August, '13] DEW: FALL ARMY WORM 365 



the two present in the largest numbers being Polistes canadensis and 

 Pelopceus cementarius. 



Nine true parasites were bred, four being Dipterous and five Hymen- 

 opterous. Nemorea leucanice, a Tachinid, and Sarcophaga georgiana, 

 one of the Sarcophagid*, were the most common of the Diptera. 

 The parasitic wasps were of two families: Braconidse and Ichneu- 

 monidse, the most destructive species being Eniscopilus purgatus, a 

 large yellow Ichneumon fly. 



At various times during the season the following birds were observed 

 feeding upon the wofms, arranged in order of their effectiveness: — 

 quail, field larks, common crow, mocking bird and English sparrows. 

 Turkeys and chickens naturally fed on the worms near habitations. 

 Early in the season small green tree frogs would secrete themselves 

 in the bud of corn plants, capturing and feeding oA unsuspecting 

 moths which would be in hiding. 



Control — Two methods of artificial control were found to be effec- 

 tive, mechanical and arsenical. Nearly a hundred experiments 

 were conducted during the year with varying results. From these 

 experiments the following conclusions can be drawn. 



First. A light shallow cultivation with either harrow or sweep 

 during the period of pupation will turn up from 10 per cent to 50 per 

 cent of the pupse. Ordinary summer heat at the surface of the ground 

 (120°F.) will kill the pupae in 20 to 30 minutes. 



Second. When the larvse assume the army habit of travel, rolling 

 with a heavy roller is ineffective except on hard ground. A heavy 

 log, dragged up and down in a furrow, in the path of the advance is 

 effective. 



Third. Arsenical Control. — Arsenate of lead, powdered, used at 

 the rate of 1^ pounds to 50 gallons of water was effective when applied 

 to plants so that larvaj would reach it. Arsenite of zinc used at the 

 rate of 1 pound to 50 gallons of water was also effective. When an 

 "ortho" Arsenate of Lead was used, there was no injury to any of 

 the food plants. Acid or 'meta" arsenates of lead gave burning 

 in some cases unless lime was added. Arsenical control was obtained 

 in young corn, only when the spray solution was forced into the bud. 

 Dusting of the poisons was not effective except on plants having a 

 broad lateral leaf surface as cotton, cowpeas, etc. 



Poison bait was ineffective in the majority of cases. Early in the 

 season when the fields were clean of grass and weeds and the larvse 

 spent the day in the soil, coming up at night to feed, the poison bran 

 mash killed large numbers when placed at the base of young corn 

 or cotton plants. 



Fourth. Moths can be trapped at lights from dusk to 11 o'clock 



