VI HETEROCERA PRODOXIDAE ERIOCEPHALIDAE 433 



maxillae (which in this sex are very remarkably formed)/ a con- 

 siderable mass of pollen, which she holds hj means of the peculiar 

 maxillary tentacles ; she then lays an egg in the pistil, usually 

 of some flower other than that from which she has gathered the 

 pollen ; and after she has accomplished this act she carefully 

 applies the pollen she had previously collected to the pistil, so 

 as to secure the fertilisation of the flower and the development 

 of the pod. 



The species of Frodoxus stand in a very peculiar relation 

 to Pronuha. They also live in Yuccas, and have habits similar 

 to those of Pronuha, with the important exception that, being 

 destitute of the requisite apparatus, they do not fertilise 

 the Yucca-flowers, and are thus dependent on Pronuha for 

 the steps being taken that are necessary for the rearing of the 

 progeny of the two kinds of moth. Hence the name of Yucca- 

 moth has been bestowed on Pronuha, and that of " liogus Yucca- 

 moth " on the Prodoxus. The Pronuha we figure is the largest 

 and most remarkable species of the genus and fertilises Yucca 

 hrevifolia ; the larva is destitute of abdominal feet, and in 

 the pupa the spines on the back that exist in nearly all pupae 

 that live in stems are developed to an extraordinary extent. 

 The Yuccas do not flower every year, and the Prodoxidae have a 

 corresponding uncertainty as to their periods of appearance, 

 passing sometimes a year or two longer than usual in the pupal 

 stage. 



Fam. 46. Eriocephalidae. — This family has recently been 

 proposed for some of the moths formerly included in the genus 

 Micropteryxr They are small, brilliant, metallic Insects, of 

 diurnal habits, but are very rarely seen on the wing, and it is 

 doubtful whether they can fly much. These little Insects are of 

 peculiar interest, inasmuch as they differ from the great majority 

 of the Lepidoptera in at least two very important points, viz. 

 the structure of the wings and of the mouth-parts. The mouth 

 shows that we may consider that the Lepidoptera belong to the 

 mandibulate Insects, although in .the great majority of them the 

 mandibles in the final instar are insignificant, fuuctionless 

 structures, or are entirely absent, and although the maxillae are 



1 The maxillary tentacle is considered by Prof. J. B. Smith to be a prolongation 

 of the stipes, cf. antca, p. 309 ; also Insect Life, v. 1893, p. 161. 

 '^ Chapman, Tr. ent. Soc. London, 1894, p. 366. 

 VOL. VI 2 F 



