CHAPTER XXIV 

 USEFUL INSECTS 



243. Useful Insects. Some insects are useful because 

 they supply food ; as the honey-bee. Others supply 

 materials for clothing, as the silkworm. Still others, as 

 we have seen, cause flowers to set fruit by carrying 

 pollen from flower to flower. (See K 167.) There are 

 many species which are especially useful in man's battle 

 with the forces of nature, because they prey upon the 

 injurious insects. 



244. Wasps. There are many kinds of wasps. The 

 common "red wasps" and "yellow jackets," with their 

 paper nests made out of the fragments of plants, are 

 well known. The mud-dauber is another common wasp. 

 There are many species of wasps that do not live in 

 colonies like the ones just mentioned, but live singly. 

 and are, hence, called "solitary wasps." The wasps are 

 somewhat related to the domestic bees, and bumble- 

 bees. But instead of storing nectar and pollen for food, 

 as the bees do, they fill the cells of their nest with the 

 younger stages of other insects as food for the young 

 wasps. The adults prefer nectar and pollen for them- 

 selves, however. The mud-dauber fills the mud-cells with 

 the bodies of young spiders, flies, etc., and before sealing 

 up the hole, deposits an egg. The food for the larva is 

 there ready for it when it is hatched. Wasps are said to 

 catch the biting flies that worry stock*, and, especially, 

 the larvae of the boll-worm. Wasps' nests should not be 

 destroyed except, possibly, in orchards. 



(176; 



