352 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 



able. We liave already mentioued (p. 17) an instance in which the 

 plowing up of a number of the pupae of this species was considered ab- 

 solute evidence of the underground hibernation of Aletia, and indeed 

 to separate the two species in this state requires a trained eye. In gen- 

 eral appearance the pux^a of rhexia is lighter in color and has a blunter 

 anal extremity than that of Aletia. The chief distinguishing character 

 can be readily seeu with a hand lens, and consists of two long, slender 

 thorns projecting from the anal end of the body and converging until 

 their points meet. 



The larva feeds upon Solanaceous plants, and we have bred it from 

 Solavum seigllnge and Physalis viscosa at Saint Louis, where the former 

 plant is very rare. A descrij^tion of the larva is given in Note 16. The 

 moth is smaller than Aletia, and has olivaceous front wings crossed by 

 three light bands, each relieved by a dark greenish shade on its outer 

 order 5 the hind wings are silvery white, slightly tipped with dusky. 



Drasteria erechtea (Cramer). 

 [Plate LXII, Fig. 5.] 



This common moth is indigenous to North America. It is found from 

 Hudson's Bay to the Gulf of Mexico, and west to California. In the 

 British Museum Catalogue it is stated that the Hudson's Bay specimens 

 are hardly more than half the size of those from New York, and Mr. 

 Grote [Canadian Entomologist^ YII, p. 48) states that while the California 

 specimens agree with the typical form from the East, they are larger. 

 There is also a seasonal difference in size, and we already remarked in 

 1869 {American Entomologist^ I, p. 206), ^^We have observed that the 

 spring brood of this insect are always several sizes smaller than the 

 autumnal brood, and at one time we supposed the two forms to belong- 

 to distinct species." We have since abundantly verified the fac^ of the 

 generally smaller size of the vernal as compared with the autumnal 

 forms, and it has been recognized also by others (see Packard, PapiJio^ 

 II, pp. 147-148). Eggs obtained by us from a large female, October 14, 

 1881, hatched October 31, and the moths issued from January 9 to April 

 30, 1882, all being of the smaller size. The colorational variation occurs 

 in all broods and is so great as to have given rise to some eight differ- 

 ent synonyms. 



While the larvae of this moth have never occurred in what may be 

 called injurious numbers, yet feeding as they do on grass and clover, 

 they occasion a constant drain upon forage crops. In one instance they 

 have l)een sent to us as feeding on Cottonwood [Colman'^s Rural World, 

 January 26, 1876). The adult is familiar to almost everyone who has 

 traversed a meadow as the little darting moth which often flies up be- 

 fore one, dropping a few yards away and concealing itself at ihe base 

 of some clump of grass. In the Northern States there are two annual 

 generations, and the insect hibernates as a pupa. In the middle lati- 



