28 ENTOMOLOGICAL NEWS. I Jan., 'l8 



aphid honey dew that they can hardly walk. This species 

 builds crater-shaped nests in moist spots, generally preferring 

 clay soil, probably because of its capacity for holding moisture. 

 The males and females remain in the nest over winter and take 

 their nuptial flight in the spring. The writer has captured 

 both forms in Ohio as early as March 27th. This form oc- 

 curs around the house, where it often gets into the pantry and 

 causes the housekeeper a great amount of trouble. 



P. parvula Emery. 



This form is smaller, more hairy, and of a darker color than 

 P. imparts. The workers inhabit the fields, where they often 

 build their nests under rocks. 



Genus Lasius Fabricius. 



1. Maxillary palpi six-jointed; general color deep brown. 



nigcr Linn., var. americanns Emery. 

 Maxillary palpi three-jointed (Subgenus Acanthomyops} , 2. 



2. Petiole low and broad when viewed from above; hairs of the body 



short latipes Walsh 



Petiole higher and narrower; abdomen with longer hairs 3. 



3. All but the last joint of the antennae broader than long, 



claviger Roger. 



All but the last joint of the antennae not broader than long; 

 posterior edge of each abdominal segment with a fringe of 

 long hairs inter jcctus Mayr. 



L. niger Linn., var. americanus Emery. 



This form is very common in the corn and cotton fields of 

 the State. Professor Forbes, of Illinois, has published several 

 interesting bulletins on this species' relation to the corn and 

 cotton root louse, Aphis maidi-radicis. It has been definitely . 

 proven that these ants are responsible for the spread of the 

 root louse. The ants are very abundant throughout the United 

 States, except the extreme southern and southwestern sections. 

 The workers have an abdomen with a pruinose appearance, 

 which when crushed gives off a strong formic acid odor. Prof. 

 W. A. Thomas, of South Carolina, has found that the cotton 

 root louse, to a large extent, may be controlled by shallow 

 plowing the growing cotton at frequent intervals, thus disor- 

 ganizing the ants. 



