43° 



Handbook of Nature-Study 



helpless while being eaten by a fat little grub which they would gladly 

 devour, if they could move. 



a. h, r. </. 



A mud-dauber and her ^icsts, with celts cut open 



showing a, larva full grown; b, cocoon; 



c, youiig larva feeding on its 



spider-meat and d, an 



empty celt. 

 Drawn by Anna C. Stryke. 



The wasp larva is a whitish, plump grub and it eats industriously until 

 the spider meat is exhausted. It then weaves a cocoon of silk about itself 

 which just covers the walls of its home tube, Uke a silken tapestry; within 

 this cocoon the grub changes to a pupa. When it finally emerges, it is a 

 full-grown wasp with jaws which are able to cut a door in the end of its 

 tube, through which it comes out into the world, a free and accepted 

 mason. The females or queens, which issue late in the season, hide in 

 warm or protected places during the winter; they particularly like the 

 folds of lace window curtains for hibernating quarters. There they 

 remain until spring comes, when they go off to build their plaster houses. 



There are about seventy species of mud wasps in our country. Some 

 provision their nests with caterpillars instead of spiders. This is true of 

 the jug-builder, which makes her nest jug-shaped and places tv/o or three 

 of them side by side upon a twig. She uses hair in her mortar, w4iich 

 makes it stronger. This is necessary, since the jug is saddled upon twigs 

 and is more exposed to the rain than is the nest of the most common mud- 

 dauber. The jug-builder is brown in color and has yellow markings on 

 the abdomen; but she does not resemble the yellow- jackets, because she 

 has a threadlike waist. There are other species of mud wasps which use 

 any small cavity they can find for the nest, plastering up the opening after 

 the nest has been provisioned and the egg laid. We often find keyholes, 

 knot-holds and even the cavity in the telephone receiver, plastered up by 

 these small opportunists. 



The mud -dauber which is the most common, and most likely to be 

 selected for this lesson, is a slender creature and looks as if she were made 

 of black tinsel; her body gives off glints of steel and blue; her abdomen 

 constantly vibrates with the movement of breathing. Her eyes are large 

 and like black beads; her black anteimae curve gracefully outward, and 

 her wings, corrugated with veins, shimmer with a smoky blue, green and 

 purple. She stands on her black tip-toes when she walks, and she has a 



