PEA AND BEAN INSECTS 87 



The Lima Bean Vine-Borer 

 MonopHlota nuhilella Hulst 



From INIar viand to Florida and x4.1abama, pole varieties of 

 lima beans are occasionally infested by a caterpillar that bur- 

 rows in the stalk, causing a gall-like enlargement which is about 

 1-J inches in length by ^ inch in diameter. These galls may 

 occur at any point from the surface of the ground to near the 

 tip of the vine. The injury inflicted varies with the position 

 of the gall and with the thriftiness of the vine. When the 

 caterpillar enters a well-formed stalk, the plant is not seriously 

 affected, but when the gall is formed in small stalks near the 

 tip, the terminal portion often wilts and dies or at least is not 

 able to produce full-sized pods. The full-grown caterpillar is 

 about I inch in length and of an unusual color for a borer, 

 being a beautiful blue-green, tinged with pinkish above. When 

 mature, it leaves the gall and pupates on or in the ground in 

 an oval silken cocoon covered with particles of dirt. The pupa 

 is dull olive-brown and a little less than i inch in length. Some 

 of the moths may emerge the same summer and lay eggs for a 

 second brood. The moth has an expanse of about | inch. 

 The front wings are brownish gray shaded with whitish especially 

 toward the base near the front margin and are marked with 

 several' small blackish streaks about one third the distance 

 from the base of the wing. The hind wing is translucent white 

 in the male and dark in female. 



No better treatment is known than to kill the caterpillars 

 with a knife while still in their burrows. 



Reference 

 U. S. Div. Ent. Bull. 23, pp. 9-17. 1900. 



Other Pea and Bean Insects 



Corn ear-worm : 211 

 Southern corn root-worm : 222 



