CIRCULAR NO. 20. 



t ?u P J lth hls cotton - He can Pl^t so that the sun will set in 

 its full effect. It is now known that the intense heat from Srec 

 exposure to the sun is responsible for the death of 32 per cent of all 



r a e ch slSst 9 T h n ^T *! S ° me PlaC6S Unde1 ' **™lueZn<£ionl 

 leaches almost 90 per cent. At the same time the little fire ants (see 



l\TJlm\TT y 2 ° t Pe ^ Cent of a11 ^ weevil stages, and the pira 

 sites kill 10 per cent. This means that THROUGHOUT THE SUM 



kTled P Th er ; ENT ° F ALL THE WEEVIL stage U s T are E b S E Yno 



KILLED. There are many favorable conditions which increase the 

 work of one or another of these agencies. The figures just given are 

 for 1907, and show a decided increase over 1906 



One of the purposes of the boll weevil investigation is to brine 

 about a knowledge of the weak points in the life history of the insecl 

 so that every planter will know when and where to strike in order to 

 accomplish the best results. IT IS WITHIN THE POWER OF EACH 

 FARMER TO LESSEN THE DAMAGE BY THE WEEVIL but much 

 more is accomplished by the natural agencies referred to 



valulnf t°hi eCt ° f -, thiS C / rCUlar iS t0 explain the natuie ^ Possible 

 ™e art fill P ^ T W i UCh are m ° re difflCUlt t0 under «tand than are 

 the artificial methods of controlling the weevil. Verv little can bo 



selves The"!: 11 ' '" ^^ the ^ ^ Wi " tak « Care ^ "em- 

 BP^INrREASFn e r/ eaSOnS I'"' the PARASIT ES, however, can no: 

 Sfo ying agfnS. *""* ^ *« ^ *"* " bo11 weevi] de " 



ASSISTING THE PARASITES. 



The planter who desires to offer every possible inducement to the 

 parasites will plant his cotton early so that the first spring broo d of^ 

 parasites can start on the boll weevil instead of some other neighboring 

 species of weevil. He will PLANT his cotton IN WIDE ROWS and 

 use every device to insure plenty of sunlight in the entire field Thes^ 

 htt e creatures need heat and light and work best in the sunny fields 

 thus adding to the direct effect of the sun itself 



When it can be done without taking labor from the necessarv field 

 operations it is a good plan to pick up infested cotton s'uaTes and 

 Place them in large cages i n the field, a plan which was first brou eh 



roTX'rroV^e'rP^ " ° f - the L ° Ul8iana P,anterS ^^ Circulai No 

 cages mav L of ™ C ° mm,ssl0n ' Published early last June. These 

 cages may be of common wire screen, 14, 16 or 18 meshes to the inch 

 Some weevils will escape through the coarser meshed wire and aM 



"nd a,, P o a f ra tbe e n; V,1, V Bve " * 0n,y h&,f ° f the weevils ™ held t 

 and all of the parasites escaped it can readily be seen that the oro 

 Portion of parasites to weevils in the field would be Neatly increased 

 The squares should be dried a little before placing i the cage or at 

 any rate scattered lightly. They should not be packed for then the 

 moulding and heating would destroy the parasites Cages placed in 



weevT ^r 7 J* 16 fie ' d Wi " brlng "P the Parasitic contro of tn" 

 weevil uniformly.' Immediate results must not be expected Owin* 



when LTSl ih 6 U r f raSiteS Wl " rare * be see « by the armei "e? 

 When they are abundant a nd doing great work. The benefits are actual 

 but hard to demonstrate without very careful examinluons & 



many pa^iteTof nT.' ** T""" ""*■ &r ° Und the fieIds ™^» 

 WEEDS porU ^II^ 11 is P^sible BY PUTTING these 



,V,£™;r T FORCE the PARASITES TO ATTACK THE ROT T 



oT™e V B ur enu n ofS ", """ k ' M '" ** « «»e ex?e„™„ E ,a, B 2S 

 Bureau of Entomology at Dallas, Texas, resulted In Increasing 



*««sw»nsffl^aaia&.*5*- 



ight box or barrel, with 



