Natural History 038 



plants or on the bark and wood of trees, hut many others are 

 carnivorous and destroy numbers of wireworms, "leather- jackets" 

 (the larva? of the "Daddy-long-legs"), Saw-Fly larvae, and other 

 insects which are detrimental to crops. Others, again, feed on 

 the decaying flesh of dead animals, and the busy "Burying 

 Beetles," which join forces in their work, act as useful bands 

 of scavengers. 



An Important Linkage 



Other groups of Insects, with quite different mouth ap- 

 pendages, belong to the sucking types, which feed on liquid food. 

 Instead of cutting, toothed jaws, they have sucking-tubes, often 

 accompanied by sharp piercing needles as in the Mosquito, which 

 pierce the skin and suck in the blood of the victim. The nectar 

 of flowers is another great source of liquid food, and is sought by 

 Bees, Butterflies, Moths, and others which have sucking mouth- 

 organs. Perhaps the most important linkage in the whole system 

 of animate nature is the linkage between flowers and their 

 welcome insect visitors. For these visitors secure cross fertilisa- 

 tion, and this is often essential to seed-bearing. 



7 

 Life-histories 



There are various ways in which the young forms of Insects 

 hatch out from the shells within which they develop. Some 

 caterpillars eat through the shell; some maggots wriggle until 

 it breaks; and some larva? have special instruments for the 

 purpose. Thus the larval flea has a temporary piercing organ on 

 its head. Many larva? differ markedly from the adult forms, and 

 they are of several different types; they may be active, long- 

 legged, flat-bodied (campodeiform) larvae (very like the primi- 

 tive Bristle-tails), e.g. many beetle larva?, May-Flies, Stone- 

 Flies, etc. ; or they may belong to the more wormlike (cruciform) 

 group, such as caterpillars (i.e. young of moths and butterflies), 



