376 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



These maggots are the offspring of small flies, somewhat 

 resembling small houseflies and very similar to those of the 

 cabbage root-maggot.* The wings expand about three-eighths 

 of an inch and the body is half that long. The male is gray with 

 black bristles and hairs, the face is white with black hairs, there 

 are three black lines between the wings, and the abdomen bears 

 a row of black spots along the middle. The female is a little 

 larger, inclined to dark yellowish, and with a yellowish face. 



Life History. The flies appear in the spring by the time 

 young onions are up and the eggs are deposited in the sheath 

 and in the axils of the leaves, from two to six being placed upon 

 a plant. The eggs are just perceptible to the eye, white, oval, 

 and about one-twenty-fifth of an inch long. The young maggot 

 works its way down from the sheath to the root, upon which it 

 feeds until it is consumed, only the outer skin remaining, and 

 often cuts off the plant completely. Another plant is then 

 attacked and often several young plants are consumed before 

 the maggot is full grown. Later in the season the maggots bore 

 into the bulbs, a number of maggots usually being found in a 

 single bulb and their presence being indicated by a slimy mass 

 of soil at the entrace of the cavity. If such bulbs are not killed 

 outright, they usually rot in storage. The first presence of the 

 pest is indicated by the wilting of the young plants, and by the 

 central leaves of the older plants yellowing and dying. 



The maggots become full grown about two weeks after hatch- 

 ing and are then about three-eighths of an inch long. They are 

 dull white, with the jaws appearing beneath the skin as a short 

 black stripe at the pointed end of the body. The posterior end 

 of the body is obtuse and is cut off obliquely, the margin of the 

 last segment bearing a number of tubercles by which this species 

 may be distinguished from the cabbage-root maggot. (See 

 Slingerland, I.e.) 



The outer skin of the maggot now becomes hardened and 

 within it the insect transforms to the pupa, which remains in the 

 soil at the base of the plant for about two weeks, when the adult 

 fly emerges. Two or three generations probably occur in the 

 Northern States. Professor R. H. Pettit states that some of the 



* See Slingerland, Bulletin 78, Cornell Agr. Exp. Sta., p. 495, for characters 

 distinguishing these two species. 



