The Pea 



231 



nor is it a good plan to use seed in wliieh the weevils have 

 been killed, as such seed produces only weak plants. Seed 

 peas may be held over to the second year, by which time the 

 weevils will have emerged and died. 



Pea aphis {Macrosiphum pisi) . — A moderate sized pea-green 

 plant-louse that often attacks peas in great numbers, causing 

 the plants to take on a sickly yellowish appearance and die. 

 Infested blossoms are blasted and injured pods are stunted 

 and rendered worthless. The pea aphis passes the winter on 

 clover, in the South principally on crimson clover. Control: 

 Peas grown in rows about twenty inches apart are less likely 

 to be injured than when sown broadcast. When grown in 

 rows the lice may be controlled by spraying with " Black 

 Leaf 40 " 11 oz. in 100 gals, water in which 10 lbs. fishoil 

 soap have been dissolved. Applications should be made at 

 weekly intervals. Avoid loss by raising the main crop early 

 in the season for the cannery before the lice become abundant. 



Pea moth {Laspeijresia nigricana) . — A small slightly hairy 

 yellowish black-headed caterpillar about i/4 in. long, that in 

 the Northern States and Canada sometimes causes great dam- 

 age by infesting pea pods, where it feeds on the unripe seeds. 

 In Wisconsin the moths begin laying eggs about the middle 

 of July, which hatch in a week or ten days. Control: Both 

 very early and late varieties of peas are less liable to injury. 

 Adopt a crop rotation in which peas do not follow peas nor are 

 planted in fields adjourning those interested the previous year. 



We may distinguish three uses or purposes for which peas 

 are grown: as picked peas, the pods being gathered by 

 hand and the product sold directly in the market; as a 

 canning crop, whereby they are grown under much less 

 intensive methods, mown with a mowing-machine, trans- 

 ported by wagon-load or truck-load, and shelled by run- 

 ning vines and pods through machinery devised for the 

 purpose; as a general field crop, often in connection with 

 oats, for forage. 



