3(11 



tln' Y lice. I it is not easily detectt'd. Tlic uiuU'r suifjices, however, are 

 dusky, ai»<l offset in flight the whiteness of the rest of the body, so as 

 to render the species somewhat diflicult of detection whiU^. flitting fr<nn 

 ])hint to plant. The male sliows no very maiked peculiarities to distiu- 

 guish him from the other members of the family, the most noticeable 

 being, perhaps, the prominence of the exposed i>arts of the genitalia. 

 The female, however, shows some remarkable structural pecailiarities 

 (Fig. 59), which admirably adapt her for the functions she has to per- 

 form, for she must fertilize the i)lant, since her larvje feed upou the 

 seeds. 



Now, if 1 should ask any well-informed entomologist what are the 

 characteristics of the Lepidoi)terous moth in the imago state, he would 

 unhesitatingly answer: The lack of all prehensile organs, and a coiled 

 tongue capable of sucking li(piids. If, again, I should ask what distin- 

 guishes the Lepidoptera from, say, the Hymenoptera, in the methods 

 of oviposition, he would answer that the Lepidoptera lay eggs possess 

 ing, it is true, an infinite diversity of form, but usually attached exter- 

 nally to some part of the food-plant of the species, while theHjanenop- 

 teia, as a rule, secrete theirs, and are furnished with either a puncturing, 

 boring, or sawing instrument lor that purpose. The generalization 

 would be entirely Justified, though there are many curious exceptions 

 to it, especially in the very group Tineina to which our Yucca Moth 

 belongs. It is, however, necessary to state these general truths in order 

 to convey a just idea of the exceptional nature of the two organs to 

 which I wish to draw your attention. The first is a ])air of maxillary 

 tentacles which are prehensile and spinous on their under surface. 

 They are peculiar to the genus Pronuba and exist in no other genus of 

 the many thousands of butterflies and moths.* The other organ is the 

 ovipositor, which, instead of being a simple opening, as typically found 

 in Lepidoptera, is here modified into a complex combination of lance 

 and saw. Ordinarily it is withdrawn and hidden, but when in action 

 is projected far beyond the tip of the abdomen, and is then seen to con- 

 sist of two princii)al parts, the basal part being imbricato-grauulate, 

 /. c, having a delicate, tile-like structure, the terminal part being smooth, 

 but having iiear the end a dorsal serrate chitinous wing and a still more 

 strongly toothed corneous ti}). The internal structure is seen to consist 

 of two stout rods extending along the thin walls to the very tip, and of 

 a ventral canal or passage-way for the delicate oviduct, which is silk 

 like and elastic and may be extruded for a great length from an outlet 

 near the end of the ovipositor. This oviduct is smooth basally, but 

 armed along its terminal third with retrorse hairs, increasing somewhat 

 in numbers and strength toward the tip, around which they are almost 

 spinous. At first sight these would seem to be out of place and to ini 



^ There are over 12,000 described species of Lepidoptera from Europe and America, 

 and those from other ])arts of the world will double this number. Nearly as man,^ 

 more remain, jterhaps, to be described. 



