ZYGAENIDAE. General Topics. By Dr. A. Seitz. 
21 
of expansion than those having only developed in modern times. We notice, however, the range of the Zygaenid 
species confined to such a degree as is hardly known of any other family of lepidoptera. The genus Zygaena, 
of which more than 100 forms are distributed in the Mediterranean region, radiates with but one form into 
Eastern Asia, and of the almost 400 Asiatic Chalcosiinae not one reaches Europe. More quickly and sooner 
the Zygaeninae disappear towards the polar regions, being an inevitable consequence of their heliophily. But 
also the single forms for themselves exhibit a frequently uncommonly limited range. There are forms whose 
habitats do not extend beyond a certain mountain-slope; some only occur in certain valleys or they are confined 
to distinctly limited habitats. Their sudden disappearance at the place where the character of the country 
is in the least changed, proves them to be bound to local or climatic conditions which cannot have existed for 
a long time in the very same combination, so that it seems to be out of the question that forms of such great 
climatic dependency may have existed in foimer, quite different epochs in this sensitive form. 
The total impression gained from the different genera also argues in favour of the opinion that the 
present Zygaenidae are from the very latest epochs. The division of every single species into a great number 
of well distinguished subordinate forms and races *) makes it appear likely that the Zygaenidae are far from 
that fixedness generally attained by animal forms of a high phyletic age, being the consequence of infinitely 
long generations. Species, such as Cyclosia midamia, that have numerous well distinguished local races, i. e. 
that evidently are able to copy without difficulty the most advantageous model lepidopteron in any country, 
can impossibly be old. Even where there is no evident reason for the formation of races as mentioned above, 
as in Cyclosia pieridoides, in many European Zygaena etc., frequently a splitting into local races takes place 
as we find it to be in phyletically younger Rhopalocera, but never in older lepidoptera, in the microlepidoptera, 
Cossidae, Hepialidae, even scarcely in any of the other lepidoptera! group reckoned to the ,,Bombyces“ or 
,,Sphinges‘ ( in the old sense. 
The most striking argument in favour of the modern character of the Zygaenidae is their propensity 
for cross-breeding. Whilst we formerly took our proofs from the exterior, the great number of cross-breeds 
amongst various species of Zygaena shows us that the scent of the species inducing the couples to copulate 
is still so little differentiated that the insects find it more difficult to distinguish their single species than could 
be noticed with any other lepidopteral group. Among the immense number of Syntomid couples I was able 
to watch, I have never observed a cross-breed, whereas in the Zygaena it occurred several times. Standfuss 
even yielded larvae from erroneously copulated so that it is not out of the question that even a real 
imprecation takes place. Beside the equality of the scent of the species, an effective cross-breed also presupposes 
a certain homogeneousness of the genitals which are otherwise regarded as the best mark of distinction of 
species, the specifically very exact composition usually opposes a mechanic resistance to cross-breeding. 
Under such circumstances the separation of species in the different genera of Zygaenidae is often only 
to be considered as provisional. Those genera causing the greatest difficulties in this respect, such as Proc-ris 
and Pollanisus, apparently do not occur anymore in the Ethiopian Region. Of the former this seems to be 
certain, whereas of Pollanisus one species from West Africa was described by Holland. As this genus is 
reckoned to the Chalcosiinae, we had mentioned their occurrence in the Ethiopian Region in the Preface of 
Vol. XIII (p. 5); however, the author is apparently mistaken, since he seems te have had before him a Homo- 
phylotis (may-be catori) in establishing his Pollanisus obscurissimus. Our remark that of the Chalcosiinae but 
one single species occurs in the Ethiopian Region, would therefore have to be corrected. 
Finally, we beg to point out that a great many Zygaeninae are decided flower-insects, most preferably 
met with on Scabiosae, umbels, and above all on Thymus, Lavendula, Echium, Epilobium, Origanum and 
many Labiatae and Trifolieae. As also the variegated, scented blossoms abounding in honey are considered 
to be one of the modern achievements of our creation, this fondness for blossoms found in nearly all the Zygae¬ 
ninae and Chalcosiinae tells more in favour of the modern character of the family than for the assumption that 
they are to be regarded as an old relic **). 
Of the 5 divisions into which the Zygaenidae are split, 4 occur in the Ethiopian Region: the Himantop- 
terini (= Thymaridae auct.), the Phaudinae , Pompostolinae, Zygaeninae. 
*) We do not mean the excessive denominations for every accessory spot or abdominal ring, but only the real 
designations of races. 
**) Even those authors whose investigations are chiefly based upon anatomical marks, are forced to own the fact 
that the Zygaeninae rank very highly in the lepidopteral pedigree. In dealing with the modern systematic researches, Tutt 
says, speaking of Chapmann’s results: he states, that the Zygaenidae in many respects take a high place (Trans. Ent. Soc. 
Lond. 1895, p. 531). 
