476 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 7 



garded as a "cure all" for the brown-tail moth, but is very important 

 as a powerful check. 



They give the following directions for the use of the fungus: "The 

 Entomophthora under consideration may be used effectively in the 

 spring and early summer, when the larvse have left their nests and in 

 the autumn for several weeks before the webs of the new broods are 

 closed for the winter. During both of these periods the rapid spread 

 of the disease is largely dependent on weather conditions, and when 

 these conditions — warm nights and damp atmosphere — favor the 

 growth of the fungus, artificial distribution yields truly satisfactory 

 results, and may bring about enormous and widespread destruction." 

 . . . "In the spring, when the caterpillars are scattered all over 

 the trees, it is comparatively easy to place the infected larva? in among 

 them, but in the autumn, when they are localized, feeding in the 

 immediate vicinity of the nest, it is necessary to infect individual nests. 

 Experience seems to point to the autumn, however, as the more advan- 

 tageous time to start the artificial epidemic." 



A detailed account of the methods used for the propagation and 

 dispersion of the brown-tail fungus will be found in the paper of these 

 authors. Suffice it to say that the fungus has accomphshed much 

 good and when the proper conditions for its introduction are selected, 

 a destruction of from 63 to 100 per cent, of the caterpillars in the 

 planted areas can be depended upon. An intelligent use of the brown- 

 tail fungus should be encouraged, for the results obtained in Massachu- 

 setts during the last two or three years justify a serious consideration 

 of the matter. Professor Roland Thaxter, the well-known crypto- 

 gamic botanist, told me that he could not think of any waj^ in which 

 the State Forester of Massachusetts could spend a few thousand 

 dollars a year to better advantage than in the propagation and dis- 

 persion of the brown-tail fungus. 



ON THE CAPTURE OF LIVING INSECTS BY THE CORN- 

 FIELD ANT (LASIUS NIGER AMERICANUS) 



By Wesley P. Flint 



During some experimental work on the corn-root aphis done at 

 Bloomington, 111., in the summer of 1909, the movements of Lasius 

 americanus were closely observed every night for nearly two months 

 by Mr. G. E. Sanders and myself. It was frequently noticed that on 

 warm nights, when these ants were very active, they would attack 

 and kill many small insects that came near their nests. This was 

 first seen on a very warm night in August, when a large nest of ants 



