LEPIDOPTERA 



645 



The members of the different subfamilies of this family differ so 

 greatly in appearance that it is not possible to give a general descrip- 

 tion that will serve to distinguish it ; a very large portion of the species 

 have a special look, due to their thin and ample hind wings with large 

 anal areas; it is necessary, however, to study structural characters to 

 find evidences of a common bond. 



The body is slender ; the head is prominent ; the ocelli are usually 

 present; the antenna are almost always simple, but frequently the 

 antennee of the male have a process on the scape or a notch and tuft 

 on the clavola; and the palpi are usually moderate in size or long; 

 but very often they project beak-like; for this reason the name 

 snout-moths is often applied to this family. 



Fig. 790. — Wings of Nomophila noctuella. Fig. 791. — Wings of Tlascala reductella. 



As a rule there are three anal veins in the hind wings and one in 

 the fore wings. The discal cell is always well-formed, but there is no 

 accessory cell. In most cases the pyralids can be recognized by the 

 fact that the subcosta and radius of the hind wings are separate along 

 the discal cell, but grown together for a short distance beyond the 

 cell, after which they are again separate (Fig. 790). In some genera 

 these two veins do not actually coalesce, but extend very near to- 

 gether for a short distance (Fig. 791). The two types, however, are 

 essentially the same. 



This is one of the larger families of the Lepidoptera ; nearly one 

 thousand species have been described from America north of Mexico 

 alone. The family is divided into many subfamilies, representatives 

 of fifteen of which are found in our fauna. The best known species, 

 those that have attracted attention on account of their economic 

 importance, belong to the subfamilies discussed below. 



