-s 



76 ILLINOIS BIOLOGICAL MONOGRAPHS [76 



a. The three caudodorsal ocelli forming a triangle with an acute angle 

 at the second ocellus (Fig. 77) ; seta kappa on metathorax at least 

 two and one-half times as far from eta as from theta.* 

 b. Vertical triangle longer than wide, touching adfrontals. 



Vespamima 

 bb. Vertical triangle broadly rounded, wider than long, usually not 

 touching adfrontals. 

 c. Crochets not more than nine in number, large and thick; setae 

 large and distinct. Parharmonia 



cc. Crochets usually over ten in number, when fewer they are small 

 and slender; setae reduced, 

 d. Adfrontals uniform in width, sides straight or convex. 



Sanninoidea* 

 dd. Adfrontals strongly narrowed near frontal seta, margins sin- 

 uate, concave in part of their course. Aegeria 

 aa. The three caudodorsal ocelli forming a triangle always with an 

 obtuse angle at the second ocellus (Fig. 75) ; seta kappa of meta- 

 thorax never more than twice as far from eta as from theta. 

 b. Spiracles of eighth abdominal segment located subdorsally, at least 

 six times as far apart as each is wide ; annulets distinct. 

 c. Crochets fifteen to eighteen in a row; adfrontal margins touch- 

 ing vertical triangle. Podosesia 

 cc. Crochets less than fifteen or more than eighteen in number; 

 adfrontals usually not touching vertical triangle. Memythrus 

 bb. Spiracles of segment 8 located on the dorsum, less than four times 

 as far apart as each is wide ; annulets indistinct ; setae very small. 



Melittia 



The following species were studied in arranging the above table : 



Vespamima sequoiae 



Parharmonia pini 



Sanninoidea exitiosa, S. opalescens 



Aegeria (Synanthedon) pictipes, A. rutilans, A. castaneae 



Podosesia syringae 



Memythrus polistiformis, M. rohinae, M. tricinctus, 31. hrillians 



Melittia satyriniformis 



In addition, Dyar in the paper referred to above describes the 

 following : 



*Each species of Sanninoidea differs somewhat from one or the other of the 

 two characters included in "a"; both characters must therefore be tried. 



