Tineidae 
(6) Prodoxus cinereus Riley. 
This species is known to breed in the flower-stems of Yucca 
whipplei. The best way in which to set the species before the 
Fig. 261.— P. cinereus. a , larva; b, head and first thoracic 
joint; c, anal hooks; d , pupa; e, pupal shell protruding from 
stalk; f adult female; g, side view of clasper of adult male. All 
figures greatly enlarged. (After Riley, “ Insect Life,” Vol. V, 
p. 306.) 
reader seems to be to reproduce, as we have done, the figure 
given by the author of the species, in which its characteristic 
features are carefully depicted. It is found in California. 
Genus PRONUBA Riley 
(1) Pronuba yuccasella Riley. (The Yucca Moth.) 
No discovery in recent years has been more interesting to 
students of insect and plant life than that which was made in 
1872 by Professor Riley, of the intimate relationship which sub¬ 
sists between the beautiful plants, known as Yuccas, and the 
genus of moths to which the present species belongs. It has 
been ascertained that the fructification of the various species of 
Yucca is almost absolutely dependent upon the agency of the 
female moth ; and, strangely enough, it has also been ascer¬ 
tained that the pollenation of the flowers is not the result of 
mere accidental attrition of the wings and other organs of the insect 
when engaged in seeking for nectar in the flower and when en¬ 
gaged in laying her eggs, but that she deliberately collects the 
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