776 
AEGERIIDAE. General Topics. By Dr. A. Seitz. 
South-American Aegeriidae exhibit all their 6 legs provided with broad locks of hair disfiguring the lepidoptera 
altogether, if they project on the sides of the wings which are laid close across the abdomen. On being alarmed 
these insects do not fly off immediately, but run across the surface of the leaf almost like a spider and then 
hide underneath the leaf. Ghamaesphecia seitzi Pnglr., which is yet palaearctic, strikingly resembles one of 
the species of Zygaena, shunned by all the insectivora, and flies about singly among the great numbers of 
swarming Zygaena, so that I was completely deceived for a long time and took no notice of them whatever. 
It copies the Zygaena not only in flying, but it also rests on the stalks of milk-weed in a position never 
occurring in other Aegeriidae but especially in Zygaena, i. e. closely appressed to the stalk of the plant, with 
its head up. We can therefore only state that the general mimicry on the whole — not single features of it, 
as for instance the assimilation of the lepidoptera! wings to the hyaline wings of the Hymenoptera — is a family 
characteristic of the Aegeriidae. 
The first presupposition of so general a mimetic transformation is that the imitators can be eaten 
by their enemies, the second that they are not protected by interior saps. As a considerable number of Aegeriid 
larvae live in poisonous plants (especially Euphorbiaceae), it seems that the poisonous substance of the food- 
plant does not pass over to the imagines in these cases. This must be expressly stated here, because the 
members of other families have been observed to behave contrarily *). 
The larvae of the Aegeriidae are entirely endophyte. They partly live in wood, partly inside the stalks 
of plants, and are mostly monophagous or oligophagous. We know next to nothing about the early stages of 
the Indian and Australian species. As a number of elsewhere known larvae of Melittia live on Cucurbitaceae, 
it may be likely that also Indo-Australian members of this family are to be found on the stalks of such plants. 
A great many Aegeriid larvae live in hard wood, and some have been observed to be particularly fond of cancroid 
swellings of the bark, which may also be caused by them. The larvae are decidedly regressively transformed 
by their mostly boring habits; all the colouring, if ever such had existed originally, has been'replaced by a 
transparent bone-colour generally occurring in boring wood-worms or hidden maggots. The skin is smooth, 
glossy, the tiny tubercles studded with very short bristles are small or they may disappear nearly altogether 
{Melittia). The biting-organs are well developed according to the hard food and are partly real boring-tools, 
partly also adapted to softer food in those species which live in soft pith or inhabit the galls of other insects. 
The pupae are mostly very mobile; only two segments do not participate in the pushing motions by 
which the incects are able to move up and down in the bored passages. The various sheaths of the single members 
are only loosely joined together, so that on the discharge of the imago they are separated from each other in 
a similar way as in the Cossidae. 
The imagines are decidedly sun-animals with but very few exceptions, and mostly very fugitive. Very 
soon after the emergence they begin to swarm, and the AA very often execute the copulation, before the $2 
have developed their wings for flying. The flight itself is by no means uniform in the different species and 
frequently influenced by the mimicry. We have already stated in Vol. XIV that the Aegeriidae often imitate 
the flying habits of their models, as for instance the smaller or more slender forms copying Ichneuinonids often 
imitate the oscillating flight of their models, whereas the species imitating large buzzing Aculeatae move on 
clumsily and slowly, copying the flying-sound of their models. The smallest species exhibit a gnat-like haste, 
touching the leaves or the ground only for a few seconds’ rest and immediately vanishing again from the pursuer’s 
sight owing to their small size. 
The Aegeriidae distinctly prefer dry and often scorched places, but they also occur in luxuriant wood¬ 
land. Sunlit mountain-slopes are most frequented, but also hedges and bushes are often surrounded by the 
swarming Aegeriidae. Most of them are particularly fond of the honey of blossoms and flowers, and many 
favour only special blossoms. In sucking from the flowers most of the species hold their wings quiet, except 
those which copy incessantly buzzing Hymenoptera and must, for the sake of deception, behave in the same 
way. On being energetically pursued some drop into the grass and try to escape there, in doing which they 
suffer the loss of the hair and scales covering them. But also when they are captured, most of the species usually 
fly restlessly about in the net and are slightly injured thereby, and in the cyanide-glass they are in the habit 
of throwing themselves on their back and grinding off the thoracal vestiture which is often particularly 
important for the identification of the species. The legs are also extremely loosely dovetailed and 
*) We refer our readers to what has been said about the Sphingid genus Celerio in Vol. XIV, p. 355. Xot only 
do the brightly coloured and distantly visible larvae of this genus, living on the very poisonous Tithymalum, remain 
quietly settled on the food-plant in the day-time (as for instance Cel. nicaea), but also the many-coloured imagines often exhibit 
themselves quite openly, whereas the larva of the allied Cel. vespertilio living on unpoisonous plants hides during the day 
and its imago has changed the bright colour's of those parts of the body which are visible in repose for the protective 
rock-colour. 
