18 AMERICAN HYMENOPTERA. 



lieves that ichneumon flies of the subfamily Ophioninse may 

 produce infection since the insects are attracted to decaying 

 animal and vegetable matter, and might carry bacteria which 

 cause blood poisoning." Walsh states that he " has repeat- 

 edly had his fingers pierced by the ovipositor of Thyreodon 

 morio and always the puncture gave no more pain and pro- 

 duced no more inflammation than the puncture of a common 

 pin." The members of this tribe will undoubtedly try to 

 use the ovipositor if caught in the hand, and though the 

 smaller species may not perhaps pierce the skin a painful 

 wound could be made by one of the large forms. No poison 

 is, however, injected into the wound, so that the sole danger 

 is from bacterial infection, but in the tropics or under certain 

 conditions elsewhere this deserves consideration. The litera- 

 ture relating to this subject is as follows : 



Ophion morio, Walsh, Amer. Ent., I, p. 7 1868. 



Ophioninse Ashmead, Idem, p. 47... 1896. 



Paniscus Bitterman, Proc. Ent. Soc. Wash., IV, pp. 45-46 1898. 



Ophionidffi Nuttall, Johns Hopkins Reports, VIII, Ins. and Dis- 

 eases, Nos. 1-2, p. 41 1897. 



Ophion Morley, British Ichneumons, I, p. 29 1903. 



Natural Enemies. 

 At present only two members of this tribe are known to 

 have effective enemies. Over 170 adults of a small chalcidid, 

 Encyrtus Ikyreodoniis Ashm., were reared by Mrs. A. K. Dim- 

 mock* from a cocoon of Thyreodon morio. Fiske and Thomp- 

 sont report, from investigations at the Gypsy Moth Labora- 

 tory, that E. macrurus is frequently the victim of secondary 

 parasitism, for the host furnishes food enough for only one 

 parasite, and other parasites, threatened by starvation, attack 

 the larvse of E. macrurus if present. As instances of this 

 they have reared Theronia fulvescens Cress. ; Spilocryptus ex- 

 trematisX Cress. ; Hemiteles periliti Ashm.. ; a species of Pimpla 



^^immock, Proc. Ent. Soc. Wash., IV, pp. 149, 153, 1898. 



t Fiske and Thompson, Journ. Econ. Ent., II, p. 4601, 909. 



X In the paper it is written Spilocryptus extremis, but there is no 

 such species. Mr. Fiske states— in litt. — that "it is a lapsus for P. 

 exirematis Cress. The specimens show the species to be apparently 

 the form described by Cresson and usually placed as a synonym of 

 nuncius Say." 



