74 MISC. PUBLICATION 174, U.S. DEPT. OF AGRICULTURE 



label " Type." This specimen also bears labels showing that it was 

 reared from the hessian fly in France, and since it agrees with Ash- 

 mead's description of the male, there can be no doubt that it is the 

 type male of Ashmead's species. This specimen has been compared 

 with a male specimen determined by Foerster as Pteromalus maculi- 

 pennis Walker and found to be apparently the same species. The 

 female type of Holcaeus cecidomyiae is not identified in the collec- 

 tion by label. Associated with the type male in the collection is 

 another pin without labels except for a small tab upon which is the 

 figure 3, and bearing a card point upon which are mounted a male 

 specimen of the same species as the male type and beside it a female 

 which is easily recognized as Merisus destructor. A third pin associ- 

 ated with the male type bears a male of M. destructor and a female 

 which the writer has identified as Arthrolytus maculipennis. This 

 pin also bears a label " France " and a small tab with the figure 3 

 exactly like that on the pin previously mentioned. There can be no 

 doubt that all these specimens were received by Ashmead from 

 Marchal. Comparison of Ashmead's description with the female of 

 M . destructor shows it to fit that specimen completely, except in the 

 matter of the antenna. His description of the antenna cannot apply 

 to M. destructor, but it does fit very completely the antenna of the 

 female identified by the writer as A. maculipennis. It appears cer- 

 tain, therefore, that the two females associated with the male type 

 were the basis of Ashmead's description and that he drew the main 

 part of his description from the female of M. destructor but took 

 the description of the antenna from the A. maculipennis female. In 

 view of the fact that neither of these specimens fits the description 

 completely, neither can rightfully be considered the holotype of the 

 species. The male, however, does agree with the description and it 

 is therefore chosen as the holotype. 



The National Museum possesses a male and a female specimen 

 identified by Foerster as Ptevomalus maculipennis Walker; also a 

 male and a female identified by Ruschka as that species. These 

 specimens were obtained through an exchange with the Naturhis- 

 torisches Museum in Vienna, and were taken by the writer to the 

 British Museum, where they were compared with Walker's types 

 of P. maculipennis and found to agree completely. The above- 

 discussed male type of Holcaeus cecidomyiae and the female iden- 

 tified as A. maculipennis associated with it have been compared with 

 these specimens and found to agree in all essential details. 



Arthrolytus punctatus Thomson and Pteromalus maculipennis 

 Walker are certainly the same species. The specimens identified 

 by Foerster as maculipennis and found by the writer to agree with 

 Walker's type also agree with Thomson's description of punctatus 

 and with a specimen in the National Museum collection identified 

 by Schmiedeknecht as Thomson's species. This species is the geno- 

 type of Arthrolytus. It does not agree with the description of 

 Holcaeus, being excluded by the fact that the dorsum of the pro- 

 thorax is not acute anteriorly, the head is not triangular, and the 

 conformation of the abdomen is different. 



In the same paper in which he described Holcaeus cecidomyiae, 

 Ashmead listed Homopoi^us luniger (Nees) as a parasite of Maye- 

 tiola avenae Marchal. This record was also published by Marchal, 



