92 



IlSrSECT ENEMIES OF THE BOLL WEEVIL. 



ing squares; in September, 1906, this had risen to 10.2 per cent; in 

 July, 1907, the parasitism by tliis species was 35.2 per cent, and in 

 August, 1907, it had risen to 39.8 per cent. 



At Shreveport, La., in 1908, many specimens of Catolaccus incertus 

 and Microhracon mellitor were released. Table XXII gives an idea of 

 the results and shows the expected increase by Catolaccus in both 

 hanging and fallen squares and by IVIicrobracon in hanging squares. 



Table XXII. — Experiment in artificial inlroduction of Catolaccus incertus and 

 Microhracon mellitor, Shreveport, La., 1908. 



RELEASE CAGES. 



In order to obtain satisfactory results from the release of infested 

 material, it is necessary to place the material in cages from which 

 the injurious weevils can not escape but which will still allow the 

 parasites egress. This principle has been explained in other sections. 

 There is also another important consideration in the construction of 

 the cages. When a large amount of material such as this is collected 

 in a small space it furnishes great inducements to attack by colonies 

 of ants. The only way that the material can be protected from total 

 destruction by ants is the isolation of the cage on legs by the use of 

 "inverted cups" containing oil, or by greasing the legs in some 

 manner. 



TRANSFER OP ANT COLONIES. 



Since the work of ants is always very favorable to control, means 

 should be devised of increasing their numbers in the cotton field. 

 The dust-mulch method of cultivation is very favorable to the ants 

 in that it does not disturb their colonies after they have commenced 

 breeding. Tliis is a very important matter to consider. The late 

 Mr. F. C. Pratt, in working with the horn fly {Lijperosia irritans 

 L.) discovered that fresh manure containing numerous fly larvae 

 is very attractive to Solenopsis, and that these ants seem to trans- 

 fer their whole colony at times to the manure. Mr. Wilmon NeweU, 

 in connection with the Argentine ant investigations, at a later 

 date, found that he could trap immense colonies of the Argentine 



