56 ILLINOIS BIOLOGICAL MONOGRAPHS [56 



j. Crochets homoideous (Fig. 105) ; mesothorax 

 bearing two verrucae above Kappa group; lab- 

 rum with a deep, parallel-sided notch. 



NOCTUIDAE 

 jj. Crochets heteroideous (Fig. 100) ; mesothorax 

 usually bearing only one verruca above Kappa 

 group; verrucae conspicuous, altho without nu- 

 merous setae. PERICOPIDAE 

 hh. Spiracles small, circular (Fig. 104). 

 i. Head small, retractile; prolegs short. 



PYEOMORPHIDAB 

 ii. Head not retractile; prolegs long, slender, cylin- 

 drical (Fig. 95). PTEROPHORIDAE 

 dd. Crochets biordinal or triordinal (Figs. 102, 106). 



e. Setae of body either primary or tufted, never numerous and 

 secondary; several subprimaries present on venter or on 

 prolegs, sometimes rather numerous when anal prolegs are 

 wanting or ventral prolegs reduced in number (Fig. 63). 

 f. Crochets in a complete circle (Fig. 101). 



g. Alpha and beta of abdomen in the form of verrucae. 



( Scythris ) . YPONOMEUTID AE 



gg. Alpha and beta of abdomen single setae ; kappa and 



eta of abdomen adjacent. LACOSOMIDAE 



ff. Crochets in a mesoseries (Fig. 106) or pseudocircle (Fig. 



97). 



g. Suranal plate terminating in an acute process and anal 



prolegs wanting (Fig. 89) ; crochets in a pseudocircle. 



PLATYPTERYGIDAE 



gg. Suranal plate rounded caudad; anal prolegs present. 



h. Number of pairs of ventral prolegs four, all well 



developed. 



i. Kappa group on prothorax trisetose (Fig. 39) ; 



kappa and eta of abdomen adjacent. 



ETHMIIDAE 

 ii. Kappa group on prothorax bisetose (Fig. 43) ; 

 kappa and eta distant, at least on abdominal seg- 

 ments 4 to 8. 

 j. Prothorax and abdominal segment 8 with spira- 

 cles twice as large as those of other segments. 



EPIPLEMIDAE 



