62 BULLETIN 746, U. S. DEPARTMENT OP AGRICULTURE. 



No other parasites were found during the succeeding two years, 

 and it would appear that they have died out, but the discovery of 

 the single puparium proves that they will successfully parasitize the 

 sugar-cane moth borer in Louisiana. It is believed by the writers 

 that the parasite might be of much benefit in controlling the borer if 

 it were introduced in larger numbers. If this had been possible, 

 much might have been accomplished, but conditions in 1916 and 1917 

 prevented further experimental work. 1 



If the introduction of beneficial parasites can be undertaken later, 

 it would seem advisable to station two men in Cuba to collect the 

 parasites and one in Louisiana to receive them and ultimately to 

 release them on the plantations. In 1915 investigations were con- 

 ducted from February to September, but it appears that the most 

 favorable season is from April to September, inclusive. 



RECOMMENDATIONS. 



1. Scraps of cane left about the factories and derricks after the 

 grinding season should be destroyed by burning or otherwise. Cars 

 in which cane is shipped, especially if they go into noninfested terri- 

 tory, should be kept free of such scraps. 



2. Seed cane should be planted in the fall, if possible, and kept 

 as deeply covered as practicable. Extraordinarily deep planting is not 

 advocated, but as borer moths fail to emerge from cane under more 

 than one-half inch of compact soil care should be taken to keep the 

 seed cane well covered to that depth as a minimum. A heavy rain 

 will sometimes wash the earth from the seed cane from one end of a 

 row to the other, and in this case it is important to cover the cane 

 again as soon as possible, especially in the spring, when the moths are 

 emerging. 



3. Cane for shipment to points beyond the infested area should be 

 selected so as to obtain it sound and free of borers, or if this is im- 

 possible it should be soaked, previous to shipment, for at least an hour 

 in Bordeaux mixture 2 or a solution of nicotine sulphate. 3 



1 Since the manuscript for this bulletin was submitted a number of sugar planters in 

 Louisiana have agret'd to contribute a small amount each to enable work in Cuba to be 

 done. This action made it possible for the senior author to spend some time in Cuba in 

 1018. lie collected and sent to New Orleans about G50 puparia of the tachinid Eussenil- 

 liopsis diatracae, which were received and cared for by. Messrs. E. R. Barber and W. G. 

 Taggart. Several generations were reared during 1018, and it seems that the parasites 

 will become established if they can stand the Louisiana winter. 



The junior author, who was in Cuba in 1015, is no longer connected with the investi- 

 gation, having accepted a position under the Federal Horticultural Board. 



2 The formula for Bordeaux mixture is as follows: 



Sulphate of copper pounds G 



Quicklime do 4 



Water gallons— 50 



Dissolve the sulphate of copper in 1 gallon of hot water and slake the lime in another 

 vessel with an equal quantity ; reduce the latter to a creamy milk of lime and add slowly 

 to the copper solution, stirring constantly. Finally, add water to make up the 50 gallons. 



3 One part nicotine sulphate (40 per cent nicotine) to 500 parts water. 



