THE ENTOMOLOGIST. 



Vol. LIL] JUNE, 1919. [No. 673 



THE ANTIQUITY OF THE ICHNEUMONID^. 



By T. D. a. Cockeeell. 



Our principal source of information on fossil Ichneumonidae 

 is the important work of Prof. C. T. Brues, "The Parasitic 

 Hymenoptera of the Tertiary of Florissant, Colorado," in 

 ' Bulletin of Museum of Comparative Zoology,' January, 1910. 

 Brues remarks that the only parasitic Hymenoptera yet dis- 

 covered in pre-tertiary formations is the EpJdaltites of Meunier, 

 which was described from the Upper Jurassic of Spain. For 

 this fossil Handlirsch proposes a family, "Ephialtitidae," but its 

 characters are very obscure. Viereck remarks that it looks like 

 an Aulacine (Evaniidse), but there is really little resemblance. 

 Handlirsch notes that Meunier's reconstruction does not agree 

 well with the photograph. The venation cannot be determined 

 at all. Consequently I am rather at a loss to understand why 

 Brues should refer to the "quite typical character o( Ej^hialtites," 

 or regard it in any way as satisfactory evidence. It must, I think, 

 be altogether discarded as evidence of the mesozoic origin of the 

 Ichneumonidfe. Brues goes on to note the abundance of Ich- 

 neumonidpe and other parasitic Hymenoptera in the Tertiary 

 rocks as far back as the Lower Oligocene. He did not know that 

 certain fossils of the Piocky Mountain region are still older 

 than this, coming from well down in the Eocene. These, which 

 must be at least two million years old, and probably more, are 

 the oldest known Ichneumonidse. Scudder described five of 

 these Eocene ichneumons, supposing them to be of Oligocene 

 age. One {Ichneumon petrinns) is from Chagrin Valley, White 

 Eiver, Colorado ; the other four, assigned to Lithotorus (new 

 genus), RJiijssa, Glypta and Eclytns, are from Green Eiver, 

 V7yoming. The Idineuuion j^etrinus is evidently an ichneumonid, 

 but on account of its imperfect condition its generic position is 

 quite obscure. The Lithotorus is referred by Brues without 

 question to the modern genus Mesochorus. Concerning the 

 other three it can at least be said that they are veritable 

 ichneumons, with no visible characters separating them generi- 

 cally from living forms. I have now to add another Eocene 



ENTOM. — JUNE, 1919. M 



