The Lasiocampids. 



By J. W. Tutt, F.E.S. Read February 24//1, 1898. 



The choice of the Lasiocampid moths, as the basis of a short 

 paper, was determined by the fact that I have recently been attempting 

 to get some general information with regard to this group. I cannot 

 say that I have succeeded very well, and I offer the few facts and 

 suggestions following rather as a basis for discussion than because 

 they have any inherent value per se. 



The Lasiocampid moths form a very restricted group in Britain, 

 containing only the following species: — Trichiura cratccgi, Pa'ci/o- 

 campa populi, Eriogaster lanestris, Lasiocampa quercus and Z. 

 trifolii, Macrothylacia rubi, Clisiocampa {Mai aco soma) neustria and 

 C. casirensis, Cosmotriche potatoria, Epicnaptera ilicifolia, and 

 Eutricha (Gastropacha) quercifolia. 



In Staudinger's "Catalog der Lep.," 1871, we find that there are, 

 besides the above, twenty-seven other Palaearctic species. These are 

 (using Staudinger's antiquated generic groupings) Chondrostega 

 pastrana ; Bombyx ilicis, franconica, alpiiola, neogena, /of/, vandalicia, 

 catax, rimicola, eversmanni,fasc/aiella ; Crateronyx taraxaci, ba/canica, 

 dumi, philopalus ; Lasiocampa albomaculata, prutii, populi/o/ia, tremu- 

 lifolia, suberifolia, lunigera, pini, bufo, tineosa, otus, femorata ; 

 Megasoma repanda. 



It will be remembered that I made some remarks on the nature of 

 genera in a paper * read before your Society in April last. In this 

 paper I discussed the theory of natural genera and what I then 

 termed "genera of convenience,"' and illustrated my remarks by the 

 British VanessH butterflies, a group almost every species of which 

 occurring in Britain belongs to a separate, well-defined genus when 

 the Vanessids of the world are taken into consideration. I then 

 pointed out that each genus should represent an evolutionary group, 

 and not just so many heterogeneous or homogeneous units as the 

 mind could readily remember. 



This is called to my mind because, in working out this family, 

 I observe that most of our Lasiocampid moths are lumped into one 

 genus, Bombyx, a name belonging by right to Bombyx mori, the 

 common silkworm moth of Asia aid Southern Europe, and therefore 

 representative of the Bombycid moths, a group in some respects 

 intermediate between the Sphingids and Lasiocampids. Thus one 

 reads of Bombyx casirensis, Bombyx rubi, Bombyx quercus, Bombyx 

 quercifo'ia, and so on ; and Staudinger gives the following hetero- 



* ' Some Considerations of Natural Genera and Incidental References to the 

 Nature of Species,' " Proc. South Lond. Soc," 1897, p. 20. 



