How insects behave 



are workers, and can both bite and sting. They sting to paralyse their 

 insect prey, and bite to feed themselves with fruit or other sugary 

 foods, to masticate food for their larvae, and to scrape off fragments 

 of wood to build cells in their comb. 



Later in the summer bigger cells are built, and in these fertile females 

 and fertile males are reared. The sterility of the workers is a result of 

 insufficient, or incomplete feeding of the larvae, and fertile females can 

 be produced by improving the diet. The males develop from unfertilised 

 eggs. As we have seen, the female parent receives sperm from the male 

 and stores it in a receptacle called a spermatheca, from which the eggs 

 are fertilised before they are laid. Towards autumn eggs begin to be 

 laid without having been fertilised. 



After the mating flight, the males and the workers all die, and only 

 the fertilised queens survive to start new nests in the following year. 



Bees 



Like the wasps, the bees are mainly solitary, but they also demonstrate 

 various intermediate steps towards the full social Hfe of the honey-bee. 



Bees are not carnivorous. They have mandibles, which are sometimes 

 well developed, as in the leaf-cutter bees, but the principal feature of 

 the mouthparts is a 'tongue' formed from the very much lengthened 

 glossae of the labium (Fig. 25e). Flowers conceal a store of nectar, a 

 sugary solution, which the bees collect and keep for a while in their crop, 

 where it undergoes chemical action, and is transformed into honey. The 

 honey is later brought up again and stored in the cells of the hive. 



Besides the nectar, a flower exposes pollen on its stamens in such a 

 position that the bee brushes against it when it takes the nectar. As the 

 bee goes from flower to flower it transfers pollen from one blossom to 

 another, and so ensures cross-pollination. At the same time the bee 

 generally collects the pollen that sticks to its hairy coat, and carries it in 

 special pollen-baskets, usually on the hind-legs, but sometimes under- 

 neath the abdomen. If you watch a bee visiting flowers you will see these 

 yellow masses of pollen, often absurdly big for the size of the insect. 



Like the solitary wasps, the solitary bees (Fig. 6i) live in holes in soil 

 or sand, or in burrows in decaying stumps and posts, and congregate 

 in suitable places to give a community or colony of individuals living 

 close together, but not taking part in a true social Hfe. They provision 

 their cells then lay an egg and close the cell, leaving the larva to fend for 

 itself when it hatches. The leaf-cutting bees (Megachile) cut out neat 

 pieces from the leaves of roses and other garden plants, and use them 

 to Une their cells inside burrows in rotting posts. The mason-bees {Osmia) 

 build cells of a salivary cement containing fragments of wood, sand 

 or soil, and put them in odd cavities and crevices, including key-holes. 



lOI 



