142 



THE AMERICAN ENTOMOLOGIST. 



characters of Pronuba, it nevertheless so 

 closely resembles it in general appearance 

 that upon studying its characters we 

 marked it in our cabinet with the name 

 with which it is here christened. In passing 

 through Dallas, Texas, in July 1879, 

 we stopped over to make a call on Mr. 

 Jacob Boll, having learned that he had 

 also bred what he considered to be Pronuba 

 from the flower-stems of Y . riipicola, and 

 we at once saw that the insect which he 

 had so bred was this Prodoxus. Before 

 the Entomological Club of the American 

 Association for the Advancement of Science, 

 at its meeting in Saratoga last August, we 

 gave a brief account of this Prodoxus, 

 showing how it differs from Pronuba in 

 the genitalia of the male ; in wanting the 

 characteristic maxillary tentacle of the fe- 

 male ; in inclining to maculation ; in the 

 larva having no legs ; in the characters of 

 the chrysalis, and in habit. We also ven- 

 tured the opinion that its existence ac- 

 counted for various experiences that led 

 Messrs Boll and Chambers to certain un- 

 warranted conclusions regarding Pronuba. 

 In a paper on the fertilization of Yucca, 

 read before section B, at the same meeting 

 of the Association, Mr. Thomas Meehan, 

 editor of the Gardeners' Monthly, gave 

 some experience with the fructification of 

 Yucca- angustifolia, endeavoring to show 

 that Pronuba is always abundant in the 

 flowers of this species of Yucca, which 

 blooms two or three weeks earlier than Y. 

 filamentosa, but that notwithstanding the 

 presence oi Pronuba the former plant never 

 produced fruit unless he himself artificially 

 pollinized it. We then made the point that 

 the moths seen by Mr. Meehan upon the 

 flowers of Yticca angustifolia were probably 

 this Prodoxus, in which event the inference 

 which Mr. Meehan drew from his facts, 

 namely, that because Pronuba did not 

 pollinize Y. angustifolia, therefore it did 

 not poUinize F./Zi/OTc/zA;™, would fall to 

 the ground, as would also the statements 

 in the following paragraph which we ([uote 

 from his paper : 



Pronuba yuccasella. the Yucca Moth, has for 

 years abounded on my flowers of the Yucca fil- 



amentosa. It has not been known to visit any 

 other plant than Yucca. Yucca angustifolia be- 

 gins to tiower from three to two weeks and its 

 blossoming is all over before Yucca filamentosa 

 begins to open. The facts now adduced show 

 that the moths exist weeks before the flowers 

 bloom with which they have been so intimately 

 connected, feeding of course on other flowers, 

 and would perhaps make use of other fruits as 

 depositaries for their eggs if Yucca should not 

 exist. At any rate the facts weaken any belief 

 we may have that the Yucca and Yucca Moth, 

 through the long ages, have become mutually 

 adapted to each other through a fancied mutual 

 benefit. 



We recently learned from Mr. Meehan 

 that he had discovered and sent to Dr. 

 Hagen, of Cambridge, what the latter con- 

 sidered a Coleopterous larva, boring in 

 the flower-stem of Yucca, and we at once 

 inferred that this might possibly be the 

 same larva with which we are now dealing, 

 its presence in Mr. Meehan's plants giving 

 fresh warrant for the explanation which 

 we offered of his facts presented last 

 autumn. Dr. Hagen has not been willing 

 to favor us with a specmien of said larva, 

 but informed us recently that it had trans- 

 formed and proved to be not Coleopte- 

 rous. 



We have long been familiar with the 

 facts brought forward by Mr. Meehan as 

 to the non-seeding of Yucca angustifolia, 

 and in a paper read before the St. Louis 

 .\cademy of Science (vol. iii, p. 570), thus 

 alluded to them : 



An interesting fact connected with Yucca pol- 

 lination came to my notice in the summer of 1876.* J 

 I have elsewhere shown that the /';v)«7(/w larvaH 1 

 as it lies in the cocoon underground, is not sus-* ■ 

 ceptible to the forcing influences that hasten the 

 development of most other insects. The moths 

 usually issue in St. Louis too late to pollinize 

 the flowers of Yucca angustifolia. This species 

 blooms from two to three weeks earlier than 

 Y. filamentosa, which, with its varieties, is most 

 commonly cultivated. As a consequence, the 

 former very rarely produces seed. One of the 

 rare occasions on which it did so was in the j-ear 

 stated, in the garden of Dr. Engelmann. All the 

 early flowers at the base of the raceme fell infertile, 

 but a few of the very latest at the apex were fruc- 

 tified, and, as the subsequent discovery of the 

 Pronuba larva in the capsules proved, they had 

 been duly visited by the moth. 



It was undoubtedly this Prodoxus which 

 caused Mr. V. T. Chambers to assert that! 

 Pronuba yuccasella was sometimes spotted,! 

 and which led us {loc. cit.) to make the fol-f 

 lowing criticism of his statement : 



