46 



In 1892 the cabbage curculio was again reported injurious in Mis- 

 souri by Miss Murtfeldt (Bui. 30, p. 50), when it was the occasion of 

 "much loss and annoyance to market gardeners in some parts of the 

 State by boring into the crown and roots of young cabbage and cauli- 

 flower plants, in many cases destroying 25 per cent of the plants in 

 the hot beds and just after they are set out." 



It was noticed at this time that the insects did not trouble the plants 

 after the head began to form. From experiments conducted that year 

 this writer became convinced that the insect returns to its original 

 food plant, wild peppergrass, from the stems of which young larvae 

 were obtained in July. 



In 1895 Mr. Webster gave a brief notice of injuries to young cab- 

 bage near Dayton, Ohio (Bui. 2. n. s.,pp. 90, 91), and later furnished 

 a more complete account (Bui. 77, Ohio Agl. Expt. Sta., pp. 50-52). 

 In the Canadian Entomologist of March, 1896 (Vol. XXVIII, pp. 

 59-61), under the title " CeutorhyncTms nccpi or Ceutorkynchits rapce" 

 the same writer also published an article on this species, together with 

 illustrations of the beetle, its larva and its work. 



RECENT OBSERVATIONS ON THE BIOLOGY OF THIS SPECIES. 



Upon opening a stem of hedge mustard, May 5, in the locality 

 infested by the beetles on the Department grounds, no less than a 

 dozen eggs were disclosed in the first inch and a half of the stem just 

 beneath the flowers. They were resting in the pith, where they were 

 inserted through punctures made in the stem by the rostrum of the 

 parent beetle, the scar showing the place of deposit. 



That the beetles appear much earlier, and egg deposition is conse- 

 quently earlier than the first of May, was proved by finding in the same 

 stem and in others toward the base numerous larvae, some nearly full 

 grown. Injury by this weevil to cabbage at Glasgow, Mo., as reported 

 by Miss Murtfeldt, was noticed the latter part of April. 



May 9, 1899, in a search for this species at Tennallytown, D. C, 

 the beetles were found to occur but rarely on turnips, but were more 

 abundant in the same garden in a bed of horse-radish. 



At about this time it was noticed that the larvae, as they approached 

 maturity in hedge mustard, cut holes through the stalks, usually on 

 the lower side of the axil of the branch or leaf -stalk. It was not 

 ascertained just when the larvae left the stems, but from the size of the 

 openings toward the middle of May it is probable that some had 

 already begun to desert the stems to enter the earth. Stems examined 

 May 20 were found either to have been vacated or the larva? were just 

 completing their growth or preparing to cut their way out. 



From what has been said of the number of eggs deposited in a stem 

 it follows that many larvae occur in a plant. Judging from some 

 examined, sixty or more larvae often find lodgment in a single stem and 



