844 
SPHINGIDAE. General Topics. By Dr. A. Seitz. 
special process the poison is eliminated from the tapioca-flour which is to be found on every Brazilian dinner- 
table and especially on that of the poorer colonists). Thus the larva appears to be safe bere, too, and therefore 
sits openly on the green food-plant as a very conspicuous object. 
What bright colours American Sphingid larvae may assume, if they intend to display the warning 
colouring at great distances, is most obviously shown by the gigantic lepidopteron Pseudosphinx tetrio, the 
enormous larva of which — the largest I have ever seen *) — is black with yellow transverse rings, and rusty 
or brownish-red at both its ends. The effect of this very bright colouring is still more increased by the frequent 
clustering together of the larvae of Ps. tetrio, which behaviour is quite uncommon for Sphingid larvae. If, 
however, isolated larvae have settled on the bark of a ficus-tree, basking in the sunshine, they try to attract 
attention by “nervous convulsions”, as Miles Moss writes; this is an evident proof that they expect more 
safety from their being recognized than from their keeping in hiding. x4s the leaves and stalks of the figs 
contain a milky sap which has an inflammatory effect upon the mucous membranes, the immunity of the larvae 
from enemies may be due to the after-effect of the chyles. It must, however, be mentioned here that another 
explanation is possible; a resemblance between the Sphingid larvae and those of other families, which is hard 
to explain, does not exist in the whole world; the resemblance of leaf-imitating green larvae of all groups of 
lepidoptera, as between certain Sphingidae, Endromis- larvae, some Noctuae, or the thoracal eye and hornlet 
between Bombyx, is a matter of course by way of natural convergency. A case quite unparalleled in any 
other fauna, however, is the double of Pseudosphinx tetrio occurring in another lepidopteral family, i. e. 
Arsenura Cassandra which shows an exact image of the uncommonly coloured larva being likewise black with 
yellow rings and coloured red at both its ends. 
In most of the Sphingid larvae the caudal horn has the relatively greatest length on its emerging 
from the egg, becoming shorter as the larva grows older and finally disappearing altogether in some larvae. 
In the neotropical region, however, some larvae (Isognathus) preserve the (above-mentioned) uncommon length 
of their caudal horn until the last moult. Moreover, wo notice the existence of 3 caudal horns in the early stage 
of Isognathus, since beside the usual one another pair of long stings rise on the anal plate. These paired 
stings are sometimes preserved until the third moult. 
If our presumption that the Sphingidae — geologically spoken — belong to the Moths having only 
differentiated in recent periods, is correct, we cannot wonder at most of the larvae feeding on the more recent 
vegetable families. In dealing with the Sphinges from other faunae we have mentioned the genus Leucophlebia 
the larvae of which feed on grasses, thus on Monocotyledons. I know of no similar example in the American 
fauna. Mostly living on trees, they exhibit a frequently extensive versatility in choosing their food-plant 
without denying a marked predilection for certain kinds of plants. In the same way as our Sphinx ligustri 
shows a distinct inclination for syringes, ligustrum and ashtrees and, besides, is also to be found on a great 
number of inland and foreign ornamental shrubs, many of the otherwise polyphagous Sphingidae of America 
are especially attracted by a favourite family; thus for instance the Protoparce (corresponding in some measure 
to the palaearctic Acherontia) prefer the Solaneae, the Herse the Convolvulaceae, the Protambulyx the Ana- 
cardiaceae, the Cocytius the Anonaceae, the Pholus the Ampelideae, the Xylophones the Rubiaceae, etc. 
It is quite obvious that poisonous substances of feeding herbs which are still effectively contained 
in the undigested or half digested food of the larva must protect the larva from the persecutions of many 
enemies. It is a different question, however, whether these substances can be preserved during the pupal 
stage by the process of histolysis to such an extent that their protection even extends to the imago-stage. In 
Vol. X, p. 354, we have expressed the opinion that such cases are not improbable, yet we are induced to 
presume that the complete transposition of the organs and tissues generally also destroys this protective 
effect of the poisons of the food-plants. In fact, this seems to be the rule, and in districts of our earth abounding 
in Sphinges, particularly in the neotropical countries, most of the Sphingidae are choice delicacies for all 
kinds of enemies. When the Sphingidae come to the arc-lamps, they find them already encircled by crowds 
of hungry bats which snatch away the approaching lepidoptera with an audible crack. On the panes of the lanterns 
there are large and small geckos snatching fugitive Sphingidae even when they swiftly glide or run across the 
pane. The worst enemies, however, are the gigantic toads, occurring in immense numbers in the neotropical 
region, which most greedily and gluttonously swallow throughout the year whatever drops to the ground 
around the lanterns attracting the lepidoptera. The Sphinges are even snatched away from flowers by birds 
or small mammals; cats jump after them, and the day-flying species are exposed to the persecutions of the 
widely distributed tyrant-birds (Tyrannidae) among which the Saurophagus, having become a characteristic 
*) More than 15 cm long, 3 cm thick, and 0 or 7 cm in circumference. 
