60 INJURIOUS INSECTS OF KANSAS. 



Remedies. — When the worms appear in great numbers they are 

 often entirely swept away in a given region by the spread of a 

 contagious bacterial disease. Prof. S. A. Forbes has observed 

 the workings of this disease in Illinois. In the fall of 1883, he 

 found this disease to be raging among the cabbage-worms all over 

 Illinois, and declares it to be his opinion that there are good grounds 

 for belief that a means of successfully combatting the Cabbage- 

 worm will be found in artificially spreading this contagious dis- 

 ease. 



Searching for the eggs on the leaves and destroying them may 

 be resorted to with advantage. 



Pyrethum (see page 9) may be mixed with six to eight times 

 its bulk of flour and dusted on the cabbage with a powder gun. 

 This substance is not poisonous to human beings. It should be 

 applied about once a week as long as any worms remain. 



Dr. Riley advocates the use of hot water. He says: 



Every visible worm upon the cabbages may be killed by the use of 

 water at the temperature of 130° Fahrenheit. The water may be boil- 

 ing hot when put into the watering can, but it will not be too hot when 

 it reaches the cabbage leaves. 



Kansas Notes. — The Imported Cabbage-worm Butterfly is, as its 

 name indicates, not a native of North America. It was intro- 

 duced about 1856 or 1857, having been first taken at Quebec in 

 1859. In 1864 it had not extended more than forty miles from 

 Quebec as a center. In 1866 it was taken in the northern part 

 of New Hampshire and Vermont. It steadily spread north and 

 west over the United States, until in 1880 it was found abun- 

 dantly in eastern Kansas by Professor Snow. 



SOUTHERN CABBAGE-WORM. 



{Pieris profodice Boisd.; Order, Lepidoptera.) 



Diagnosis. — Infesting cabbage; a black-dotted, greenish-blue 

 caterpillar, with four longitudinal yellow stripes, feeding on the 

 leaves. 



Description and Life-history. — The adult is a butterfly of the 

 same genus as the Imported Cabbage-worm Butterfly {Pieris). 

 The black markings on the wings are more numerous and exten- 



