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 Circular No. 107. 
 
 United States Departing!) <>i A 
 
 BUREAU OK ENTOMOLOG 
 
 L. O. HOWAKI). I 
 
 WHAT CAN BE DONE IN DESTROY! 
 WEEYIL DURING THE 
 
 By W. I>. Huntbr, 
 In Charge of Southern "Field Crop I 
 
 IMPORTANCE OF WINTl'.K WORK. 
 
 boll weevil attar test attention daring tin- growing season 
 
 of cotton, for tin* simple reason that its damage ia then moat evident. 
 When the infest d Bquan - ling by millions everyday the planter 
 
 is driven to most Btrenuoufl efforts to check the loss. The summer 
 er, is the one in which it is most difficult to combat the 
 il. The ] ! he attaeked in various ways at different seasons 
 
 of the year. This circular attempts to point out what can be done in 
 the winter when the weevils are in hibernating quarters and when nat- 
 ural conditions are assisting the tanner greatly by reducing the number 
 that will he able to survive until spring. At this time the farmer can 
 Undoubtedly accomplish more than by hand-picking weevils and squares 
 or any other direct method of control that can be put into operation in 
 the summer Beason. advantage that winter work has in many 
 
 is that it involves no special outlay and consequently adds nothing 
 to th "f producing cotton. The work can be done during the 
 
 quiet period of the winter and at such times as will not interfere with 
 
 •neral work of the plantation. Even on plantations run largely or 
 entirely by "wages hands" this work woull undoubtedly warrant an 
 outlay on the part of the planter. As a matter of fact the winter season 
 COUld well he made the most active of the year as far as the destruction 
 of the weevil is concerned. 
 
 It is true that the Texas farmers have not paid much attention to 
 work against the weevil in the winter, hut this does not by any means 
 indicate that such work will not he of prime importance to the planters 
 
 ppi. Nature has afforded the Texas tinner 
 many advant inter in 1 rn part of the cotton belt. 
 
 As ha- been pointed out in other publications of the Bureau of Ento- 
 mology, the ' ppi Valley planter will he compelled to contend 
 
 -t many more weevils each spring than the climatic conditions in 
 •er permitted to survive. For instance, in the spring of 
 etermined by Mr. Wilmon Newell, secretary of the 5 
 crop pest commission of Louisiana, that as many as 6,0<X) hihernated 
 weevi re made their appearance in certain cotton fields in Avoy- 
 
 elles Parish, Louisiana. This a survival of weevils far heyond 
 
 what has ever been found in Texas. There are many other indications 
 of the special seriousness of the weevil problem in the .Mi-sir?ippi Val- 
 
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ley. All this demonstrates that the planters in regions recently invaded 
 by the weevil must resort to every means of control that is known and 
 must utilize to the fullest extent such methods as the Texas farmers 
 may not have been compelled to practice. 
 
 The all-important- step in the control of the weevil is the destruction 
 of millions of individuals and the prevention of the development of 
 many more by uprooting and burning the cotton plants in the fall. 
 This is a step that indications show clearly is going to be indispensable 
 in the Mississippi Valley. In the light of what is now known it would 
 be folly for planters to attempt to produce cotton unless they follow 
 this practice religiously. If, for any reason, the cotton plants have not 
 been removed in the fall, some good can be accomplished by their 
 removal later in the season. The proper thing to be done by the 
 planter who desires to reduce weevil damage to the minimum is to 
 combine the fall destruction of the plants with such measures, to be 
 taken later in the season, as are outlined in this circular. The advice 
 now given is not to depend upon winter work altogether for the control 
 of the weevil. The winter work is merely a second step, to be taken in 
 connection with the destruction of the weevils and the prevention of the 
 maturity of the fall broods by uprooting and burning the plants. Where 
 that step has not been taken, the work outlined in this circular is the 
 main dependence of the planters at this time. 
 
 WHERE WEEVILS ARE TO BE FOUND DURING THE W r INTER. 
 
 The whole question of what can be done to destroy the weevils in 
 the winter depends upon where they are to be found. The Bureau of 
 Entomology has taken pains to determine the localities in which the 
 weevils secrete themselves during the winter months. Some weevils 
 fly outside of the cotton fields into the timber before frost has killed the 
 cotton. Of course, such individuals as fly great distances from the 
 cotton fields, or into heavy timber, are entirely beyond the reach of the 
 planter. The remainder of the weevils, how 7 ever — those remaining in 
 and about the cotton fields — are more or less at the mercy of the 
 planter for several months during the winter. 
 
 In cotton fields and in their immediate vicinity weevils have been 
 found hibernating in four principal situations: First, in burrs and un- 
 opened bolls on the plants ; second, in bolls or portions of bolls that 
 have been knocked to the ground; third, under such trash as leaves 
 and grass abounding in most cotton fields; fourth, in the cracks in the 
 ground caused by drying. 
 
 The numbers of weevils found in the situations just mentioned show 
 clearly what opportunities the farmer has for their destruction. On 
 January 16, 1907, a field near Wolfe City, Tex., showed from 363 to 
 1,500 live weevils per kcre in the burrs still hanging to the plants. 
 These were generally in the partly opened locks where weevils had 
 matured in the fall, but some were in locks from which all of the cotton 
 had been removed. On January 27, 1907, as many as 2,250 weevils 
 per acre were found on the ground in a cotton field near Dallas, Tex. 
 The number was determined by raking all of the trash carefully from a 
 square rod of ground and examining it in the laboratory. On Decem- 
 ber 18 living weevils at the rate of 1,056 per acre were found at Dallas. 
 On January 16 320 living weevils per acre were found in burrs and 
 under leaves and grass in a cotton field at Victoria, Tex. On Novem- 
 
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her 1 "> 1 weevils were found in the ciacks around the bftMfl of 22 
 cotton plants growing near Dallas. This indicates a total Dumber of 
 
 uc.vils per a, re in such situations in this field of 1,090. 
 
