358 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



it. Most of these are importations from Europe, one of the 

 most important being a small wasp-like Braconid fly (Apanteles 

 glomeratus Linn.) which was purposely imported from England 

 in 18cS3. During the autumn of 1904 Dr. Chittenden states that 

 it killed practically every worm at Washington, D. C. The maggots 

 of these little parasites live within the worms and when full grown 

 come forth and spin masses of small white cocoons on the foliage, 

 often attached to the dead or dying worm (Fig. 167). Another 

 very important parasite is a minute Chalcis-fly (Pteromalus 



FIG. 258. Apanteles glomeratus, a parasite of the cabbage worm: a, adult 

 fly; b, cocoon; c, flies escaping from cocoons natural size, a, b, highly 

 magnified. (After Chittenden, U. S. Dept. Agr.) 



puparum Linn.), about one-sixteenth of an inch long, which was 

 probably imported with its host. These often emerge in immense 

 numbers, hundreds of them often being secured from a single 

 worm. Wasps frequently prey on the caterpillars, using them for 

 provisioning their nests. Various predaceous bugs also attack 

 the worms as well as numerous other internal parasites. 



Control. As the chrysalids pass the winter on the old stumps, 

 foliage, and rubbish on the field, it is evident that they should be 

 destroyed and the field plowed as soon after the crop is removed 

 as possible. A few stalks may well be left standing here and 



