CASTNIIDAE. 
By Dr. A. Seitz. 
5 
1. Family: Castniidae. 
We have placed this peculiar group at the head of the moths, not because we consider it the most 
highly organised or specialised family, but because its insertion in any other place would doubtless cause those 
objections to be raised to which expression has always been given when the Castniids have been associated 
with some other family. Undoubtedly the Castniidae are a highly organised and recent group; that is evident 
from their bionomics. In their life-histories and habits they are so closely associated with the most modern 
plants and animals that it is difficult to understand how anyone can regard them as very slightly modified 
descendants of some already extinct or vanishing group of Lepidoptera. They can only be considered as an¬ 
cestral inasmuch as their separation from the parent stock must have taken place at an early date, viz., when 
the distinction between butterflies and moths had not yet assumed the high degree of difference it has today. 
But they have adapted themselves to the present stage of evolution almost more than any other group. Their 
dress is often borrowed from undoubtedly recent groups of insects, the species of which are partly still 
in the process of evolution, i. e. from Danaids, Nymphalicls, etc. The moth derives its nourishment 
from flowers which belong to the very latest developments of the flora, the larva feeding in semiparasitic or 
even cultivated plants. The Castniids are pronounced diurnals, the moths being most active in the brightest 
sunshine. As regards the senses, that of sight is most strongly developed, and the whole bearing of the insects 
shows distinctly that this sense alone is sufficient to enable them to carry out all the functions of life. They 
copulate by day, and are quarrelsome on the one handwhile on the other given to playing together. They 
have an exact knowledge of locality, returning regularly to the places where they rest or feed, frequenting es¬ 
pecially white or bright red flowers. They are untiring and adroit fliers, being undoubtedly superior on the wing 
to the other Lepidoptera which visit the flight-places. 
The Castnias usually begin to swarm at about 10 o’clock, when the rays of the tropical are already 
uncomfortably hot, and show a preference for the honey of the blossoms of flowering trees. They rush wildly 
along, often from a considerable height, and by the violent impact of their hard body and with the sharp 
spurs on their long and stout legs drive away all small Diptera, Hymenoptera, and even Lepidoptera occupying the 
cluster or spray of flowers. The small wasps and especially Syntomids, which are nearly always found on such 
tree-blossoms, are simply knocked off, and the Castnia runs, buzzes and springs from flower to flower, dipping 
its strong proboscis rapidly into one corolla after another. They are most admirably adapted for fertilising 
flowers, and in spite of the smooth but very coarse scaling specimens are often met with which are entirely 
covered with pollen and therefore coloured according to their favourite flower. 
After 11 a. m. the Castnias usually seem to be satiated and to have also slaked their thirst, and begin the 
business of propagation. For this purpose they select a place of vantage, any projecting branch being suitable; 
preferably they sit on the highest twig of dry leafless bushes, like the European dragon-fly Libellula depressa. 
I actually attracted these moths by attaching dry branches on to the tops of bushes so that the bare twigs 
projected well into the air. Species like C. my g don, decussata and amyous are often also seen fluttering around 
the heaps of faggots piled up when the ground is being cleared. From this look-out the male keeps watch so at¬ 
tentively that it is difficult to approach it. Only occasionally I succeeded in getting so close to specimens of 
larger species, such as C. schreibersi and fonscolombe , that I could observe them minutely. They keep their 
wings folded in roof-shape, sit with the anterior portion of the body slightly raised, and when flying off bounce 
into the air, probably making use of the elastic tibial spurs. I was able to observe that they turned their 
head slightly towards humming-birds, etc., flying past them, as does a mantis or dragon-fly; their long thin neck 
enabling them to make this movement so unusual in Lepidoptera. This observation supports my opinion that 
in the preliminaries to copulation the sense of sight comes into play almost exclusively. The peculiar knotted 
antennae do not seem to be used until a later stage in the mutual approaching has been reached. The male Castnia 
rushes with wild and overpowering impetuosity at every insect remotely resembling itself. I once saw P. atym- 
nius fight the very strong Ageronia am/phinome and molest the latter until they left the spot, an open 
