SYN'l'OMlDAE. Uy Dr. A. Seitz. 37 



8. Family: Syntomidae. 



Nearly always small moths, which very rarely attain nearly medium size, and have a rather stout 

 body, lanceolate forewing and very small hindwing, which sometimes appears to be a mere appendage to 

 the forewing. Head small, with convex and comparatively very broad frons, and scmiglobular eyes set 

 far apart. Antennae usually setiform, but occasionally pectinated, or in the wasp-like forms as thick as 

 the antennae of wasps. Tongue nearly always strongly developed, but sometimes aborted. Palpi very 

 short. Legs strong, the hindlegs especially often conspicuously modified in appearance by tufts of hair, 

 brushes, vivid marking and colouring. Tibiae with short spurs. Forewing rather narrow with the apex 

 slightly rounded and sometimes somewhat widened. The cell more than half the length of the forewing, 

 mostly very narrow at the base and broad and truncate at the apex. The submedian forked at the base. 

 Where the hindwing is strongly reduced, the venation is much simpHfied; cell small; frenuhnn present. 

 Abdomen often very stout in the females, so that these cannot fly if the wings are shortened at the same 

 time. The abdomen is frequently ringed and spotted with yellow and metallic colours. — Larva quite 

 unlike those of the preceding group, bearing crests of hair and often brushes and long tufts. The hairs 

 are generally placed on rows of short warts on the back, while anteriorly and posteriorly long tufts of 

 hair are directed foreward and backward respectively. Very often the larvae have extremely vivid colour- 

 ing, being snow}^ white, bright red, etc. Pupa usually short and stumpy, the segmental incisions very 

 deep, otherwise wathout special characteristic. It lies in a round, egg-shaped, tough cocoon, which some- 

 times resembles a small bird's-egg. 



-bf5* 



Nearly all the Syntomids are diurnal, often marked with bright metallic colours, and show a 

 golden gloss when on the wing. They nearly all frequent flowers, and are so fearless when sucking that 

 one can take them with the fingers. When disturbed they go off with a straight, whizzing flight, similar 

 to that of Zygaena, and settle in the grass or bushes, some on the underside of leaves. Many of these 

 moths closely resemble other insects, especially aculeate Hymenoptera and mimic their movements and 

 mode of flight. In several tropical species {Trichura) even the sting of an Hymenopteron is mimicked by 

 a peculiar hairy process at the apex of the abdomen. Those insects which most closely resemble wasps 

 have a peculiar waist-like constriction, the perfectly egg-shaped abdomen being connected with the thorax 

 by a thin stalk. The colouring of these mimetic species is hke that of the model. In the Old World 

 where the poisonous wasps belong to the genera Vespa, Eumenes, Pollistes and Odynerus, and often have 

 yellow-ringed bodies, many Sj'ntomids are also ringed with black and yellow; while in tropical America, 

 where the best-armed Hymenoptera, belonging to the Pompilid genus Pepsis, are blue in colour, the 

 Syntomids are often also uniformly blue-black. In fact, one may say that there is no very poisonous 

 genus of Hymenoptera with an abundance of species which is not imitated by some Sj^ntomid. These 

 moths are very tenacious of life, and like the Zygaenas it is difficult to kill them by a squeeze. However, 

 the resemblance of the two families is only superficial, being caused by similarity in the shape of the wings 

 and body, and not by any real relationship, as has already been mentioned on page 4 of the present 

 volume. On closer observation many external differences \\dll be noticed; for instance, when the Syn- 

 tomids are resting, the wings are as a rule more spread out, while in the Zygaenae they are laid close 

 along the body; an exception form only those genera of Syntomids which mimic Ichneumonids and there- 

 fore have the wings folded close over the body so as not to betray themselves, e. g. the South American 

 genus Trichura already mentioned above. 



The Syntomids are distributed all over the warm and temperate zones of the earth, but are 

 common only in the tropics and subtropics. In the temperate region of America the number of species, 

 which can be counted by the hundred in Central America, dwindles quickly down to 20, and there are 

 only 4 European species as compared with the very large number in tropical Asia. While numerous Syntomids, 

 often with a beautiful burnished gold colouring, inhabit tropical Africa, only one small form is known to 

 occur in Africa north of the Sahara. 



Most Syntomids, hke the Zygaenids, appear in large numbers of individuals. The largest German 

 form, Synt. jihegea, may be observed flying up and down on sunny slopes in great abundance. In CTiina 

 Umbellifers resembling hemlock and growing along the trenches are sometimes literally covered with 

 the yellow-ringed species of Syniomis, so that one can simply pick them off with the killing-bottle. In 

 Brazil I caught over 20 different species in one hour on a patch only a few yards square overgrown with 

 a kind of Spiraea, and in Ceylon I once found such a multitude of Syntomis passalis, which is easily 

 mistaken for a wasp when on the wing, that I thought I had happened on a wasp's nest. 



About 1200 forms of Syntomids are known, which Hampson classifies in about 150 genera in his 

 recent monograph, the genus Syntomis alone containing 150 forms. In the Palearctic region occur only 

 3 genera, apart from the 50 mostly Asiatic forms of the genus Syntomis. 



