NATURAL CONTROL. 139 



When the plants become defoliated by the leaf worms the growth is 

 checked, and consequently the opportunities for the breeding of the 

 weevils in additional squares are reduced. This results in a marked 

 decrease in the number of weevils at the end of the season. This 

 decrease has not so much effect upon the crop of the current year as 

 upon the following one by reason of the lessened number of weevils 

 that pass through hibernation. Moreover, when the plants have been 

 deprived of most of their leaves the worms very frequently devour 

 the squares and sometimes small bolls in which the immature stages 

 of the boll weevil are located. In this way the leaf worm acts directly 

 as a remedial agenc}^ against the boll weevil. This work to some 

 extent accomplishes the same result as the fall destruction of the 

 plants, which, as is well known, is the greatest 

 single factor in the successful production of 

 cotton in weevil-infested regions. There is still 

 another consideration in this connection, 

 namely, that the defoliation of the plants allows 

 the sun to strike the squares upon the ground. 

 thus destroying many of the larva? and pupae of 

 the weevil contained therein. At the present 

 time, as the result of the conditions mentioned, 

 the planters in the infested regions are rapidly 

 giving up the practice of poisoning the formerly 

 much dreaded caterpillar. If, as may occa- 

 sionally happen, the plants become defoliated 

 before the weevils reach the maximum numbers 

 in the fields, the damage of the one insect will fig. zz.~Hydnoccra pubescens, 

 simply be added to the damage of the other. In ^3° f the bo11 "^ 

 that event the use of poison will be necessary. 1 



In the extensive defoliation by the leaf worm in 1911 one of the 

 most striking features was the scattering of the boll weevil for great 

 distances into new territory. The general absence of green fields 

 caused the weevils to fly much farther than they would otherwise 

 have done. 



HYMENOPTERA. FORMICOIDEA. DORYLID^E. 



Eciton (Acamatus) commutatus Emery (PI. XVI, a). — This ant has 

 been observed only once, at Beeville, Tex., attacking the weevil 

 larvae in squares. 



PONERID.E. 



Ectatomma tuberculatum Olivier. — The ''kelep," or so-called Guate- 

 malan ant, is a native of Mexico and Central America. Like all other 

 ponerids, it is slow in action, but is able to capture such weevils as 

 come within its reach on the cotton plants. Numerous attempts to 

 establish this species in the United States have failed. 



MYRMICID^E. 



Cremastogaster lineolata Say, subsp. Jseviuscula Mayr, var. clara 

 M;ivr. (PI. XVI, b). — This ant, although normally a honeydew feeding 

 species, is also an enemy of the immature stages of the boll weevil in 

 Texas. 



Solenopsis geminata Fabricius, var. diabola Wheeler. — The common 

 fire ant of the Southern States is one of the best enemies of the boll 



*^7 he al >9 ve paragraph is from W. D. Hunter in the Yearbook of the Department of Agriculture for 

 1904, p. 201. 



