70 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



NOTES ON THE NESTING HABITS OF SOME SOLITARY WASPS. 1 



BY J. B. PARKER. 



I. PSAMOPHILA VIOLACEIPENNIS (LEP.) 2 



In constructing their nests the wasps of this species dig down 

 more or less vertically to the depth of about an inch and then at 

 the bottom of the shaft construct a brood chamber usually at 

 one side. This is somewhat circular in shape varying from three- 

 fourths to one inch in diameter and is about half an inch in depth. 

 In digging the nest the wasp loosens a quantity of sand with her 

 mandibles and front feet, then gathers it up with her front legs 

 and holds it firmly pressed back into her grasp by the use of 

 her mandibles. With the load of sand thus firmly held she 

 backs out of the excavation to a short distance from the entrance, 

 drops her burden, steps forward over it and reenters the burrow 

 for another load. She is thus continually popping in and out of 

 her nest while it is in process of construction. While digging 

 the sand loose within the burrow the wasp makes a low humming 

 sound much like that which the mud-daubers make when con- 

 structing their nests, but by no means so loud. It requires about 

 ten minutes for the wasp to dig her nest, which is not begun until 

 after a caterpillar has been found and paralyzed. 



When the nest is complete the wasp hurries away to bring her 

 caterpillar, running over the sand instead of flying. She turns 

 the caterpillar upon its back, seizes it by the thorax with her 

 mandibles and walking astride it drags it to the nest. Whether 

 she uses the second pair of legs to support the larva while trans- 

 porting it I could not positively determine, but I am inclined to 

 think she does. She leaves the caterpillar at the entrance to 

 the nest, goes within, turns round, comes to the entrance and 

 having seized the caterpillar with her mandibles she backs into 

 the nest dragging her prey after her. The egg is placed trans- 

 versely on the side of the caterpillar on one of the more anterior 

 abdominal segments. After oviposition the wasp emerges from 

 the nest and seals up the entrance, in doing which she digs a 

 quantity of sand down into the opening and then rams it down 

 with her head, repeating the performance until the opening is 

 completely filled up. She then smooths over the surface above 

 the entrance to the nest and flies away. 



1 Contribution from the Biological Laboratory of the Catholic Univer- 

 sity of America, No. 2. 



2 Specimens of this species and also of the two following were kindly 

 identified by Mr. S. A. Rohwer. 



