IN TOUCH WITH NATURE

Otago Witness, Issue 3867, 24 April 1928, Page 7

IN TOUCH WITH NATURE

THE HUMBLE BEE

By

J. DRUMMOND,

F.L.S., F.Z.S.

A question by Mr A. H. Waterton, Gladstone road, Gisborne, as to the habits tt of bees that attack his broad beans is > answered by consulting the extensive literature of the humble bee, Emerson’s " yellow-breeched philospher ” in poetry, Bombus terrestris iu the prosaic and precise language of entomology. Selecting a small cavity in the ground, and lining it with pieces of grass or moss, the queen bee forms a lump of paste, made of pollen moistened with honey collected from flowers. On top of the lump she builds a circular waxen wall. In this enclosure, about the size of a pea, she lavs the first batch of eggs. As soon as the eggs are laid, she seals them with wax by closing in the top of the wall. She keeps the eggs warm by sitting on them day and night except when she has to go out to collect food. To maintain animation and heat during the night and in bad weather, when food cannot be collected, she stores honey. To this end she makes in the entrance passage to her nest, detached from the pollen and the eggs, a large waxen honey pot. with a capacity of almost -a thimbleful of honey.

The young, hatching in about four days, eat the pollen on which the eggs were laid, and fresh pollen added by the queen mother. In addition, she gives them a liquid mixture of pollen and honey, which she prepares by swallowing honey and re- ~ turning it to her mouth and mixing it with pollen nibbled from the lump and chewed in her jaws. She makes a small hole in the waxen skin that covers the

young. Through her mouth she injects into the hole a little of the mixture, which the young devour greedily. As soon as she injects the food she quickly closes the hole. The young in this way are fed collectively when young, but separately when they -are large, a method described as a beautiful transition from mass provisioning to progressive provisioning.

The queen adds wax to the covering of the young as they grow. The lump has been expanding slowly, but it now begins to expand rapidly. In it there appear swellings, showing the position of each young. Two days later, 11 days after the eggs were laid, when the young are fully grown grubs, each spins an ovel pale yellow cocoon, thin and papery, but tough, in which it envelopes itself. The queen clears away most of the wax covering. The cocoons adhere to one another, but as those at the sides are higher than those in the middle, there is along the mass a groove. The queen sits in it, pressing her body close to the cocoons in the middle, and clasping with outstretched legs the raised cocoons ,at the sides. She spends most of her time in that posture. For half an hour or more she is almost motionless except for a rhythmic expansion and contraction of her abdomen, which is distended enormously. She usually lies in the groove facing the honey pot. In this position she may sip honey without turning her body, and she guards the entrance to her home.

Workers take in hand the collection of

and nectar and the enlargement of *lhe colony. Remaining in the nest, the queen gives herself up to laying eggs, vjjhile the workers protect the best, build new cells, feed fresh broods of young, and make honey pots and receptacles for pollen, or store honey and pollen in cocoons from which workers have-emerged. Some grubs hatched from the fertilised eggs laid by the queen are fed liberally, and develop into queens. Emerging from their coco Ons in the late summer, these mate with males, disperse, and establish new colonies in the following spring.

Attention has been drawn to the fact i that the structure of the workers in a j . colony is the same as the structure of the queens. They are fed inadequately in their grub stages,- and are smaller than ; the queens. They are regarded as the re- ! suit of a high reproductive activity on the queen’s part under unfavourable feeding -conditions that do not permit them to attain full stature. Humble bees are primitive. As a queen, while establishing the community over which she reigns, behaves first like a solitary bee, but later enters a stage of progressive provisioning, humble bees are believed to represent an interesting transition from the — forms of bee to the social forms. ■ The’ r- honey bee is the most highly socialised form. All solitary bees make earthen or resin cells. • The humble bee’s' cells are like the cells of solitary bees, except that

they are waxen, but even, in the secretion of the wax humble bees represent primitive conditions. There are more species, or kinds, of bees than is known generally. Entomologists arc acquainted with no fewer than 10,000 species. In Europe alone there are about 2000 species. To entomologists, bees are merely a group of wasps, which have become strictly vegetarian, and feed exclusively on the pollen and nectar of fio.vcrs. They arc flower wasps.

The close relationship between bees and flowers has left its stamp on every organ of the bees, and on most of their habits. Many flowers, responding, have mo., ueii their structure, their arrangement, their colours, and their perfumes to suit the bees, and to ensure the flowers’ crosspollination. This, at least, is a theory accepted by some botanists. Bees have developed structures particularly for collecting and carrying nectar and pollen, “ the of fructifying gold,” as Russell Lowell describes it in one' of his study-window essays. Their mouth parts are adapted to lapping or sucking honey. Nectar, while it is transported to a bee’s nest, is stored in an enlarged bag-shaped part of the alimentary tract, whole walls are furnished with muscles that enable the bee to regurgitate the nectar. In the bag, the nectar is mixed with ferment, and undergoes a chemical change. The result is honey. Most bees have their bodies densely covered with hairs, branched and feathery. These hold grains of pollen until a bee sweeps them together with its legs. Some bees carry pollen baskets. Bees

with short tongues are more primitive than bees with long tongues, provided at the tip with a spoon and swollen hairs. The humble bee and the honey bee visit many flowers. Some bees visit the flowers of only a few plants, or the flowers of a single species. New Zealand, comparatively poor in its insect fauna, has about 20 species of bees of its own. All these are short-tongued, and theritfore primitive. Members of one New Zealand family, smOoth-bodied, flowerhaunting, almost completely black, have no device for collecting pollen, but sweep it into their mouths with their legs. Dr R. J. Tillyard states that the _ honey bee, by starting work earlier and in less bright sunshine, has driven away many of New Zealand’s native flower-haunting bees. Four species of humble bee in New Zealand were introduced to fertilise the red clover, but the tongue of the most plentiful of these, Bombus terrestris. is not long enough for the purpose.

When Mr W. Chappell, headmaster of the Ngatea District High School, Thames County, was felling large Pinus insignis trees at Northcote, he saw several insects on the wing that attracted attention by their size and their brilliant colours, and by the fact that they seemed to be interested in 'the trunks of the trees. On the logs being cut, there were found in them many perfectly round holes, into which a slate pencil could be inserted. In some of the holes there were cocoons. In others there were perfect insects,'similar to those seen flying near the trees. The perfect insects exposed when the logs were cut open were alive, with their tails towards the openings of the holes. Apparently they had developed from the grub stage in the holes made by the grubs,, and were ready to emerge into the air by backing out tail first. They are particularly good specimens of the notorious horntail borer.

Recent notes on white ants have reminded Mr Chappell that three years ago he found colonies of these insects in the blocks and the adjacent timber of the Methodist Church at Birkenhead. It had been necessary to remove the foundations of the building. Examining the puriri blocks taken out. he found that round ones, cut from whole branches, not split timber, were affected most. Split puriri blocks were comparatively free from the white ants. The round blocks had contained pith and sapwood. These would rot first, and Mr Chappell concluded that the insects followed the dot. instead of causing it. The round blocks were affected most in their centres, and in the outer wood. It seems to Mr Chappell , that the insects ascended from the ground level, and that they had a preference for i the puriri. They attacked the_kauri plates only -where these had' rotted on account of contact with rotten blocks below. For this reason,- Mr Chappell ■ strongly favours the use of concrete blocks.