38 



The Ithomiinae. 



By W. J. Kaye, F.E.S. Eead December lltli, 1913. 



The ltho)iiiiu(i are a sub-family of the Danaida that exclusively 

 inhabit tropical and sub-tropical America. Although they have the 

 contour and flight like some Heliconines and Acrasines they are 

 sharply differentiated. Bates in his famous paper, ('ontrihiitinii>i to 

 an Insect Fauna of the Amazon Valley, published by the Linnean 

 Society in 1862, confused the relationship of this sub-family by 

 treating it as a sub-family of the HeliconidiT. He there called them 

 the Danaoid Heliconida:, while his Acrfeoid Helicnnida included the 

 genera Heliconins and Eueides. In a footnote, however, he refers 

 to Felder's then recent paper in the " Wiener Entomologische 

 Monatschrift " for March, 1862, where the two genera Heliconins 

 and Eueides are separated entirely from the Danaoid Helieonid(t and 

 placed by themselves in a separate family, the Helieonidce, thus leaving 

 the Danaoid Helicnnida to embrace what we now know as the Ithomiiiur. 

 They were still connected to the Heliconida, with which they have 

 no relation except in colouring. By reversing Bates' term Danaoid 

 Heliconida; and calling them Heliconoid Danaida, we get a most 

 appropriate term, for these butterflies at first glance do not have 

 any resemblance to true Danaids. Many authors have treated the 

 Danaoids, including the Ithomiines, as sub-families of the yi/mpJia- 

 lida, but while they are certainly related, they are doubtless far 

 enough removed to be treated alongwith tl e Danaines and Lycoreines 

 as a separate family. 



Some authors have raised the Ithotninia to family rank and termed 

 them Xeotro/a'da; but they have so many affinities with the true 

 Danaids that one is not warranted in so separating them. All 

 Danaids, including the three sub-families T>anaina\ Li/eoreina', 

 Itltomiinu , have the sub-median vein of the forewing bifurcated at 

 the base, while all Nymphalids have the sub-median vein, or vein 1, 

 simple, except in the aberrant genus Colanis, when both the median 

 and sub-median veins are bifurcated at the base. The Danaids are, 

 however, linked with the Nymphalids by the imagines having the 

 front pair of legs aborted and useless for walkmg. The aberration 

 is very great in the males, but less so in the females, as is found 

 also in the Enjrinida'. Having placed them with the Danaidn , one 

 may diagnose the Ithomiina as follows : — 



Wings usually long and narrow, antenniB long and thin, with a 



