CHAMBERS'S INFORMATION FOR THE PEOPLE. 



upon them numerous delicate striae, which break 

 up the rays of light, and so cause the iridescent 

 appearance. The Lepidoptera feed upon fluid 

 nutriment. The larvae are known as Caterpillars, 

 which have a masticatory mouth ; and when they 

 attain their full size, they spin around their bodies 

 a case or cocoon of silk, in which to spend their 

 life as a pupa or chrysalis. From one species 

 we derive the silk which is woven into one of 

 the most elegant kinds of cloth. The glutinous 

 matter of which the threads are composed is 

 secreted by glands analogous to the salivary 

 glands. It is forced through a small opening at 

 the end of the lip, and hardens as it is exposed to 

 the air. Some species, however, form no cocoon, 



Argynnis Paphia. 



but hang in the pupa state from some lofty place. 

 At the proper time, the perfect insect bursts from 

 its case, to spend a brief, gay existence in the air, 

 to lay its eggs, and then perish. 



Family Papilionida (Butterflies) are also called 

 Diurna, because they fly about during the day, 

 and are distinguished by the extraordinary beauty 

 and variety of the colours which adorn their wings. 

 Their antennae are almost always terminated by a 

 knob. Over 2000 species exist in Great Britain 

 alone ; but it is in tropical climates where these 

 most beautiful of all insects attain their greatest 

 size, and exhibit the greatest variety of absolutely 

 dazzling hues. 



Family Sphingidce (Hawk Moths), or Crepuscu- 

 laria, so called from their general habit of flying 

 abroad at twilight Their colour is duller than 

 the butterflies, and when flying, they make a 

 humming noise. The Death's-head Moth (Acher- 

 ontia atropos) has a skull-shaped patch of colour 

 on the back of the thorax, and its sudden appear- 

 rance has been regarded as an evil omen. 



Family Noctuina, or Moths Proper, fly only by 

 night, and are of a dull style of colouring. This 

 family includes the Silkworm (Bombyx mart), a 

 native of China. It was imported into Europe in 

 the reign of the Emperor Justinian, in 550 A.D. 

 The caterpillar of the silkworm, when it has 

 attained its full size three inches long and be- 

 fore it passes into the chrysalis stage, spins for itself 

 an oval ball or cocoon composed of a long slender 

 filament of yellow silk. After emancipating itself 

 from its silken prison, it seeks its mate. In two 

 to three days afterwards, the female having depos- 

 ited her eggs, from 300 to 400 in number, both 

 insects terminate their existence. 



ORDER 10. tJymenoptera (or Membrane- winged) 

 in which the wings are four in number, of a mem- 



148 



branous texture, with few nervures, the anterior 

 being larger than the posterior pair ; they are 

 sometimes absent. Mandibles are always present, 

 and the arrangement of maxillae and labium into 

 a suctorial organ has been described already. 

 The females are furnished at the extremity of the 

 abdomen with an ovipositor, and in some species 

 (Bees, Wasps) this organ is modified, so as to 

 constitute a most formidable offensive weapon. 

 Many possess instinct of a very high degree, and 

 some live in social communities, as the Bees and 

 Ants. This order includes the following families : 



Tenthredinida (Saw-flies). The females have 

 an ovipositor which combines the properties of a 

 saw and a file. With this, they bore a series of 

 holes in trees, depositing in each an egg, with a 

 drop of frothy liquid, which seals up the hole. 

 The larvas have from ten to sixteen feet, and so 

 are easily distinguished from the caterpillars of the 

 Lepidoptera, which they resemble. 



Ichneumonidce (Ichneumons). These are para- 

 sitic, and insert their sting into and deposit their 

 eggs in the larvae of other insects, where the 

 young, when hatched, find sufficient nourishment. 

 The grub ultimately falls a victim to its ravages ; 

 though they carefully avoid injuring the vital parts 

 of the larva on which they prey. Scarcely an in- 

 sect exists which in the larval stage is exempt 

 from attacks from one or other species of this 

 family, so numerous are they. 



Cynipsida (Gall-flies). These insects deposit 

 their ova in living trees, and by their presence 

 give rise to the formation of excrescences, called 

 galls, such as those on the leaves of the oak-tree. 

 The larvae feed on the interior of their habitations, 

 where they remain for five or six months. Some 

 undergo their metamorphoses within the galls, but 

 others escape through small apertures to undergo 

 that change. Galls are imported from the Levant, 

 and are used in the manufacture of writing-ink 

 and dye-stuffs. 



Formicidce (Ants), so celebrated for their in- 

 dustry, live in societies, often of great extent, 

 consisting of three distinct kinds of 

 individuals males, females, and neu- 

 ters. The males are winged during 

 the whole of their existence, the females 

 during only part of their mature state. 

 At a certain period in summer, the Neuter Ant 

 males and females appear in large (Worker), 

 quantities, quit the nest, and copulate 

 in the air, when the males speedily die. The 

 females then lose their wings, fall to the ground, 

 and are picked up and carried to the nest by 

 the neuters, when they become the queens of 

 future societies. The neuters form the great 

 bulk of the community, and upon them depends 

 the entire labour of the community. They are 

 really females in which the sexual organs are un- 

 developed from the difference of food in the larval 

 stage. They construct the nest, and attend upon 

 and feed the young larvae. Like the females, 

 they possess a sting. The larvae of ants, unlike 

 those of bees, are never inclosed in cells. The 

 food of most species of ants consists chiefly of 

 aphides or plant-lice. Some species in India 

 and in the south of Europe hoard grain and 

 other seeds. The nests of ants consist of numer- 

 ous chambers communicating by winding and 

 tortuous passages, and they are sometimes exca- 

 vated in the ground, at other times in the trunks 



