NEST OF ODYNERUS — CLARK AND SANDHOUSE 91 



female, March 23, at 9 : 15 a. m. and another on the same date at 

 10 a. m. 



Total, 4 males and 6 females. 



The male that emerged shortly after 9 a. m. was assisted by the 

 wetting of the nest. Not long after emergence he retreated within 

 the cell and remained looking out. The female that emerged after 

 the wetting of the nest retired into a cell about 1 p. m. and spent the 

 rest of the day there. 



The emergence holes of the males are 4 mm in diameter and those 

 of the females are 6 mm in diameter. 



Parasite.— One of the cells that was opened before the emergences 

 began contained a dead larva and a dead adult tachinid, with its pupal 

 skin. The tachinid was very moldy. It was determined by David G. 

 Hall as one of the Miltogrammini. 



Contents of other cells.— Dq^lA larvae, 4; dead male, 1; dead female, 

 1; crippled female, 1; male ready for emergence (March 3), 1; living 

 larva (February), 1; empty, except for mold, 1. 



Eahits. — Immediately after emerging most of the wasps were nerv- 

 ous and suspicious, and if a hand was brought within 4 or 5 inches 

 of them they faced it and took a defensive attitude. But none of 

 them were in the least aggressive, and the female that emerged on 

 March 23 paid no attention to a finger within half an inch. The 

 suspicious attitude on the part of the others was soon lost, and they 

 showed no concern when objects in their jar were rearranged with 

 the hand or when a finger came within an inch or less of them. How- 

 ever, they were not disturbed on sunny days when they were flying 

 about. 



In sunlight they are very active, but if it becomes cloudy they 

 cease flying at once, crawl about for a while, and come to rest, no 

 matter how warm it may be. 



The flight of the females is direct and clumsy. The flight of the 

 males is more agile than of the females, with frequent quick turns 

 and much hovering, accompanied by an oscillation from side to side 

 covering a distance of about an inch and a half. The females occa- 

 sionally hovered, remaining stationary in the air with the body ai 

 an angle of about 45°. 



When resting the wings are held parallel close down upon the back, 

 and usually the fore legs are drawn up from the supporting surface, 

 sometimes with the tips of the tarsi crossed. The antennae diverge 

 at an angle of 90° and are slightly ascending. In the females the 

 antennae are straight, but in the males the distal fourth is recurved 

 so that the tip points backward at an angle of about 45° with the 

 body axis. When completely at rest the head is tilted forward and 

 the antennae are depressed so that they almost or quite touch the 

 supporting surface. 



