THE SO-CALLED TOBACCO WIREWORM IN VIRGINIA. 29 



(4) The worms when once established in land where their natural 

 food plants are abundant have been found difficult to control. 



(5) Various insecticides and repellents have been tested, but 

 without satisfactory results. 



(6) Fall or winter plowing has been found to reduce injury, but 

 is only partially effective, as some of the weeds remain alive and 

 furnish food for the larvae until the tobacco or corn is planted. 



(7) Damage is best prevented by crop rotations, or by cultural 

 methods that prevent growth of the weeds which are food plants of 

 the worms, thus making conditions unfavorable for egg deposition by 

 the moths the summer before tobacco or corn is planted. Summer 

 plowing, thorough preparation of weedy land, and the growing of 

 crops of cowpeas or crimson clover, preferably cowpeas, the year 

 before crops subject to injury are planted, have been found to be the 

 most satisfactory and practical means of control. 



BIBLIOGRAPHY. 



I860. Clemens, Brackenridge. Contributions to American lepidopterology. No. 

 5. Proc. Acad. Nat, Sci. Phila. for I860, p. 203-221, June, 1860. 



The original description of Crambus caliginosellus, p. 204. 



1880. Grote,A.R. Preliminary list of North American species of Crambus. Canada 

 Ent., v. 12, no. 4, p. 77-80, Apr., 1880. 

 Gives habitat, N. Y., p. 79. 

 1887. Moffat, J. A. Further additions to the list of Canadian microlepidoptera, 

 Canad. Ent., v. 19, no. 5, p. 88-89, May, 1887. 



Specimen of Crambus caliginosellus in collection of Mr. Moffat, Hamilton, Ont., deter- 

 mined by Fernald. 



1891. Beckwith, M. H. Notes on a corn crambid. U. S. Dept. Agr., Div. Ent., 

 Insect Life, v. 4, no. 1-2, p. 42^3, Oct., 1891. 



Brief mention. Dr. J. B. Smith reports insect as injuring corn in New Jersey. Dr. L. O. 

 Howard reports insect as abundant in Maryland in 1886. 



1891. Beckwith, M: H. Notes on a corn crambid. Del. Col. Agr. Exp. Sta., Bui. 

 14, p. 13-15, fig. 1, Dec, 1891. 



Mention of species as injurious to corn in Delaware. Account of feeding habit of larvae. 

 1894. Felt, E. P. On certain grass-eating insects. Cornell Univ. Agr. Exp. Sta., 

 Bui. 64, p. 47-102, 14 pis., Mar., 1894. 



"The sooty crambus," p. 61-62. Brief account of moth; description of eggs and newly 

 hatched larvae. 



1896. Fernald, C. H. The Crambidse of North America. Mass. Agr. Col. Ann. 



Rpt. 33 (Pub. Doc. 31), p. 77-165, pis. 6 & A-B, Jan., 1896. 

 Redescription of moth, p. 137-138. 



1897. Johnson, W. G. Notes on some little-known insects of economic importance. 



U. S. Dept. Agr., Div. Ent., Bui., n. s., no. 9, p. 83-85, 1897. 

 " Crambus caliginosellus," p. 84. Account of injury to corn in Maryland. 



1898. Johnson, W. G. Report on the San Jose scale in Maryland and remedies for 



its suppression and control. Md. Agr. Exp. Sta., Bui. 57, 116 p., 26 figs., 

 Aug., 1898. 



'•' Crambus calignosellus," p. 9. Account of injury and feeding habits of larvae. 



1898. Johnson, W. G. Notes from Maryland on the principal injurious insects of 



the year. U. S. Dept. Agr., Div. Ent., Bui., n. s., no. 17. p. 92-94, 1898. 



"The corn crambus," p. 93. Brief mention as destructive in various parts of the State. 