 Practically all of the weevils to be found in the situations described 
 can be killed by raking and burning the trash, excepl those in cracks 
 in the ground, and these, in the majority of cases, would probably be 
 crushed by winter plowing of the fields. 
 
 PLOWING NOT EFFECTIVE. 
 
 The point may he raised thai winter plowing, by burying the weevils 
 found iii trash on the surface, migbl have the same . burning. 
 
 On the contrary, experiments have shown that weevils can easily make 
 their way through several inches of soil. Consequently such work in 
 genera] is as likely to protect as to destroy the weevils, of course, it 
 heavy rams should follow immediately after plowing, it is possible that 
 some soils would he so compacted as to prevent the emergence of 
 weevils. Nevertheless, this could not happen under usual conditions. 
 In the case of weevils in cracks, destruction would not result from 
 burial hut from crushing. 
 
 What lias jusl been stated should not he taken to mean that winter 
 plowing should not be followed. As a matter of fact, the winter work- 
 ing of the fields should he practiced, not only on general principles, hut 
 --ist in procuring an early crop. The present purpose is merely to 
 point out how to destroy the boll weevil in the winter. Regardl< 
 
 ther benefits, winter plowing can not he depended upon to actually 
 kill many weevils. 
 
 WEEVILS THA'f CAN BE BEACHED OUTSIDE or COTTON FTELD8. 
 
 In addition to those in the cotton fields themselves, many weevil- 
 can he reached that have found winter quarters along turn-row-, in 
 ditches, along fences, and in the trash that is frequently allowed to 
 accumulate around seed houses. Fire is again the agent of destri; 
 at the com m anil of the fanner. Careful burning of turn-rows and ditches 
 and cleaning of fence corners and similar situations w ill result in the 
 death of many weevils that might survive to damage the crop of the 
 following season. 
 
 The work of burning and cleaning the plantation should not stop 
 with the immediate vicinity of cotton fields. Many weevils By into 
 corn fields, where they find suitahle quarters for passing the winter. 
 These fields, on a cotton plantation, should he cleaned during the win- 
 ter as thoroughly as the fields where cotton has been growing or is to be 
 grown during the ncv - - . It has been found that sorghum fields 
 furnish exceptionally favorable opportunities for hibernating weevils. 
 The heavy Btubble left by this crop catches grass and general debris 
 blown about by the wind, which then becomes heavily matted. Here 
 many weevils are to he found during the winter. In many cases in 
 - the earliest appearing weevils and the greatest damage to the 
 crop have been shown to he chargeable to neighboring Borghum fields 
 which have served as winter quarters for the pest. 
 
 Many weevils undoubtedly find hibernating quarters in trash a 
 railroad rights of way as well as along wagon mads. The importance 
 of such means furnished the weevil for passing the winter 1 great 
 
 where, as in many cases, the roads or railroads pass through localities 
 
UNIVERSITY OF FLORIDA 
 
 II I Mill II II II' 
 
 3 1262 09216 5132 
 
 where cotton fields adjoin the public property. It should be the duty 
 of railroad and county authorities in such cases to assist the farmers as 
 far as practicable by removing the shelter for the weevil. 
 
 WEEVILS IN COTTON SEED. 
 
 Cotton seed has frequently been supposed to furnish exceptionallv 
 favorable winter quarters for the weevil. It has been shown that mam 
 weevils pass through the gins and are later to be found in the bulk i 
 ton seed in storage. Up to a certain time in the winter cotton seed i« 
 very likely to contain live weevils. Many experiments, however have 
 shown that very few are able to survive in this medium until spring 
 This seems to be due principally to the absence of moisture. Repeat- 
 edly numbers of weevils have been placed in cotton seed in the fall 
 Altogether 6,600 weevils have been used in these experiments. They 
 were placed under a variety of conditions. Although many have sur- 
 vived until the middle of winter, only two lived until the first of April 
 It is therefore clear that cotton seed itself is not an especially dangerous 
 commodity. Although it is true that the earliest weevils frequently 
 make their appearance in the vicinity of seed houses, this is to be 
 accounted for by the fact that the insects find quarters under the build- 
 ing and under the trash that is allowed to accumulate in such situations 
 rather than in the cotton seed itself. 
 
 CONCLUSION. 
 
 The climatic and labor conditions surrounding cotton production in 
 Louisiana and Mississippi leave no doubt that the planters in those 
 States must not overlook any important means of controlling the boll 
 weevil. This circular points out one important and inexpensive means 
 that can be practiced by every planter. It is of special importance in 
 the humid regions recently invaded where fears of disaster are now 
 commonly entertained. The Department of Agriculture urges that 
 cotton raisers take advantage of the enemy while they have the oppor- 
 tunity and by the means herein described greatly increase the chances 
 for producing a crop the coming season. 
 
 Approved: 
 
 James Wilson, 
 
 Secretary of Agriculturi . 
 
 Washington, D. ('.. December t9, 1908. 
 
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