CHARLES W. HOOKER. 139 



Allocamptus Thomson was a homonym, the genus was not 

 valid until a new name was proposed by Kriechbaumer in 

 1901. Others may determine the delicate question whether 

 Eremotylus Forster should date from 1868 or 1889, but I con- 

 sider it as certainly established in 1889, when a species was 

 first designated. I recognize the movement in favor of a 

 rule that no generic name shall have standing until a recog- 

 nizable species has been placed under it, although this is not 

 as yet adopted by the International Commission on Zoologi- 

 cal Nomenclature. Until the adoption of such a rule it would 

 seem that Eremotylus Forst. must hold. Such a rule would, 

 however, eliminate the generic names Eremotylus and Allo- 

 camptus of Forster, and Allocamptus Thomson would then 

 become the generic name for this group. 



Distribution. — The species of this genus are widely distri- 

 buted from the southern part of boreal North America to the 

 southern part of South America, including the West Indies. 

 E. macrurus has perhaps the widest range, having been taken 

 from Ottawa, Canada, to Central America and Trinidad. 

 The distribution of the other species is not as yet well known, 

 but is apparently more limited. 



Life history aud habits. — Little is known of the life histories 

 of the members of this genus, except for E. macrurus, but 

 they probably differ little from that of this species, which is 

 treated under the general heading for the tribe and the 

 species. 



Economic importance. — The host list of most of the members 

 of this genus is very incomplete, but so far as known they 

 are parasitic upon the Arctiidae and Saturniidae and one spe- 

 cies of Notodontidas. E. macrurus is a common parasite of 

 the large cecropia larvae and allied species, and the control 

 of these is undoubtedly due to the activity of these parasites. 

 The importance of E. inacrurus is, however, somewhat di- 

 minished by the fact that it often fails to make a proper 

 pupa ; the late Dr. J. B. Smith reported a case in which but 

 19 adults were obtained from 79 pupae. " In some localities, 

 at least, sound larvae and pupae are the exception, and one usu- 

 ally finds on cutting the cocoon only a putrid brown, semi- 



TRANS. AM. ENT. SOC, XXXVIII. 



