PREEACE, 
The boll weevil has been present in the United States for fourteen 
years. At this time it is doing serious damage to cotton in four 
States, and during the present season undoubtedly will invade a fifth. 
In regions like Central America, where the insect has existed for 
many years, there are various influences that serve to hold it in 
check. In this country similar influences are beginning to be in 
evidence. Among the direct factors in the natural control of the 
boll weevil that are now at work are the following: Heat and dry- 
ness, the native ant Solenopsis geminata,* winter temperatures, 
proliferation, parasites, defoliation by the cotton leaf-worm, deter- 
minate growth, and birds. Of these, proliferation and birds have 
already received careful special attention, while the work of the 
native ant has received preliminary notice. The other factors have 
also been more or less discussed in the publications of the Bureau 
of Entomology and elsewhere, and more extensive studies of certain 
ones will be discussed by Dr. W. E. Hinds in Bulletin No. 74 of this 
Bureau. 
While the work of parasites, discussed in this bulletin, is not at 
present one of the most important factors in the control of the boll 
weevil, the indications are clear that its importance will grow rapidly. 
Moreover, the matter has special interest for the reason that it is 
not unlikely that practical means may be devised to increase the work 
of the parasites. 
In the United States fifteen species of insects which seek the weevil 
in its immature stages are known. These insects have not been 
introduced artificially from other countries, nor have they followed 
the boll weevil into this country. They have all been present for 
years, and have been actively parasitic upon other species of weevils 
found within the boll-weevil-infested territory. In fact, there are 
a great many closely related weevils of the genus Anthonomus, some 
of which are very common in parts of the cotton belt. These weevils 
are frequently held completely in control by parasites, and for the 
most part the parasites are not confined to the attack of a single 
species of weevil. In many cases the boll weevil may appear in a 
@Not to be confused with the kelep, the introduction of which has proved unsuc- 
cessful. 
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