264 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 12 



were available and a considerable number of unnamed species. Each 

 of these species could easily be separated from either of the species 

 of Diatrcca but genus characters are hard to find, owing to the great 

 differences between some of the species, which seemed greater than 

 those between certain of the species and Diatrcea. In addition to the 

 characters given in the key, there are certain cuticular markings, which 

 may indicate sensory pores, that are always found in Crambus and 

 never in Diatraea. On the chitinized area in front of the thoracic 

 spiracle bearing the setse, all Crambus species have certain markings, 

 sometimes dark as in Fig. 12, no. 15, or at other times light, and some- 

 what transparent in appearance. Nearly all the species examined had 

 the darkly chitinized spot caudad of the spiracle on the proleg-bearing 

 segments much as those in Pyrausta (Fig. 13, nos. 27, 28, s. p.). On 

 these same segments, and sometimes on others, a small circular or 

 oval area was always found mesad of setae I. Similar markings are 

 also found in Pyrausta (Fig. 13, nos. 27, 28), but always dark-colored; 

 while those in Crambus are generalh" pale. 



Pyraustinoo.—lii addition to the characters given in the key this 

 subfamily may be distinguished by the arrangement of setae on the 

 tenth abdominal segment (Fig. 12, no. 23), and the different arrange- 

 ment of the ocelli (Fig. 12, no. 22, 26). Specimens of the genus Phlyc- 

 tcenia, which sometimes bores into stalks of celery, have not yet come 

 to hand, so this genus is reluctantly omitted. Diaphania nitidalis, the 

 pickle worm, and other species of the genus may easily be separated by 

 means of the key and Fig. 12, nos. 20-22. Out of six species of Pyrausta 

 examined, four of them namely — nuhilalis, penitalis, illihalis and 

 futilalis — only two seem very closely related, P. nubilaUs, the European 

 corn borer, and P. penitalis, a borer in Polygonum and other weeds. 

 Specimens from the lUinois State Natural History Survey labeled P. 

 nelumbialis, now a synonym for penitalis, do not resemble other material 

 of this species. They are considerably larger, fully one-third longer, 

 with much finer skin sculpturing, the spiracles more than twice as 

 large, and no trace of certain minute setae found on both penitalis and 

 nubilalis. This species varied from other species studied by the 

 characteristic skin sculpturing shown in Fig. 13, nos. 33 and 34. This 

 is considerably coarser in penitalis. The two species, penitalis and 

 nubilalis, are so closely related that they are very difficult to separate. 

 Since penitalis occurs in the region infested by the corn borer, and 

 also infests corn, it is important to be able to separate them. 



One of the easiest characters is the chitinized shield of the tenth 

 abdominal segment, which is usually truncate along the anterior 

 margin in penitalis, as in Fig. 13, no. 32, and with a rounded projection 

 at thecephalo-lateral angle but this character is not reliable, since many 



