SPHINGIDAE. Genera] Topics. By Dr. A. Seitz. 
843 
but like a sphinx holds up its front end which is marked with a rather queer lateral eye not exactly imitating 
a snake, drawing its head completely in, instead of stretching it out as Leucorhampha does. A larva very 
similar to this is that of the genus Oryba. The larva of this bulky lepidopteron reaches the 4 or 5 fold volume 
of the preceding ones and, owing to its bulkiness, it has an effect entirely different from that of the slender 
Leucorhampha and Madoryx. The 5 foremost segments are transformed into a large mammalian head. The 
4th segment is widely thickened laterally; a kind of rat’s head with a crooked bridge of the nose and a very 
inflated cheek exhibits — at the anterior edge of the third segment of the larva — an angry-looking eye 
turned downward; its look has nothing to do with the ominous look of a snake, but it recalls the eye of the 
“Gamba” (Didelphys), i. e. the opossum being extremely dangerous to all the small living beings in America. 
This opossum is dreaded and shunned by all creatures — including man — in South America, on account of its 
fatal bites, its repulsive, half-naked exterior, and its horrible smell. No disguise more effective against small 
predatory animals could be fancied in the neotropical region. 
The attempts to intimidate aggressive enemies may, however, sometines be of quite different kinds. 
The anal horn which the larvae of the above-quoted genera lose before their pupation has grown in some 
species to a sting of 7 and more cm length, which is threateningly moved, though it. is entirely inoffensive. 
The larvae of Isognatus while creeping never keep this tail-appendage — which is similar to the sting of a 
Sirex — quiet, but move it constantly up and down in a threatening and evidently automatic way, by which 
they woidd betray themselves at great distances to any person in search of them, if this were not already 
effected by their very bright exterior with its white, black and reddish longitudinal stripes. Here we may 
suppose that the sting is used against parasites, which, on settling on the larva, are pushed away with the anal 
thread which extends across the whole dorsum. The larva of Isognatus living on leaves allied with strophant, 
oleander and other strong poisons (Apocynaceae) needs just as little protection against insectivorous verte¬ 
brate animals as the milk-weed larva of Celerio euphorbiae; it is even likewise interested — as the equally poi¬ 
sonous larva of Cel. nicaea — in not being overlooked or mistaken; it has no frightening or warning colour, 
and as the Tachinae and Ichneumonidae are known to disregard warnings, they are whisked down from the 
larva’s body by its extremely long tail-appendage. This warning colour and its effect form an interesting parallel 
to those of our European species of Celerio. In Goyaz and Araguary (Minas) I often found the extremely 
variegated, longitudinally striped larva of a species of Isognathus from the Is. mossi- group running up and 
down small poisonous trees of Apocynaceae in the hot sunshine, whereas the quite similar though not quite 
so variegated larva of Isognathus allamandae Clark living on the less injurious (even edible) Allamanda cathar- 
thica, according to Moss’ observations, keeps hidden in the roots of its food-plant in the daylight. Thus it 
acts exactly like the Celerio of which the glaringly coloured poison-feeders euphorbiae and nicaea are seen by 
day moving agilely about on the food-plant, whilst the larvae of C. gallii or C. vespertilio living on unpoisonous 
plants (Galium, Epilobium) hide their less variegated and inconspicuous bodies during the day, or even, as 
the C. hippophaes living on the unpoisonous Hippophae, adapts itself to the food-plant in the same excellent 
way, not betraying itself by any movement in daytime, as we have found it in the best adapted Sphingid 
larvae, such as Marumba quercus, Amorpha populi etc. 
Whilst the green Sphingid larvae of the other continents — but also most of them in America — copy 
ribs of leaves by means of lateral oblique stripes, we know American Sphingidae the larvae of which have 
so excellently adapted themselves to their food-plant that the insect has become quite unrecognizable owing 
to the extreme plastic transformation of its larval shape; and even to a greater extent than in the development 
of red dorsal protuberances copying flower-buds of Artemisia exhibited in the larvae of palaearctic Cucullia. 
The larva of Erinnyis lassauxi Bsd. has been entirely transformed into an exact reproduction of a flower- 
stalk of the food-plant, an Asclepidea called “Angelica doar”. These flower-stalks, on the coral having fallen 
off, represent themselves to the eye as a greenish stalk wound like a worm, the ends of which exhibit the 
growing placentae with two white pads each representing the dried milk of Asclepias. This peculiar formation 
has been imitated by a strange bend of the head-end of the larva, on which, above on the 3rd segment, the 
place of origin of the fallen blossom is designed and the poisonous milk of Asclepias imitated by two white 
guttiform protuberances. This marking is to be regarded as a distinct morphological violence, especially 
since the larvae of the closely allied species of Erinnyis, E. alope etc., do not show any formation out of which 
such a transformation might easily develop: alope has an almost black, cornigerous larva of the general Sphingid 
shape, being in no way adapted to its food-plant; its commonest food-plant is the melon-tree, Carica papaya, 
a Caricacea allied to the poisonous passion-flowers. The fruits of this tree may be eaten, but the milky juice 
of the leaves contains the very poisonous Papaine which instantly curdles fresh milk and presumably also 
other alkaline substances of the animal organism and softens the fibrous tissue of the animal body so effi¬ 
ciently that the Indians wrap up raw meat in the leaves of the melon-tree to make it delicate and to loosen 
the fibre-bundles from each other. Another food-plant of the larva of Erinnyis alope is the Cassawa shrub, 
Jatropha manihot, which supplies the eatable tapioca, but which itself represents a strong poison; (by a 
