92 



II^SECT ENEMIES OP THE BOLL WEE^TiL. 



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

 July, 1907, the parasitism by this 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 Microbracon 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 Microbracon in hanging squares. 



Table XXII, — Experiment in artificial introduction of Catoloccus incertus and 

 Microbracon mellitor, Shreveport, La., 1908. 





Plat. 



Date. 



Percentage of mortality. 



Gain in mortality. 



Class of forms. 



Total. 



Para- 

 sites. 



Cato- 

 laccus. 



Micro- 

 bracon. 



Total 

 para- 

 sites. 



Cato- 

 laccus. 



Micro- 

 bracon. 



Fallen squares 



Eelease... 

 ...do 



Check 



...do 



Release... 

 ...do ._ 



Oct. 5 

 Oct. 28 

 Oct. 5 

 Oct. 28 

 Oct. 5 



36.44 

 37.96 

 40.00 

 42.33 

 47. 15 



5.93 

 15.74 

 10.50 

 16.00 



9.90 

 37.84 



4.23 

 10.80 

 5.55 

 8.00 

 4.39 

 10.81 



1.70 

 2.16 

 3.70 

 5.00 

 3.29 

 18.91 



Per cent. 



Per cent. 



Per cent. 



Do 



Do 



165 



150 



33 



Do 



Hang ing squares. . . 



52 



44 35 



Do 



Oct. 29 fi4.Sfi 



282 



148 477 



1 















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 stiU 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 smaU 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 uss of 

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

 manner. - 



TRANSFER OF AXT COLOXIES. 



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. This is a very important matter to consider. The late 

 Mr. F. C. Pratt, in working mth the horn fly (Lyperosia 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 XeweU, 

 in connection with the Argentine ant investigations, at a later 

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



