Pub. 4. I. 1930. 
HEPIALIDAE. General Topics. By Dr. A. Seitz. 
553 
24. Family: Hepialidae. 
In Vol. II (p. 433) it was stated by R. Peitzner that the Hepialidae sharply contrast with all the other 
macrolepidoptera and, united with the most primitive group of the microlepidoptera, form the division of the 
Jugatae having a frenular lobe instead of bristle. But they seem also in many other respects to be still more 
primitive than many of the most closely allied Micropierygiidae which, even with the addition of their allies, 
the Eriocraniidae, scarcely number more than 50—60 species known hitherto. We cannot decide here whether 
the Hepialidae are yet to be ranged below the Micropterygiidae, as Comstock’s view is, or according to Chap¬ 
man, above this group; we merely state that the Laciniatae (as the union of the two groups of Micropter ygiidae 
and Eriocraniidae is called) being the most closely allied to the Hepialidae, still exhibit parts of the mouth 
inducive of rather a biting than a sucking action which no more exists in the recent species, but which was 
formerly present, since the mandibles of many Laciniatae still exhibit a broad, dentate edge with a hinge that 
is apparently still used and only occurs in biting insects. 
This structure of the mouth of the Eriocraniidae is extremely similar to that of certain Neuroptera o, 
Odonatae which the Hepialidae also resemble in other respects. The most remarkable feature is the elongatedr 
dragonfly-like structure of the body and wings. The pro-, meso- and metathorax of the Hepialidae is even still 
less solidly jointed than in the dragonflies. The third thoracal segment is still cpiite independent and, by a 
waist-shapecl strangulation, it is so far removed from the mesothorax that the place where the hindwings are 
joined on is quite a distance from that of the hindwings on the mesothorax, thereby producing a gap between 
the bases of the two wings. Moreover, the different abdominal joints (most distinctly shown in the genus 
Hepialus itself) are frequently longer than they are broad, thus nearer the shape of the segments of Odonatae 
than those of the lepidoptera. Thereby the whole structure of the imago has remained much more like that 
of the larval shape than in the lepidoptera of any other group. 
A still more striking resemblance of the Hepialidae to the Odonatae is exhibited by the structure of the 
head. The entirely different, almost contrary habits of the two insect groups does not admit any clue for the 
explanation of this resemblance as being produced by convergency or as the adaptation to the same condition 
of the surroundings: as in Odonatae, the Hepialidae exhibit enormously enlarged eyes which, in Australian 
Gharagia, sometimes reach so far around the head that they are only separated above by a linear frontal streak, 
thus almost the same as in the dragonflies of the Aeschnid genus Gomphus. Besides, the antennae of the 
Gharagia are reduced to small, short, bristle-shaped thin threads, so that the formation of the head, abdomen, 
and wings is extraordinarily similar to that of ancestral insect forms. If we consider besides that the dragon¬ 
flies being heliophile rapacious insects show, as mentioned above, life-conditions entirely different from those 
of the dusk-loving, mouthless Hepialidae the imagines of which have a very short life and are quite lethargic 
with the exception of their flying time often amounting to scarcely half an hour, these resemblances can only 
be explained by very distant relationships of the two groups. Other resemblances of the Hepialidae lead to 
other families of the Neuroptera, to the Trichopteridae, Panorpidae or Hemerobiidae , and some authors regard 
the Eriocrania as the true intermediate links between the. Hepialidae and the Phryganidae. 
As all other ancient insect families, the Hepialidae are also distributed over the whole earth. The 
palaeontologically most ancient islands and continents, such as New Zealand and Australia, do not only 
exhibit a relatively great abundance of ancient Hepialidae, but the latter seem to have maintained themselves 
there particularly well and victoriously. Of the more than 250 Hepialid forms known 63 occur in the Ethiopian 
region, more than double this number in the American region, and upwards of 100 in the In do-Australian 
XIV 70 
