14 american hymenoptera. 



References. 



Serres, Geognosie des terrains tertiaires, p. 299 1829. 



Sordelli, Bull. Soc. Ent. Ital., XIV, p. 228, fig 1882. 



Scudder, Bull. U. S. Geol. Surv., No. 31 (Fossil Insects), p. 98. ..1886. 



Morley, British Ichneumons, I, p. 39 1903. 



Handlirsch, Die Fossilen Insekten, pp. 849, 1129 1906-1908. 



Life History and Habits. 



Most of the different members of this tribe are often seen 

 flying slowly about shrubbery or in the tall grass during the 

 day from April or early May till late October, but in the 

 tropics and occasionally even in parts of the United States 

 they are taken at various times during the rest of the year. 

 In cloudy or wet weather they seek some sheltered place — 

 at least the diurnal species do — and very little is known of 

 the nocturnal forms, O. bifoveolatus, etc. The " longtailed " 

 and "purged" Ophions — Eremotylus niacrurus and Enicos- 

 pilus purgatus — Ophion bilineatus and Thyreodo7i ^norio are 

 most commonly taken and are most abundant in most collec- 

 tions. The females are more common in museum material 

 owing to their activity in searching for suitable hosts for 

 their eggs, a fact well brought out by the Cornell trap-lantern 

 records which show that only 87 males were taken to 485 

 females. 



The method of oviposition is probably the same for all the 

 members of this tribe, but the shape of the Qq,z and the 

 larval habits, though not well known, appear to vary some- 

 what, at least the records do not agree. Trouvelot describes 

 the oviposition of Eremotylus macrurus as follows : " When 

 an Ichneumon detects the presence of a worm she flies 

 around it for a few seconds, and then rests upon the leaf near 

 her victim ; moving her antennae very rapidly above the body 

 of the worm, but not touching it, and bending her abdomen 

 under the breast, she seizes her ovipositor with her front 

 legs and waits for a favorable moment, when she quickly 

 deposits a small, oval, white o.^^ upon the skin of the larva. 

 She remains quiet for some time and then deposits another egg 

 upon the larva, which only helplessly jerks its body every time 



