More than 2,5Q0 species of wasps occur in 

 North America. Only about 50 are troublesome 

 to man. They are divided into the following 

 groups : 



Hornets and yellow jackets (Vespa, Vespula). 



Polistes (no common name). 



Mud daubers (Sceliphron, Chalybion, and 

 Trypoxylon) . 



These wasps build nests in or around homes — 

 beneath eaves, on porches, behind blinds, in trees, 

 in shrubbery, in rock fences, and in the ground. 

 If someone disturbs a nest, he may get stung 

 severely. 



A wasp stings by driving its needlelike ovi- 

 positor into the flesh and injecting a venomous 

 fluid into the wound. This causes a painful swell- 

 ing that may last several days. In some cases it 

 may be necessary to see a doctor. 



Most wasps kill destructive insects and are 

 therefore beneficial. Polistes catch corn ear- 

 worms, armyworms, and other pests, and feed 

 them to their young (larvae). Hornets and yel- 

 low jackets feed their young on house flies, blow 

 flies, and caterpillars of a variety of moths. But 

 when wasps build nests too close to the house or 

 in shrubbery where children play, they should be 

 destroyed. 



HOW THEY DEVELOP 



• Hornets 



• Yellow Jackets 



• Polistes 



Hornets, yellow jackets, and Polistes develop in 

 the same way. Three adult forms exist: 



1. Fertile females (queens) , which lay the eggs. 



2. Fertile males, which mate with the queens. 



3. Workers, which are females and usually 

 sterile. (Workers may occasionally lay eggs 

 without mating when the queen dies before the 

 end of the season.) 



In the fall, queens and males leave the nest and 

 mate. The males die shortly thereafter, but the 

 queens hibernate in a crack in a rock, under loos- 

 ened bark of a tree, in buildings, or in a hole in the 



WHAT! 



HORNETS AND YELLOW JACKETS are 

 built more stockily than Polistes and mud 

 daubers. They are black, and have yellow 

 or white markings. The queens measure 

 about % inch long; the males and workers 

 are about 72 inch long. These wasps are 

 most abundant in the northern temperate 

 region, but they also occur in arctic and 

 tropical regions. They are feared because 

 of their vicious sting. 



POLISTES are slender, elongated wasps; 

 they are % inch to I inch long. They are 

 black, brown, or red, and have a few 

 yellow markings. 



MUD DAUBERS are also slender and % 

 inch to I inch long. They are black and 

 yellow (as in the species Sceliphron), 

 metallic blue (Chalybion), or shiny black 

 (Trypoxylon). 



ground. Polistes queens also hibernate in attics 

 and basements. 



The following spring the queen comes out of 

 hibernation and begins flying about until she 

 comes upon a suitable nest site. She then collects 

 wood or vegetable fiber from nearby plants, chews 

 it into a paperlike substance, constructs a comb 

 consisting of a few shallow cells (later enlarged 

 into a nest), and lays an egg in each cell. She 

 does not lay any more eggs until her first brood 

 develops. 



The eggs are long, white, and slightly curved. 

 They hatch into larvae in 2 or 3 days. 



The newly hatched larvae are helpless, grayish- 

 white grubs that resemble the eggs. They hang 

 suspended in the cells, head downward. The 

 bodies stick to the cells by means of a gluey sub- 

 stance that they secrete. 



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