316 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



few days sheds its outer skin containing the spines and changes to 

 the pupa state (Fig. 229, B). From these pupa the beetles appear 

 a few days later. They live over winter, and appear about as 

 soon as the beans arc up in the garden or field and begin to feed 

 upon the leaves, on the under side of which they deposit their 

 yellowish-brown eggs in large clusters after the manner of the 

 ' Colorado potato beetle.' 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. 229, /). 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 would probably 

 obviate this. 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 probably 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 107, 301.) 



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 



* Macrobasis unicolor Kby. 



