ICHNEUMON-FLIES, PART 2 [ EPHIALTINAE 429 



Most specimens were collected from mid-spring to early fall. Un- 

 usually early and late dates of capture are: April 17 in Norman Co., 

 Minn.; April 27 in Van Cortland Park, New York City; May 2 in 

 Black Mts., N. C. and at Plummers Island, Md.; May 10 at Clinton, 

 Ark. and at Linglestown, Pa.; September 9 at Madison, Wis.; Sep- 

 tember 15 at Plummers Island, Md.; September 20 on Mount Blaine, 

 near Canonsburg, Pa.; September 30 at Columbus, Ohio; and October 

 11 at Chattanooga, Tenn. 



Some of the above specimens were reared from wood or found 

 ovipositing in wood. There are 2 rearings from Carya, 1 from Fagus, 

 and 1 record of a female ovipositing in Carya. The subspecies has, 

 however, been observed ovipositing scores of times and there are 

 some published records (see references above) of miscellaneous ob- 

 servations. It is considered to be always parasitic on Tremex columba 

 boring in dead or dying hardwoods. 



This subspecies is in the Alleghanian, Carolinian, and Austroriparian 

 faunas. It is found flying through hardwood forests, or on or about 

 logs, trees, or stumps infested with Tremex columba. Adults occur 

 from mid-spring to early fall. 



4. Megarhyssa macrurus (Linnaeus) 



Male: Front wing 7 to 21 mm. long; cheek about 0.7 as long as 

 apical width of mandible; median part of apical edge of first sternite 

 at or a little beyond spiracle of first tergite; median membranous 

 streak of tergites 3-5 extending about 0.5 the length of the tergite; 

 apicolateral angles of tergites 3-5 about 60°. 



Female: Front wing 18 to 29 mm. long; cheek about 0.9 as long as 

 apical width of mandible; median part of apical edge of first sternite 

 about opposite middle of spiracle of first tergite; apicolateral angles 

 of fourth and fifth tergites about 85°; fourth tergite covered with 

 fine, rather dense punctures except near apex; ovipositor sheath 

 about 3.0 as long as front wing. 



There are three subspecies, as keyed and described below: 



MALES 



1. First and second tergites without a subapical yellow band, or rarely with a 



trace of a band; wings suffused with yellowish brown and with darker 

 yellowish brown spots; range: west of Rocky Mts. 



4c. macrurus icterosticta Michener 



First and second tergites with a subapical yellow band; wings hyaline or 



suffused with brown, also with brown spots 2 



2. Wings hyaline, the front wing with brown spots (fig. 319, d); range: Canadian, 



Transition, and Upper Austral zones east of Rocky Mts. 



4a. macrurus lunator (Fabricius) 



Wings suffused with brown, the front wing with brown spots; range: Lower 



Austral zone east of Rocky Mts, . . . 4b. macrurus macrurus (Linnaeus) 



