54 



FARMERS BULLETIN 856. 



seeds large enough for them to develop within. They differ from 

 the true pea weevil in that they produce several generations each 

 year on dry seed. 



Control. — Fumigate with carbon disulphid. (See Farmers' Bul- 

 letin 799.) 



PEA APHIS. 



The pea aphis (fig. 61) is one of the larger species of plant-lice, 

 measuring about three-sixteenths of an inch, with a total wing 

 expanse of about four-tenths of an inch. It is uniform pea green, 

 the same as its food plants. Attack begins on young vines, the " lice " 

 gathering in clusters about the terminals or tips. Later they attack 

 the stems and sap the life of the plant. 



Fig. 61. — The pea aphis (Macrosiphum pisi) : a. Winged female; b, same from side, with 

 wings folded in natural position, as when feeding ; c, wingless female ; d, nymph in 

 last stage. ^luch enlarged. 



Control. — Nicotine sulphate and kerosene-soap emulsion are good 

 remedies if applied when'the insect first begins attack early in the 

 spring. If peas are grown in rows Avide apart to permit a one 

 horse cultivator between them, the " lice " can be brushed off with 

 boughs of pine with the leaves on, following with the cultivator im 

 mediately afterwards to bury the pest. Pine boughs also may be 

 used by hand. Crop rotation is advisable. It appears that this insect 

 affects practically no other garden crop than peas. Alternate plants 

 are clover, alfalfa, field peas, and several leguminous weeds. 



Mildew of peas is indicated by a gray-white mold covering the 

 leaves and pods. Dust with sulphur or spray with Bordeauj 

 mixture. 



