FHEY LOOK LIKE 



II 



HORNETS' AND YELLOW JACKETS' 

 NESTS are made of a papier-mache' 

 material; the wasps produce it by 

 chewing up rotted wood, dead stems 

 and leaves, or paper and cardboard 

 fragments. The nests are large and 

 globular. They are usually found 

 aboveground — on branches of trees, in 

 shrubbery, on gables. Some hornets 

 and yellow jackets build nests under- 

 ground. 



A POLISTES NEST is also made of a 

 paperlike material that the wasps pro- 

 duce. It is composed of a circular 

 comb of cells. The cells open down- 

 ward. 



MUD DAUBERS' NESTS ore made of 

 clay. They are often built around 

 dwellings or outbuildings, both inside 

 and outside. They are sometimes built 

 in stored machinery and equipment. 



Larvae depend on adults for their food and care. 

 The queen cares for the larvae of her first brood 

 (all of which are workers), feeding them daily 

 with freshly killed insects. Workers care for 

 larvae of subsequent broods. 



The larval stage lasts 12 to 18 days. As larvae 

 grow, they fill out the cells and depend less on the 

 gluey secretion to hold them in place. When full 

 grown, they spin silken cocoon caps over the cells 

 and transform to pupae. 



Pupae are motionless within their cocoons. 

 They resemble adults except for a thin, trans- 

 parent membrane that covers them. At first they 

 are creamy white, but gradually color comes to 

 wings, legs, antennae, and other body parts. At 

 the end of the pupal stage, which lasts about 12 

 days, the covering membrane breaks, and an 

 adult emerges. 



Once her first brood matures, the queen resumes 

 egg laying. A hornet or yellow jacket queen may 

 lay as many as 25,000 eggs; a Polistes, several 

 hundred. 



Most wasps are workers. During the life of a 

 colony, a hornets' nest or yellow jackets' nest may 

 contain as many as 15,000 workers to several 

 hundred queens and males. The ratio in a Polistes' 

 nest may be several hundred workers to a couple 

 of dozen queens and males. 



As soon as they appear, workers take complete 

 charge of nest life. They enlarge the nest by 

 building additional cells. They care for all imma- 

 ture larvae. They forage for food. 



• Mud Daubers 



Mud daubers also pass through egg, larval, 

 pupal, and adult stages in their development. 

 Only two adult forms exist — the females and 

 males. 



In the spring, young adults come out of nests 

 (where they have overwintered as pupae) and 

 mate. The females look for suitable sites to 

 build new nests in which to deposit their eggs. 

 Each selects a sheltered area, which may be in or 

 near a building, and begins constructing clay cells. 



First, the female builds a cell. Next, she catches 

 about 20 immature spiders, paralyzes them with 

 her sting, and stores them in the cell. Then, she 

 lays an egg in the cell and caps the cell with a 

 clay covering. She repeats this pattern until she 

 has built 6 to 20 cells. 



When her nest building, provisioning, and egg- 

 laying jobs are done, she leaves the nest and does 

 not return. The larvae hatch from the eggs and 

 begin feeding on the paralyzed spiders. In a few 

 days they spin cocoons and transform to pupae. 

 The pupae transform to adults in about 2 weeks. 



There may be 1 to 3 generations of mud daubers 

 each year, depending on the section of the country. 

 Females and males are about equal in number. 

 Upon reaching maturity, they leave their nests 

 and carry on their activities independently. 



NESTS 



Wasps can be identified by the nests they build. 

 The globular, papier-mache nests concealing multi- 

 combed structures are peculiar to hornets and 

 yellow jackets; the single-layer, open-faced, 

 umbrella-shaped nests, to Polistes; and the clay- 

 cell nests, to mud daubers. The size of the nests 

 varies with the number of wasps living in them. 



Hornets and yellow jackets continually enlarge 

 their nests to accommodate the growing popula- 

 tion. They do this by adding new combs or layers 



