320 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



surface of the ground. The maggots, hatching, work their way down- 

 wards and feed upon the root, sometimes simply grooving the bark, but 

 more often boring into the interior. Frequently they are so numerous 

 that many of the young plants are killed outright; again, however, they 

 simply check the growth and cause the malformation of the root, known 

 as 44 club root," when the leaves take on a yellowish hue and the plant 

 wilts at noonday. Curtis says: u 0n pulling up the stalks of some cab- 

 bages recently cut, 1 found the roots enlarged, lumpy, and carious, and, 

 on opening them, they were hollow, with the maggots of the Cabbage- 

 Fly, full-grown, in cavities*" Of course by far the greatest damage is done 

 to the young plants, which are less able to stand the constant drain upon 

 their vitality. The work of these maggots upon turnips is well described 

 by Fitch, as follows: 



"These maggots infest the turnip and rutabaga also, mining an 

 irregular burrow in the interior, or inhabiting eroded spots upon their 

 outer surface. Sometimes a small roughened spot is seen, appearing 

 like a crack in the skin of the turnip, with its edges rough and ragged 

 and turned outward, and on paring off this roughened spot a plump 

 white maggot is come upon, lying in a cavity it has made there for 

 itself. At other times a large, eroded spot occurs, which is filled with 

 wet and slimy dirt. On removing this dirt the surface is found to be 

 rough and warty, with little grooves here and there, in each of which is 

 a maggot. Sometimes, also, a maggot is seen with only its anterior 

 end imbedded in the turnip, leaving a third or half the length of its 

 body projecting out therefrom." 



The number of broods in the course of a season has not been accu- 

 rately followed in any given latitude, but there are at least three, and 

 the insect hibernates both in the larva state in the roots and in the 

 puparium state underground. According to Curtis, the adult flies also, 

 doubtless, hibernate in cracks and crerices. Taschenberg states that 

 there are annually three generations in Germany, and that both the 

 flies and pupae hibernate. Our first acquaintance with this insect was 

 in June, 1867, when Prof. A. X. Prentiss, then at the State Agricult- 

 ural College, Lansing, Mich., sent us specimens of the larvae, with an 

 account of their gnawing and excoriating both the stems and roots of 

 cabbages, and thereby doing much damage. They transformed June 

 21-35, just below the surface of the ground, to puparia (Plate VIII, Fig. 

 4, b) of a honey -yellow color, some lighter, some darker, and the first 

 flies issued June 29 onward. We have since (in 1878) found the species 

 not only working in the normal way in the roots, but also burrowing in 

 the stout midribs of the leaves. From June 8-13 quite a number of 

 the perfect flies were obtained. 



NATURAL ENEMIES. 



80110116 has reared the parasitic Alysia manducator Panzer from the 

 larvae of several Anthomyians, but, so far as we are aware, no similar 

 parasites have been reared from the species in this country. The Sta- 

 ph ylinid beetle — Aleochara anthomyicc — has been bred by Mr. P. S. 

 Sprague, at Boston, from the puparium of A. brassiccc and published by 

 him as a true parasite (American Entomologist, Vol. II, pp. 302, 370). 

 aIofc recently Dr. W. S. Barnard (ibid., Vol. Ill, p. 99) has given an in- 

 teresting account of the occurrence of this species at Ithaca, N". Y., but 

 he gives no evidence of other than predaceous habits on the part of the 

 adults. 



