20 
ZYGAENLDAE. General Topics. By Dr. A. Seitz. 
lizards which he had accustomed to being fed with edible insects, whereupon they greedily snapped at them, 
but instantly tore them again out of their mouths with their forefeet and then rubbed their mouths on 
the stones. The sap of the Zygaena therefore apparently possesses corrosive, burning or at least most 
obnoxious qualities. It is yellow, oily and has a smell like that of beetles from the genus Coccinella , though 
somewhat more caustic. 
This preservative, an obnoxious quality of the blood-sap, probably increased yet by glandular secretions 
is particularly found in the Zygaeninae ; as mentioned above, it is replaced by mimicry in the Chalcosiinae, 
though not all of them are mimetic; that some of them, particularly rnanv Chalcosia themselves, are pursued, 
is already obvious from their flight which, whilst in the protected Zutulba, Orna etc. it is quite steady and 
rectilinear, in the pursued species is oscillating and dancing, a motion noticed in all the unprotected Heterocera 
flying in daytime. It is the dancing motion and doubling which we know from the $($ of Orgyia antiqua, 
Lymantria dispar, Drepana cultraria, and Bupalus piniarius, and which renders it very difficult to the enemy, 
e. g. the bird, to snatch the insect, much more difficult than might be thought considering the nimbleness of 
swallows and similar enemies of insects. 
As to the larvae of the Ethiopian Zygaena very little is known. The larva of Zutulba namaqua 
is very much like those of many European Zygaena-, it is whitish with rosy tinted dorsal sides and longitudinal 
rows of thick black dots. The shape is entirely like that of wood-lice, somewhat recalling that of Lycaenid 
larvae; the food-plant, of which Fawcett figures a leaf*), is a Dicotyledon the name of which, however, 
he cannot state. 
Otherwise the food of the Zygaenid larvae known thus far almost invariably consists of highly developed 
plants which we are used to consider as belonging to the most modern epoch of creation, and this choice of 
the food-plant also makes us conclude that the Zygaenidae themselves represent a final shoot and not an 
old basal branch of the lepidopteral tribe. An uncommonly great number of these larvae live on cultivated 
plants, such as the vine ( Procris ), on tea ( Soritia angustipennis , Eterusia cingala ), on cockshead ( Zygaena carnio- 
lica) etc. Nearly all the European Zygaena live on species of Papilionaceae, i. e. that group of plants which, 
together with the Acaciae, Mimosae, Swartzieae, Caesalpineae represent the most highly developed shoot of 
the pedigree of plants; thus already the denominations {Zyg. trifolii, orobi, medicaginis, hedysari, coronillae, 
hippocrepulis, glycyrrhizxe, cytisi, astragali **) etc.) shows that the chief food of most of the species of Zygaena 
consists of Trifolieae. 
The presumption of the Zygaenid tribe not pertaining to an old epoch owing to their association with 
the most highly developed plants of the most modern creation, is still more corroborated by the habits of the 
imagines. As a rule, the phylogenetically oldest lepidoptera are nocturnal, as by far most of the Heterocera, 
many species among the oldest Rhopalocera ***), by far most of the Microlepidoptera etc. The Zygaenidae, 
however, are decidedly diurnal; they almost without exception fly during the hottest time of the day and 
in the warmest season of the year. We do not know a single winter-lepidopteron among this family; even 
the hibernating larvae go to their winter-camps at quite an uncommonly early period (in August); the larva 
of the only European Zygaenida living in the Alps [Zyg. exulans) is black, which colour is uncommon in its 
genus, but intensifies the warm effect of every ray of sunshine. Preferred habitats are sunny meadows and burning 
slopes of rocks, so that we have the impression that the Zygaenidae look for the warmth of the sun even there 
where genuine diurnal lepidoptera of other groups flee into the shade. Whether such intensely scorching heat 
of the sun, as is absolutely necessary for the genuine Zygaeninae, has ever existed in former epochs at all. is 
probably at least doubtful. 
The Zygaenidae frequently exhibit glossy metal-colours. Genera containing a great number of species 
( Pollanisus, Procris) are only composed of such colours. Already the nearest allies of our Zygaena being provided 
with dull black, red-spotted forewings exhibit in the more sunny districts of the Mediterranean coast a distinct 
metal lustre, such as the Z. stoechadis, medusa , occitanica etc. Among the Chalcosiinae there are species with 
a magnificent reflection, such as Erasmia pulchella , Pompelon marginata , Cyclosia midamia, Pidorus splendens 
etc. The South Asiatic Callizygaena ada combines on the forewing the bronze colours blue, yellow, and red. 
Presumably metallic colours are of frequent occurrence also in older groups of insects, but such an aggregation 
of glossy colours in one family, as in the Zygaenidae, does not argue in favour of old age. 
The geographical range of the Zygaenidae is likewise opposed to the presumption of old age for this 
lepidopteral branch. Old tribes of animals are generally presumed to be rather universally distributed. Even 
if some of the numerous submerged primitive bridges, which are supposed by various explorers to have existed 
in former epochs, should prove to be merely imaginary, yet the old animal families had decidedly more chances 
*) Transact. Zoolog. Soc. London 15, pi. 49. 
**) This of course refers only to those names derived from the food-plant of the larvae, not to Zyg. cedri, whose larvae 
do not feed on cedars, but whose imagines are particularly common on the Atlas mountains studded with cedars; to Z. scabiosae 
whose imagines are fond of resting on Scabiosae, whereas the larva lives on clover etc. 
***) Among the Rhopalocera feeding on monocotyledons the Brassolidae (larval food: palms), Amathusia, Zeuxidia, 
Thaumantis, Discophora (food: bamboo), most of the Lethe (Lethe sikelis begins to swarm at 8)4 p. m.; food: dwarf-bamboo); 
besides many Hesperids, such as Erionota thrax (food: Musa), species of Parnara (food: rice, palms) etc. 
