THERA VARIATA IN BRITAIN. 243 



variable, but always belonging to " typical variata,'" the larva 

 on Pinus picea. Recently the question has again been some- 

 what to the fore, e.g., Laplace (Mitt. Ent. Ver. Hamburg- 

 Altona, 1899-1904, p. 100) records variata "everywhere in spruce- 

 woods, probably two broods, middle of May to end of July, larva 

 May and June on spruce ; obeliscata everywhere in pine- 

 (Kiefern-) woods, irregular, but certainly double-brooded, end of 

 May to October, larva May and July-August on pine (Scotch 

 fir)." Blocker (Eev. Russ. Ent. viii. 48) writes in a similar 

 strain, that obeliscata is "unconditionally an independent species. 

 Besides the extraordinarily sharp distinction in design and 

 ornamentation, the two forms are distinguished in manner of 

 life : variata lives on spruce, but obeliscata on pine, and appears 

 a little later than variata. In pine-woods only obeliscata is 

 taken ; in spruce-woods only variata. Where both spruce and 

 pine grow together, both species occur together, but evidently 

 they do not mis, as intermediate forms are not met with." 



%i|' ^ 



9 Thera variata. ^ 



The above survey, which of course does not profess to be 

 exhaustive, will show that we have been much too " previous " in 

 merging the whole heterogeneity under the single name of 

 variata, and have now to submit to a third edition of the 

 inconvenience to which we were subjected nineteen years ago, 

 when the late C. G. Barrett announced the " true Acidalia 

 osseata" in Britain, and again, four years ago, when Messrs. 

 Sharp and Wightman introduced us to " Nonagria neurica in 

 Britain." When will entomologists learn the importance of 

 maintaining a separate name for a separate concept '? Whether 

 obeliscata be or be not a " species," it is an entity which we 

 ought never to have allowed ourselves to call ''variata'' ; if we 

 were very anxious to bolster up the Staudingerian theory, it 

 would, of course, have been permissible, though rather cumber- 

 some, to call our insect " variata obeliscata.'" 



For myself, I have always felt convinced that the two were 

 species, and I submitted the genitalia to Mr. Pierce several years 

 ago ; but as these unfortunately yielded nothing tangible, I 

 published nothing on the subject, unless possibly there be a 

 stray note in the Trans. City Lond. Ent. Soc, in connection 



