ANTS, BEES, WASPS AND ICHNEUMON FLIES
These are of the order Hymenoptera (Membrane-wing). There are over 6,100 species in this order, some of them having great economic importance.
There are 36 species of ant in the British Isles, several of which occur in gardens. British ants are all vegetarians, taking nectar, seed juice, fruit and, in particular, the sweet exudation from greenfly known as honeydew. Ants are colonial, and big nests, especially those in secure positions such as under concrete footpaths, may last almost indefinitely. There are records of ant colonies 80 years old. They cause little trouble except when they swarm, usually during sultry weather in late summer, or when they enter the house.
Bees, of which there are 2-10 species of varying sizes in Britain, are divided into the social, which includes the hive bee and the bumble bee, and the solitary, which are the majority. They all depend on flowering plants for nectar and pollen. Social bees care for their young and these, in turn, care for the next generation in the colony.
Female solitary bees leave a supply of food in each cell, lay an egg on top and seal it up.
Most species of bumble bee (there are 25 species in Britain all about ½ to ¾ in. long) live below ground, colonies usually being very small and rarely exceeding 300 to 400. The queen alone survives the winter to found a new colony. The bumble bee is generally amber and black. Some species known as cuckoo bees are semi-parasitic, laying their eggs in the nest of other bumble bees and thus avoiding the task of raising their young.
There are about 28 species of leaf-cutter bee in Britain. The colours vary with the species, though many are amber and black. The size also varies, some are ¼ in. long, others smaller. They cut oval-shaped pieces out of tender green leaves, often rose leaves, and roll them between their legs to carry them away to use in nest construction.
In Britain there are approximately 100 species of mining bee, most of them being under ½ in. long—and of variable colour. They are solitary bees, looking not unlike hive bees, and lay their eggs singly in deep holes, often excavated in lawns. The spoil from the burrow is carefully spread round to avoid attracting attention to the opening. They help to pollenize and do no harm.
More than 280 species of wasp can be found in Britain. The common wasp is yellow and black, and ½ in. long. Like bees, they feed upon nectar, fruit juices and other vegetable matter, but feed their larvae on insects, spiders and other animal matter, thus acting as scavengers. Only the queen survives the winter to found a new colony.
Gall wasps are tiny little creatures, all under 1/2 in. long. They are rarely seen, but their presence is recognized by the galls produced by their larvae, such as oak apples and robin’s pin-cushions.
Ichneumon flies vary considerably in form—there are 2,000 species in Britain. Their sizes are various, the largest being about 2-½ in. long including its ovipositor. They are parasitic and lay their eggs in the nest or larvae of other insects, for ex-ample caterpillars, and are thus responsible for destroying vast quantities of insects, many of which are injurious to man.