of the leaves and do 

 not skeletonize them. They also eat into and destroy the green 

 pods as shown in Fig. 246, D. There is also one brood of this 

 insect in a season. 



Control. Paris green dusted upon the plants diluted with 

 100 parts of air-slaked lime or flour is recommended, or it may be 

 applied with Bordeaux mixture, 1 pound to 200 gallons, but much 

 care must be used not to burn the foliage, which seems to be very 

 susceptible to the arsenic. Arsenate of lead applied as a dust, 

 with or without a carrier, or as a spray at from three to five pounds 

 paste to 100 gallons of water is much more safe and is now more 

 generally used for that reason. In spraying, an underspray 

 nozzle must be used to reach under the leaves. Dilute kerosene 

 emulsion will kill the larvae, but must also be used with caution 

 to avoid injury to the plant. Whaleoil soap might be as effective 

 and less injurious to the plant. Upon small gardens handpicking 

 of the adult beetles as soon as they appear in the spring will prob- 

 ably be the surest means of combating them. Cleaning up the 

 old patch and plowing it under will doubtless aid in preventing 

 successful hibernation. 



Blister-beetles 



Several species of elongate, grayish, black or bright green 

 blister-beetles feed in large numbers upon bean foliage. The 

 general life history, habits, and remedies have been already 

 described. (See pages 104, 270.) 



The Ash-gray Blister-beetle.* This is the most common species 

 affecting beans in the East and westward to Kansas and Nebraska. 

 The beetle is a uniform ash-gray color and of the form shown in 

 Fig. 247. The beetles attack this and other legumes in immense 

 swarms, riddling the foliage in a few days if not checked, and 

 appear from the middle of June to the middle of July. 



Nuttall's Blister-beetle.^ This species occurs from the Mis- 

 issippi west to the Rockies, through the region of the Missouri 



* Macrobasis unicolor Kby. 

 t Cantharis nuttalli Say. 



