The Cabbage Root Maggot. 491 



toothed,* thus making 14 fleshy points in all (Fig. 2, a). The tubercle on 

 the margin just above these bifid ones is equally as long but narrower. The 

 other tubercles are comparatively small, and the four lateral ones, two on each 

 side, are a little below the margin. On the venter, a little cephalad of the 

 bifid tubercles and just caudad of the vent, are two more fleshy pointed 

 tubercles projecting caudo-ventrad. The number, size, and arrangement of 

 these tubercles about the caudal end of the maggot (Fig. 2, a) have been 

 given in detail, for our observations lead us to believe that they, especially 

 the four larger more ventral ones, offer specific characters by which the Cab- 

 bage Maggot may be easily recognized and separated from the other common 

 Anthomyiian maggots. 



In short, the full grown cabbage maggot is about .32 of an inch 

 (8 mm.) in length, white, cj^lindrical, tapering cephalad and ob- 

 liquely truncate caudad with 12 fleshy tubercles around the cau- 

 dal margin, the lower two of which are two-toothed ; and the 

 cephalic spiracles have 12 divisions. 



The puparium. — This is the name applied to the case within 

 which the maggot passes through a wonderful transformation 

 which results in the perfect insect. This puparium is really the 

 skin of the maggot which has hardened and separated from the 

 creature within, which is then called the pupa ; thus the maggot 

 uses its own skin as a home to protect it while it changes to a 

 tender pupa and thence to the perfect insect. 



Many gardeners have doubtless seen these puparia, but did not 

 realize that they were an important stage in the life of this pest. 

 They can easily be found in the soil about badly infested plants in 

 June. As shown in figure 3, the puparium 

 is elliptical ovate in form, and being simply 

 the dried skin of the maggot, it naturally 

 shows the same fleshy tubercles at the cau- 

 dal end, usually less distinctly but sufficient- pm. z-— The puparium dor- 

 ly distinct for 'the specific determination of ^"'"''"' '"'"'' "''^''^"'■ 

 the insect. It varies from a light to a dark brown in color, de- 

 pending on its age, whether a few hours or several days old. It 

 is shorter than the maggot, measuring only about .2 of an inch 

 (5 mm.) in length; there is considerable variation in size, some 

 being fully one- third smaller than others. 



* Dr. Fitch says this is not true of the smaller young larvae. I have not examined speci- 

 mens less than one-half grown, but it holds true for all I have seen. 



