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JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 8 



NOTES ON ICHNEUMON L^TUS BRULLE i 



By Harry H. Knight 



While breeding parasites from the army-worm {Leucania unipuncta 

 Haworth) during the summer of 1914, males of Ichneumon Icetus 

 Brulle were bred in considerable numbers from the pupae. The 

 parasites began to emerge August 15 and continued to appear during 

 the week following. By August 24 females of Ichneumon funestus 

 Cresson and Ichneumon canadensis Cresson began to emerge from the 

 pupge. On August 25 a male of I. Icetus was observed to copulate with 

 a newly emerged female of I. funestus. The female was resting on an 

 oat straw when the male approached from in front (PL 29, fig 2), 

 grasped her quickly by the legs, and at the same time thrusting his 

 abdomen below and clasping the ovipositor with the tip of the abdo- 

 men. Copulation was observed three different times and in each 

 case it lasted about one-half minute. 



In rearing specimens it was noted that the abdomen of certain fe- 

 males was entirely ferruginous at emergence and then after a few hours 

 acquired the black coloration at the base of the segments. I. cana- 

 densis and /. funestus are separated on the basis of the presence or 

 absence of black at the base of the abdominal segments. A series of 

 specimens shows a gradation of forms from the typical canadensis 

 to funestus. From these observations it appears that they are females 

 of the same species. The female of 7. Icetus and the males of I. 

 funestus and /. canadensis have heretofore remained unrecognized. 

 Brulle (1846) described I. Icetus from a male. In a note following the 

 description a female is mentioned and certain points of difference are 

 described. Evidently this female was some other species for both 

 Provancher and Cresson were unable to recognize the female of I. 

 Icetus. Say, in 1835 described the male Icetus but instead of giving it 

 a new name he referred to it as being the male of a previously described 

 species, Ichneumon paratus Say. 



It may be concluded from the foregoing breeding experiments that 

 I. canadensis Cresson and I. funestus Cresson are females of Ichneumon 

 Icetus Brulle. Since Ichneumon Icetus Brulle has priority over Cres- 

 son's species the latter must be considered synonyms. 



The males of I. Icetus have been taken during the winter months in 

 decaying logs. On a warm day last December the writer took a male 

 specimen on the walk in front of the Cornell Insectary. On March 

 14, 1915, some twenty specimens, all females, were found hibernating 



1 Contribution from the Department of Entomology of Cornell University. 



