THE STRIPED FLEA-BEETLE 235 



actually strike each aphid in order to destroy it. Wild mustard 

 and shepherd's purse in the field should be destroyed. Young 

 plants in the seed bed are often infested before transplanting; 

 hence the necessity, as in the case of the cabbage maggot, for 

 screening the cold frames with fine screens or cheesecloth. Young 

 plants, if infested, may be dipped at their tips in a weak solution 

 of soap in order to destroy the lice upon the leaves. If spraying 

 is resorted to, nicotine sulfate may be used at the rate of one part 

 of the extract to sixty-four parts of water. Or use whale-oil soap 

 at the rate of one pound to six gallons of water. Or use any laundry 

 soap at the rate of one pound to three gallons of water. These 

 lice, like other species, are subject to extensive attacks by parasites. 



The Harlequin Cabbage Bug (Murgantia histrionica Hahn). 

 This is a shiny black or deep blue insect with brilliant red or 

 orange markings. It is about one-half inch long and is more or 

 less flattened. It is sometimes called " terrapin bug" on account 

 of its shape and markings. The young bugs resemble the older 

 ones closely, but have no wings (Fig. 244) . These bugs will prob- 

 ably never be very injurious in the northern tier of states, since 

 they are particularly a southern pest. 



Life History. They feed on any of the mustard family of 

 plants, but prefer cabbage. The adults live over winter in old 

 cabbage stumps and in weeds and rubbish left on the field, and 

 emerge in the spring. Eggs are laid on kale or wild mustard or 

 other wild plants of the mustard family to which cabbage, radishes, 

 and turnips belong. There are three or more broods. 



Control. When once established, they are difficult to combat. 

 Old stalks and leaves should be cleared up to remove from the 

 field hibernating quarters. A few piles of brush may be left to 

 attract the adults in the fall that they may be destroyed. A trap 

 crop of kale or mustard may be planted early in rows through the 

 field that is intended for cabbage. The bugs prefer kale to cabbage, 

 and these trap rows can be sprayed when covered with bugs, 

 using pure kerosene. The nymphs or young bugs may be killed 

 with a whale-oil soap solution. Use one and one-half or two pounds 

 of soap to a gallon of water; or use one part stock solution of kero- 

 sene emulsion in six parts of water. Sprays, however, are not to 

 be depended upon in this connection. The importance of killing 

 the hibernating brood cannot be too strongly emphasized. 



The Striped Flea-beetle (Phyllotreta vittata Fab.). This is 

 a striking insect, one-tenth of an inch long or less. It is black, 



