Alfalfa in Kansas. 



383 



just starting up after it has been cut, the poisoned bait should be sown 

 broadcast over the infested field in such a manner that the amount recom- 

 mended in the formula will cover about three acres. The worms do not eat 

 the poisoned mash so readily when it is dry, and for this reason it should 

 be scattered on the infested areas in the evening, because the worms work 

 mostly at night. If they are working on the alfalfa in the daytime, which 

 they will do on cloudy days, place it out in the morning or during the day 

 just as they are beginning to feed. 



As a barrier to their progress there is nothing better than a dust 

 furrow, made the same as the one for the chinch bug. If the weather is 

 cool and a fine dust can not be maintained it may be necessary to have 

 two or three furrows. Pestholes are made in the bottom of the furrows 

 at intervals of from ten to fifteen feet, where the caterpillars may collect 



in quantity as they travel up and down 

 the furrows seeking to escape. Here 

 they may be readily killed by pouring 

 kerosene upon them or by crushing 

 them. 



By a thorough spraying of the vege- 

 tation on which they are feeding with 

 an arsenical spray, large numbers may 

 be killed. If they are just moving into 

 a cornfield or an alfalfa field, a strip 

 should be thoroughly sprayed along the 

 edge of the field into which they are 

 moving. In making the sprays either 

 lead arsenate should be used at the rate 

 of three pounds to fifty gallons of water 

 or Paris green at the rate of one pound 

 to fifty gallons of water. In using Paris 

 green two pounds of stone lime should 

 be used to every pound of Paris green. 



To make a successful fight against these worms too much emphasis 

 can not be laid upon the necessity of beginning promptly. By a few 

 hour's delay acres of alfalfa and other crops may be sacrificed. 



FALL ARMY WORM. 



(Laphygma frugiperda S. and A.) 



Caterpillars much like the true army worm but distinguished by being 

 slightly more hairy, having four prominent black tubercles or spots 

 on each segment, and by the presence of a white inverted V on the 

 'forehead. (Fig. 330.) 



Habits and Life History. 



The fall army worms pass the winter in the pupal stage. The pupae 

 are shining light brown, about five-eighths of an inch in length, and are 

 found in cells from one-half to one and one-half inches below the surface 

 of the ground. The moths emerge in the spring and lay their eggs in 

 clusters of fifty or more on grasses. The eggs hatch in about ten days, 



FIG. 330. Fall army worm (La- 

 phygma frugiperda). a, Moth; &, fore 

 wing ; c, larva extended ; d, abdominal 

 segment of larva, side view; e,- pupa. 

 A.11 about natural size. (After Chittcn- 

 den, U. S. Dept. Agr.) 



