INSECT PESTS AND THEIR CONTROL 987 



The Imported Cabbage Web Worm (Hellula undalis, Fab.). — This 

 worm feeds upon cabbage, turnips and other similar crops, spinning a web 

 under which it retires when not feeding. 



Treatment. — Same as for cabbage looper. 

 Ent. Bull. 23, p. 54. 



The Imported Cabbage Worm {Pontia rupee, Linn.). — Of all the insects 

 on cabbage, this is the 

 worst pest. It is the larvae 

 of the white butterfly 

 seen fluttering about over 

 fields of cabbage during 

 spring and summer. 



Treatment. — Same as 

 for cabbage looper. 

 Bur. Ent. Cir. 60. 



The Melon Aphis 

 (Aphis gossypii, Glov.). — 

 This plant louse feeds not 

 only on melons but on 

 cotton, strawberries and a 

 number of other plants. 



Treatment. — Before 

 the leaves are badly curled 

 spray them with nicotine 

 solution, turning the vines 

 over if necessary, so as to 

 hit the under sides of the 

 leaves. In .small gardens Imported Cabbage Worm 



fumigate under tub with {Pontia ra V ce). 1 



carbon bisulphide, using A— Female butterfly. B— Above, egg as seen from 



about a teaspoonful to above; below, egg as seen from side. C — Larva in 

 each cubic foot of space. natural position on cabbage leaf. D— Suspended 

 _ , „ , chrysalis. A, C, D — Are slight! v enlarged. B — More 



lobaccorumes may also enlarged. 



be used. 



Bur. Ent. Cir. 80. 



The Potato Tuber Moth (Phthorimcea operculella, Zell.). — Potato 

 growing is now menaced in California, Washington and southern Texas 

 by this insect, which bores into the vines and tubers of potatoes. It also 

 feeds upon tomato, eggplant and tobacco, and on the latter plant is 

 known as the split worm. 



Treatment. — No satisfactory method of treatment is known, but the 

 injury may be partly prevented by clean methods of cultivation, crop 

 rotation and fumigation of infested tubers. The latter is by far the best 

 remedy. For a full discussion of methods of control see Farm. Bull. 557. 



iBiir. Ent. Cir. 60. 



