Tineidse 



annually a sum of money which is enough in amount at the 

 present time to pay the interest upon the national debt. 



Genus ADELA Latreille 



The moths of this genus are remarkable for the enormous 

 length of their antennae in proportion to their size. We have 

 represented one of the commoner species on Plate XLVIII, Fig. 

 45. It received the specific name bella at the hands of the late 

 Mr. V. T. Chambers. The base of the antennae is black, and the 

 extremity is white. This fact has prevented the photographer 

 from getting a full representation of the length of the organ in our 

 cut. This is much to be regretted, and the student must add in 

 his imagination to the antennas, as they are shown, a thread-like 

 extension, extending fully three eighths of an inch beyond the 

 apparent ending of the organs as depicted. The moths may be 

 found in shaded woods in June feeding upon the flowers of 

 Asclepias. 



Genus PRODOXUS Riley 



The relation of the insect world to the life of plants has been 

 the subject of a great deal of interesting inquiry in recent years. 

 It has been discovered that many genera and species depend for 

 their fructification and consequently for their continued preserva- 

 tion upon the agency of insects. Without the kind attention 

 which they receive from the tiny creatures of the air, they would 

 not produce seed, and the race would speedily become extinct. 

 One of the most beautiful illustrations of the interdependence of 

 the world of plants and the world of insects has been discovered 

 in the case of the Tineid genus Pronuba. This insect has be- 

 come specialized to a remarkable degree, as we shall have occa- 

 sion to show in speaking of it. In fact, without its agency the 

 pollenation of the plants belonging to the genus Yucca is never 

 accomplished. But, curiously enough, associated with it and 

 closely resembling it superficially is a genus of moths which does 

 not possess the power of pollenizing the Yucca, but which is 

 represented by many species the larvae of which feed in the stems 

 of the various species of Yucca. The Yucca plants depend for 

 the perpetuation of the species upon the moth Pronuba. The 

 moth Prodoxus depends upon the Yucca plants for life, and thus 



437 



