39 



THE CABBAGE CTJRCULIO. 

 (Ceulorhynchus rapa Gyll.) 



RECEXT OCCURRENCE AND INJURY. 



During June of 1897 Mr. B. R. Bones wrote to this Department con- 

 cerning damage to cabbage in the vicinity of Racine. Wis., and later, 

 June 20. sent specimens of the larva? of the insect concerned in the 

 injury, which proved to be of a species of Ceutorhynchus and the one 

 that has been known in American entomological literature until very 

 recently as C. rapm Gyll. 



Incidentally it might be remarked that our correspondent wrote 

 that the loss in his neighborhood during the fall of that year was over 

 2,000 tons of cabbage rotted in the field and in storehouses, this loss 

 being due probably to cabbage rot. which he believes is disseminated 

 by this insect. 



August. 9. 1898, Mr. Henry J. Gerling. St. Charles. Mo., wrote of 

 injury to the stems of kale, which is with little doubt due to this same 

 species. He was. however, unable to find specimens. The plant 

 begins to rot just below the leaves, and this follows the stem down to 

 the ground. There appears a small opening in the top part of the 

 stem, which grows from 2 to S feet high, and it is hollowed out some- 

 times far into the ground. 



During the first week of May. 1899, the beetles of this species were 

 observed in considerable numbers on the hedge mustard. SisyTnbrmm 

 officinale, an introduced European weed that grows almost everywhere 

 in meadows and in waste places in this country, and which is particu- 

 larly abundant in the vicinity of the Department of Agriculture. The 

 beetles were all observed singly at this time, preferably on plants of 

 advanced ao*e that were already in flower, and were usually hiding 

 beneath or near the buds and flowers. Later the species was observed 

 on turnip and horse-radish at Tennallytown, D. C as will be related 

 in detail in the account of the life history and habits of the species. 



June 26. 1899, Mr. Bones sent, by request, another lot of young 

 cabbage plants showing injury by what is now proved beyond doubt 

 to be this species, by finding the larvae in some of the affected stalks. 

 The plants were between 3 and 1 inches in height, and in many cases 

 the larger leaves were wilted. The stalks showed the punctures made 

 by the female in the deposition of her eggs, and in some cases a hole 

 had appeared just below the base of the leafstalk, through which the 

 larva, which was found within, was forcing its soft, brown castings. 

 Larvae were nearly mature at this time, and some few had evidently 

 already left the plants. The burrows are quite short where only a 

 single larva is present in the stalk, measuring only about 7 or 8 mm. 



