Ri'RAL School Leaflet 



1069 



plant and crawl down into the head, where they injure and soil the tender 

 white leaves. 



This cabbage pest is best controlled by spraying the plants with one 

 of the arsenicals, paris green or arsenate of lead. There is no danger 

 in spraying cabbages with a poison up to the time when they are half 

 grown, and even later. The outside leaves never fold up about the head, 

 hence there is little danger of enclosing the poison within the cabbage. If 

 paris green is used, it should be applied in the proportion of one pound to 

 one hundred and fifty gallons of water, or sifted on dry, in the latter case 

 being thoroughly mixed with flour in the proportiDn of one jDOund to 

 twenty-five pounds of flour. 

 This should be applied in 

 the morning, when the dew is 

 yet on the cabbage leaves. 

 Arsenate of lead may be ap- 

 plied in the proportion of two 



and one-half pounds to fifty ' 4 



gallons of water. 



THE CABBAGE APHIS 



Appearance of the insect. — 

 The cabbage louse, or aphis, is a 

 small insect with an egg-shaped 

 body covered with a whitish 

 mealy substance. It has long 

 antenna; and sucking mouth- 

 parts in the form of a beak. 



Story of its life. — If late in the fall we were to examine carefully leaves 

 of cabbages that had been infested with this aphis, we should almost 

 surely find some of the dark brown eggs of this little pest. The 

 eggs seem to have a thick, heavy covering, and they remain on the old 

 cabbage leaves throughout the winter, exposed to all the vicissitudes of 

 the season. In the spring the eggs hatch, and the young lice find a living 

 for a time, at least, by sucking the juices from the tender leaves of the 

 sprouts sent out by the old stump. In about two weeks another genera- 

 tion of aphids is borne alive by the mother aphids, and in the course of 

 two or more weeks a third generation appears. This rate of increase 

 continues during the whole stimmer season ; for generation after generation 

 is produced as long as the food supply lasts and the weather is favorable. 

 Finally, late in the autumn the shining black eggs are again laid on the 

 leaves, thus completing a very interesting life history. 

 Injury and control. — The cabbage aphis, like all other aphids, has a 



Mother aphis luith colony of young aphids 



