430 



WEST VIRGINIA EXPERIMENT STATION 



31, W. Va. Expt. Sta., 1893.) A very common parasite of the 

 larva and pupa of Polygraphus rufipennis throughout the 

 spruce forests. 



Mr. Ashmead refers to the two last mentioned species in a 

 letter dated Jan. 13, 1894, as follows: 



"The recognition of the two European species of Roptrocerus- 

 R. ecceptogastri and R. xylophagorum Ratzb.-is of special 

 interest. They were originally described by Ratzeburg in Vol. 

 I. Die Ichneu'd Forstinsectin (1844) p, 218. under the generic 

 name Pachyceras. 



"The following are the hosts of these insects after Ratzeburg, 

 but unfortunately I do not possess a late catalogue of the Euro- 

 pean Coleoptera and so can not give the names of the hosts as 

 changed by a later nomenclature." 



Parasite 

 Roptrocerus 



xylophagorum 



Host. 



Bostrichus bicolor 

 " bidens 

 11 curvidens 

 11 laricis 

 " piceae 



Pityographus 



" typoyraphus 

 l " villosus 



Roptrocerus 



ecceptogastri 



Later nomenclature. 



[ Taphrorychus tricolor. ] 

 \_Pityogencs bidens.~\ 

 [ " curvidens] 



[Tomicus laricis] 



[ Cryphalus piceae'] 



\_Pityopkthorus p ityogra- 

 phus.] 



[Tomicus typographies] 



[ Dryocoetes villosus] 



[Polygraphus polygraphus] 



' polygraphus 



41. Tetrastichus thanasimi A.shm.(=Tetrastichus sp. a. Bull. 

 31, W.^Va. Agr. Exp. Station.) Bred from larva of Thanasimux 

 dubius in bark of black spruce taken near Davis, Mar. 29, '91, 

 probably a secondary parasite. 



42. Tomicolia tibialis, n.g.,n. sp. Ashm,MS. Parasite of adult 

 Tomicus. Reared from adults of Tomicus calligraphus, taken 

 near Berkeley Springs, Mar. 10, '97; also from adults of 

 Tomicus pini, taken in bark of larch at Grand Forks, North 

 Dakota, July 17, '97, and from Tomicus cacographns taken in 

 pine bark near Dellslow, 1895 ; evidently a common parasite of 



