UNITED STATES DEPARTMENT OF AGRICULTURE 



MISCELLANEOUS PUBLICATION NO. 174 



WASHINGTON, D.C. 



DECEMBER, 1933 



THE SERPHOID AND CHALCIDOID PARASITES 

 OF THE HESSIAN FLY 



By A. B. Gahan, senior entomologist, Division of Identification and Classifica- 

 tion of Insects, Bureau of Entomology 1 



CONTENTS 



Page 



Introduction 2 



General history 2 



Host relationship 3 



Superfamily Serphoidea 4 



Family Platygasteridae 4 



Platygaster hie malis Forbes 4 



Platygaster zosine Walker 10 



Platygaster herrickii Packard 14 



Platygaster error Fitch 18 



Trichacis remulus (Walker) 22 



Superfamily Chalcidoidea 25 



Family CaUimomidae 25 



Ditropinotus aureoviridis Crawford 25 



Pseuderimerus mayetiolae Gahan 30 



Pseuderimerus femoratus, new species 32 



Pseuderimerus semiflavus, new species 33 



Family Eurytomidae 33 



Eurytoma phoebus Girault 33 



Eurytoma atripes, new species 36 



Decatoma amsterdamensis Girault 38 



Family Eupelmidae 41 



Eupelmus allynii French 41 



Eupelmus atropurpureus Dalman 46 



Eupelmus karschii Lindeman 51 



Eupelmella vesicularis (Retzius) 52 



Calosota metallica Gahan 58 



Family Encyrtidae 60 



Cheiloneurus elegans (Dalman) 60 



Family Pteromalidae 65 



Amblymerus mayetiolae (Gahan) 65 



Polyscelis modestus Gahan 67 



Meraporus crassicornis Kurdjumov 70 



Superfamily Chalcidoidea— Continued. _ 



Family Pteromalidae— Continued. Pa & e 



Arthrolytus maculipennis (Walker) 71 



Eupteromalus juMpes (Forbes) 75 



Eupteromalus americanus, new species 82 



Eupteromalus micropterus (Lindeman) ___ 86 



Merisus destructor (Say) 89 



Merisus febriculosus Girault 95 



Merisus mordellistenae Crawford 99 



Merisus cognatus, new species 102 



Merisoporus chalcidiphagus (Walsh and 



Riley) 104 



Callitula bicolor Spinola 109 



Bubekia fallax, new species 114 



Halticoptera aenea (Walker) 116 



Family Aphelinidae 121 



Tumidiscapus flavus Girault 121 



Centrodora speciosissima (Girault) 124 



Family Eulophidae 128 



Horismenus texanus (Girault) 128 



Pleurotropis benefica Gahan 131 



Pleurotropis metallicus (Nees) 133 



Tetrastichus carinatus Forbes 138 



Tetrastichus productus Riley 143 



Tetrastichus ainsliei Gahan 144 



Other species recorded in literature as para- 

 sitizing the hessian fly 145 



Coelopisthia forbesii (Dalla Torre) 145 



Hoplogryon kansasensis Gahan 146 



Lygocerus triticum (Taylor) 146 



Synaldis incisa Gahan 146 



Unpublished records that are considered 



doubtful 146 



1 The preliminary work was greatly facilitated by an incompleted manuscript written 

 by the late P. R. Myers shortly before his death in 1925. Myers had devoted many 

 years to the study of hessian-fly parasites and had brought together bibliographies and 

 descriptions of 29 different species, together with a number of illustrations. His manu- 

 script was not in form for publication, however, and although consulted freely in the 

 preparation of the present paper, the entire subject matter has been rewritten and 

 rearranged, even the bibliographic references being greatly augmented and brought up 

 to the end of the year 1982. The descriptions, synonymy, and review of literature, 

 as well as the remarks on hosts, life histories, distribution, etc., are all by the present 

 writer. The illustrations accumulated by Myers have been utilized, but in many in- 

 stances these have been revised, and a number of other drawings made under the 

 writer's supervision have been added. It is deeply to be regretted that Myers was 

 unable to complete his paper, and the writer is pleased to acknowledge the help that 

 it has been in connection with the preparation of this publication. To all the many 

 field workers of the Division of Cereal and Forage Insects of the Bureau of Entomology 

 and to others whose notes on biology, distribution, hosts, and life histories have been 

 freely consulted or who have furnished a large part of the thousands of specimens 

 studied, sincere thanks are accorded. The whole-hearted cooperation of C. C. Hill, 

 of the Carlisle (Pa.) laboratory, in this respect deserves special mention. The numerous 

 illustrations were drawn by E. H. Hart, formerly artist of the Division of Cereal and 

 Forage Insects ; Mrs. Eleanor A. Carlin, artist of the Division of Identification and 

 Classification of Insects ; and W. R. Walton, senior entomologist of the Division of Cereal 

 and Forage Insects. 



1 



