FIELD OBSERVATIONS ON SUGAR-CANE INSECTS. 6 



borer. Cane has been groAvn for years at Victoria for sii'up making, 

 and it is unlikely that any new varieties have been introduced there 

 in a generation. 



It seems e\adent from these examinations that the moth borer has 

 never entered certain restricted districts, while it has probably been 

 imported with shipments of seed cane to places where an effort has 

 been made to obtain new and better varieties of cane. The presence 

 of the moth borer in Louisiana is accounted for by the belief that it 

 was introduced in sliipments of sugar cane from the Tropics, while its 

 presence m the Rio Grande Valley is probably due to accidental intro- 

 ductions from Louisiana or Mexico, provided it is not native to that 

 part of Texas. HoAvever this may be, the moth borer is evidently 

 absent from the sirup-producing regions of Texas and Louisiana, 

 where sugar cane is grown only as an incidental crop, while the insect 

 is present m the sugar-producing regions (except at Sugar Land) where 

 sugar cane is of vital miportance and where new and better varieties 

 are desired and obtamed. The results from exammations in Ala- 

 bama and Mississippi concern sirup-producmg communities, and agree 

 with the results from Texas and Louisiana. These fhidings go to 

 strengthen the position that introductions of sugar cane should be 

 made with great care if injurious insects are to be excluded. 



A m.ost noteworthy result of the examinations during the year is 

 the discovery of eggs of the moth borer attacked by the hymenop- 

 terous parasite Triclwgramma minutum (pretiosa) RUey, by Mr. 

 Gilbert E. Bodkin, Government economic biologist of British Guiana, 

 South America. Examining sugar cane with the WTiter at Audubon 

 Park, New Orleans, in September, he found the black egg masses of 

 the moth borer on the leaves of the plants. Being familiar with the 

 work of the parasite in British Guiana he was sure that the eggs were 

 parasitized. Parasites were afterwards reared from the eggs by the 

 writer, and they were found to be of the species mentioned, which 

 occurs in many places in this and other countries. The parasite, 

 however, had not previously been reared from eggs of the moth borer 

 in the United States. 



Later the writer found parasitized eggs of the moth borer near 

 Brownsville, Tex., Domia, Tex., Donaldsonville, La., and Franklin, 

 La. 



The larvae of a predaceous beetle were found on sugar cane by 

 Mr. E. R. Barber, near Montgomery, Ala., on October 26, and by the 

 writer near Baton Rouge, La., and La Fayette, La., in October, and 

 near San Benito, Tex., m November. These larvae were not observed 

 to attack the borer, though they may do so. 



Evidences of larval parasites of the borer were detected at a number 

 of places, but these are somewhat doubtful. 



[Cir. 171] 



