Genus MEGATHYMUS, Riley
[a]Fig. 181.]—Megathymus yuccæ, ♁.
This genus comprises butterflies having very stout bodies, broad wings, strongly clubbed antennæ, very minute palpi. The caterpillars are wood-boring in their habits, living in the pith and underground roots of different species of Yucca. The life-history of the species represented in the cuts has been well described by the late Professor C.V. Riley, and the student who is curious to know more about this remarkable insect will do well to consult the "Eighth Annual Report of the State Entomologist of Missouri" (p. 169), or the "Transactions of the St. Louis Academy of Science" (vol. iii, p. 323), in which, with great learning, the author has patiently set forth what is known in reference to the insect.
[a]Fig. 182.]—Megathymus yuccæ: a, egg, magnified; b, egg from which larva has escaped; bb, bbb, unhatched eggs, natural size; c, newly hatched larva, magnified; cc, larva, natural size; d, head, enlarged to show the mouth-parts; e, maxillary palpi; f, antenna; g, labial palpi; h, spinneret.
The genus Megathymus is referred by some writers to the Castniidæ, a genus of day-flying moths, which seem to connect the moths with the butterflies; but the consideration of the anatomical structure of this insect makes such a reference impossible. The genus properly represents a subfamily of the Hesperiidæ, which might be named the Megathyminæ. The species represented in our cuts is Megathymus yuccæ, Boisduval and Leconte. There are a number of other species of Megathymus that are found in our Southern States, principally in Texas and Arizona. They are interesting insects, the life-history of which is, however, in many cases obscure, as yet.
[a]Fig. 183.]—Chrysalis of Megathymus yuccæ.