THE TOBACCO SPLITWOEM. 



PARASITES. 



Kotinsky^ records two larval parasites, CTielonus hlacJchurni Cam. 

 and Limnerium polymesiale Cam. About 25 per cent of the full-grown 

 larvse of a large shipment of splitworms, sent by Mr. G. A. Runner late 

 in August, 1913, from Kinston, N. C, were parasitized. Several 

 parasitic larvse emerged from each splitworm which was killed at or 

 just before the emergence of the parasite, and while still in the mine. 

 The parasites spun their cocoons in the mine and sometimes within the 

 larval skin. A single splitworm from which this parasite was reared 

 was included in another large shipment of material sent by Mr. Runner 

 from Appomattox, Va. Larvse of this parasite which emerged from 

 the host September 1, 1913, pupated September 3, and the adults 

 emerged September 10, giving a pupal stage of seven days. 



REMEDIAL MEASURES. 



Quaintance * recommends the destruction of the larvse in the mines 

 by pinching, and the destruction of all trash in and around tobacco 

 fields and tobacco barns. Both of these recommendations should be 

 followed. However, in severe infestations it may be necessary to 

 prime off and destroy the leaves infested by the earlier generations. 

 A heavy infestation would ruin the leaves for wrappers, in which case 

 the priming and destruction of the leaves wUl be a cheaper and more 

 thorough method of destruction, for it will cause the death not only of 

 the larvse but also of a large number of eggs. This plan was pursued at 

 Dade City, Fla., following the severe infestation of 1908, and with 

 excellent results. Since that year, also, the crop has been transplanted 

 much earlier than was the custom previously, and was matured before 

 the appearance of the most destructive generation of the splitworm. 

 Loss has been very light since 1908. 



To summarize the remedial recommendations: (1) Transplant the 

 crop as early as possible, in order to mature it before the appearance of 

 the most destructive generation of the splitworm; (2) when the early 

 infestation is very severe, prime off and destroy the infested leaves; 

 (3) destroy all tobacco stubble as soon as the crop is harvested to pre- 

 vent the breeding of a hibernating generation; (4) clean up and de- 

 stroy all trash in and around tobacco fields and tobacco barns ; (5) do 

 not follow potatoes by tobacco, for the infestation of tobacco has been 

 more severe in such cases than where a different rotation was followed ; 

 (6) grow potatoes as far as possible from tobacco fields. 



1 Kotinsky, Jacob, 1906. Hawaii. Forester and Agr., v. 3, no. 7, p. 200-201. 



2 Quaintance, A. L., 1898. Tlie tobacco leaf-miner (Gelechia picipellis Zett.). Fla. Agr. Exp. Sta., Bui 48, 

 p. 178-181. 



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