372 THE STUDY OF INSECTS 



flat stones or to the ceilings or walls of buildings. These nests usually 

 consist of several tubes about one and one-fifth inches in length placed 

 side by side (Fig. 618) and are provisioned with spiders. The mud- 

 daubers may be seen in damp places collecting mud for their nests, or 

 exploring buildings in search of a place to build. They have a curious habit 

 of jerking their wings frequently in a nervous manner. There are in this 

 country two widely distributed and common species of 

 mud-daubers; these are the blue mud-dauber, Chalybion 

 cam Hum, which is steel blue with blue wings, and the yel- 

 Vig. 6iQ.—Scdiphron low mud-dauber, Sceliphron cementarium, which is black 

 cemeniarium. or brown with yellow sp< )ts and legs (Fig. 619). The lat- 



ter of these species has been commonly described under the generic name 

 Pelopczus. 



The tool-using wasps, Ammophila. ■ — Among the members of the 

 sphecoid wasps that burrow in the ground and store their nests with 

 caterpillars arc certain species of the genus Ammophila. These are of 

 especial interest on account of the habit first observed by the Peckhams, 

 of pounding down the earth with which they close their burrow by tak- 

 ing a stone or some other object in their mandibles and using it as a hammer. 

 The genus Chlorion, formerly known as Sphex, includes species which 

 are among the most common of flower visitors in the warmer parts of our 

 country, and are among the largest and most handsome, and therefore 

 most often observed of our wasps. In the West the common, very large, 

 all metallic green, Chlorion cydneum, is a very striking insect; and in the 

 East, Chlorion ichneumoneum, which is brownish-red with the end of the 

 abdomen black, is the most noticeable. 



Fig. 620. — Sphccius speciosus. 



The cicada-killer, Sphecius speciosus.- This is a large handsome wasp 

 about i£ inches in length (Fig. 620). It is black sometimes of a rusty 

 color, and has the abdomen banded with yellow. It is particularly 

 abundant in July from New Jersey southward. It digs its burrows 

 usually in the drier situations and stores at the bottom in enlarged cells 

 one or more cicadas. The wasp locates a cicada in a tree, suddenly 

 stings it, thus paralyzing it when both fall to the ground. The wasp 

 then laboriously drags the cicada to its burrow, perhaps flying part of the 

 way, the whole operation often taking an hour or more. When the 

 cicada is finally stowed away at the bottom of the burrow the wasp lays 

 an egg on its body where it hatches and the young wasp larva feeds on 

 the paralyzed victim. 



