1900.] 117 



ON SPEEOOPHAaA VESPARUM, Cubt. 

 BY CLAUDE MOELEY, F.E.S. 



Our knowledge of the Ichneumonidce (sensu stricto), especially in 

 this country, ia so deplorably slight and incertain, that any reliable 

 information that may be forthcoming upon them will be welcomed, if 

 not by this, by a future generation with due thankfulness. There is 

 one species in particular whose most interesting oeconomy early at- 

 tracted my attention, and, by setting it forth in as succinct a manner 

 as may be, I hope to rekindle some embers still smouldering of the 

 transitory enthusiasm felt in the late J. B. Bridgman'a most excellent 

 work upon parasitic Hymenoptera of twenty years ago. 



The first mention I can find of Sphegophaga vesparum is in the 

 ever-modern Eev. William Kirby's learned Bridgwater Treatise of 

 1835. In it he states (II, 334) that soon after August, 1824, Eev. 

 F. W. Hope, upon opening some cells in a wasp's nest, was surprised 

 to find several specimens of an Ichneumon belonging to Jurine's 

 genus Anomalon. Hope himself, at a Meeting of the Ent. Soc. Lend, 

 held on June 4th, 1838, brought forward this occurrence as an illus- 

 tration of compound parasitism, believing, at that time, his Anomalon 

 to have been preying upon Shipiphorus, and not directly upon the 

 Vespce, a theory since abundantly shown to be invalid {vide Proc. Ent. 

 Soc. Lond., 1838, iii, p. 177). That both insects should occur in the 

 same nests is but natural, since their pabula are identical ; no instance, 

 however, is recorded of mutual animosity on either part. 



On January 1st, 1828, Curtis published his description of vesparum, 

 and followed Hope in referring it to Jurine's genus Anomalon (1814), 

 disregarding TrypJion of Fallen (1813) with which he possibly was un- 

 acquainted. We may at least congratulate ourselves that order is 

 approaching, if slowly, from chaos, when we find him giving as type 

 of the genus Ichneumon (Bassus) Icetatorius, Fab., with which we now 

 regard vesparum as agreeing only in so far as their mutual reference 

 to the subfamily Trtphonides, an agreement, however, not extending 

 to Anomalon, Jur., which falls into the Ophionides. Satzeburg has 

 described the same insect (Ichn. d. Forst., 1844-52) with some hesita- 

 tion as a new species, under the name Tryphon vesparum. Its position 

 in this genus was also untenable on account of its distinctly petiolate 

 abdomen and its stout, elongate posterior legs ; on the latter account 

 probably — or possibly because he considered the abdomen sessile rather 

 than subsessile (which is very curious, since it is distinctly petiolate) — 

 Westwood (Mod. Class. Ins., ii, Synops. 57, 1840) proposed a new 



