58 EXPERIMENT STATION KECORD. 



use of kerosene and coal-tar water. Results with kerosene emulsion and with 

 turpentine were conflicting. 



"Indoor pot-plantings in 1906 showed no injury after a moderate use of 

 kerosene, oil of lemon, carbolic acid, formalin, lysol, chlorid of lime, carbon 

 bisulphid, tobacco water, or camphor. Soaking in common alcohol for 30 min- 

 utes or in wood alcohol for 20 minutes, injured the seed. 



" Extensive field experiments were made in 1906 with minimum quantities 

 of oil of lemon, kerosene, formalin, and carbolic acid applied to seed just before 

 planting. Examination 6 weeks after planting showed average diminution of 

 number of root-lice and of hills infested by them, as follows: Oil of lemon, 76 

 per cent; kerosene, 57 per cent; formalin, 49 per cent; carbolic acid, 8 per cent. 

 Ten weeks after planting, corn in the experimental plats averaged 72 per cent 

 taller than in checks. Examined 19 weeks after planting, applications made to 

 the seed were found to have increased the number of ear-bearing stalks to the 

 acre as follows: Oil of lemon, 1,159; carbolic acid, 945; formalin, 742; kero- 

 sene, 274. 



" The increase in root-lice in the field was seven-fold in 23 days — equal to 

 nearly 3 millions to 1 between April 1 and October 1. 



" In a small special test, made by planting a few hills of corn close around 

 nests of ants in the field, kerosene and carbolic acid kept the insects away from 

 the corn, but oil of lemon, formalin, and several other substances tested were 

 without effect." 



The precautionary measures recommended include a short rotation period in 

 corn, especially during relatively dry years; a deep, thorough, and repeated 

 stirring of old corn ground in fall or spring as a preparation for corn planting; 

 the maintenance and increase of the fertility of the soil ; and the use of 

 repellents. 



Habits and behavior of the cornfield ant, Lasius niger americanus, S. A. 

 FoKBES (lUiiwis »S7a. Bui. 131, pp. 31--'i5, fig. 1). — The author presents a detailed 

 account of the life history and habits of the so-called cornfield ant. 



While of great economic importance, due to its protection of the corn root- 

 aphis, this ant is by no means limited to cornfields, being abundant in all cul- 

 tivated land, in pastures and meadows, in dense forests, and various other 

 places. It is distributed over the whole of North America except the extreme 

 southern and southwestern portion, and is said by W. M. Wheeler to be the 

 most abundant of our ants. In the burrows of this ant are found various spe- 

 cies of root lice which it harbors, while in clover fields it is said to harbor mealy 

 bugs (Pscudococcus trifolii), which infest the roots of the clover plant. 



" Females and males hatching from pupm as winged ants in the underground 

 nests from June to October, swarm out of their burrows as if by common con- 

 sent in August or September. . . . 



" The males perish before winter, and the scattered females gc into the 

 ground, each making for herself an oval or spherical cavit5% the beginning of a 

 new family home. Some of these buried females begin to lay eggs in summer 

 and fall — August 15 to November 10, as we have seen them — but others live 

 there alone until spring, depositing their first eggs, according to our observa- 

 tions, from the first to the middle of May, and continuing to lay additional 

 eggs, a few at a time, until September. The minute, maggotlike, footless, and 

 helpless larvte begin to hatch from these eggs in June, and this hatching process 

 may continue until October. . . . We have found the oldest larvse full grown and 

 beginning to pupate from the 12th to the 16th of June, and pupation continues, 

 of course, throughout the season, as larvre from the later eggs successively get 

 their growth. The first workers to emerge from the pupte in these small colonies 



