INJURIOUS INSECTS. 339 



house, and make the kitchen light. After getting the kitchen as 

 full of flies as possible, we blow a little of the pyrethrum into 

 the room, and in an hour have the pleasure of sweeping up the 

 flies and burning them in the stove. They all fall in a stupor to 

 the floor. Unless burned a few may recover. To breathe or 

 even to eat it is entirely harmless to man and the higher animals. 

 I have also used, the past season, kerosene to kill these insects. 

 It can be mixed with sour milk or with soft soap, as before 

 described. 



The evil from the cabbage butterfly is likely to be greatly 

 mitigated among us by a parasite, which also pupates in the pupa 

 skin of the butterfly. No pupa containing these should be de- 

 stroyed. Such chrysalids may be known by their darker color. 



The Radish Fly. Anthomyia raphani, Haw. Family, 

 Muscidce. Order, Diptera. 



NATURAL HISTORY. The small, ash-colored flies, very like the 

 onion fly (Fig. 16), doubtless hibernate, though some may pass 

 the winter as pupae. However this may be, the flies are around 

 early in the spring, for our earliest radishes are the ones most 

 liable to suffer from attacks. The eggs are laid on the stem 

 close to the ground. These soon hatch, and the whitish, footless, 

 conical larvae, very like the onion maggot (Fig. 16), feed on the 

 roots, forming grooves all over its surface, which induces decay, 

 and renders the roots unfit for use. In June they tranform to 

 pupae and to images, and are ready to make a new deposit of 

 eggs. Hence we see why our early radishes are so very liable 

 to attack, while later ones are often free from injury, though 

 some years none seem to escape. Whether there are more than 

 two broods a year, and whether they attack other plants than 

 radishes, are, so far as I know, still open questions. 



REMEDIES. The late Dr. Walsh recommended hot water as 

 fatal to these maggots and harmless to the plants. I have tried 

 this with some, though not satisfactory success. I have suc- 

 ceeded better by use of a carbolic acid mixture the same that 

 I would recommend to repel the peach borer moth and the 

 squash borer moth. I mix one quart of soft soap and one gallon 

 of water. Heat till the mixture boils, and then add one pint of 



