THE TRUE LICE. 



117 



form attach themselves by the rostrum to some juicy part of the plant; while the male larvae, which 

 frequently betake themselves to the more solid portions, undergo a process of change which is 

 peculiar to them among the Rhynchota. Beneath the scale-like skin of the larva the male 

 insect becomes converted into a resting pupa, and the first indication of his being ready to emerge is 

 the protrusion, from the 

 hinder part of the pro- 

 tecting scale, of a pair 

 of tine white caudal 

 bristles. The male then 

 soon makes his escape, 

 coming out of his case 

 backwards, so that the 

 two delicate wings with 

 which he is provided 

 are pulled up completely 

 over his head. He is a 

 rather elegant creature, 

 with a pair of perfect 

 wings, the hind wings 

 being represented by a 

 sort of halteres ; but his 

 partner, making good 

 use of the ample supply 



of nourishment at her COCHINEAL INSECT. 



command, has in the 



meantime become rather obese, and may be found adhering to the shoots of the plant, with scarcely 

 any recognisable trace even of the original segmentation of her body. In most cases, in fact, the 

 females might be taken for excrescences of the plant rather than insects. When numerous, the females 

 often do much injury to cultivated plants and trees. Thus Lecanium hesperidum attacks the orange, 

 and another species (Coccus adonidum) is often mischievous in hot-houses. They are known to gardeners 

 as Scale- insects, or, shortly, as "the Scale." The female, after fertilisation, deposits her eggs between 

 the lower surface of her body and the surface on which she rests. As the eggs are extruded the body 

 of the mother shrinks, until her dried integuments serve as a protective covering to the mass of eggs. 



If some of the species are injurious, others have proved of much value to mankind, such as the 

 true Cochineal insect (Coccus cacti], a native of Mexico, which furnishes the most valuable and 

 durable red dye that we possess, and the Lac insect (Coccus lacca), an East Indian insect, which 

 produces the well-known lac-dye, and also by its punctures causes the exudation from the trees of the 

 resinous substance shellac. The former feeds on a cactus, the latter on the Indian fig and some other 

 trees. Porphyrophora polonica lives on the roots of a Scleranthus in Germany and Poland, and was 

 much esteemed as a red dye before cochineal was generally known in Europe. Many of these insects 

 show a white coating on their surface, and this attains a remarkable development in a peculiar species 

 which is common on nettles, and called Dorthesia urticce. The female is so covered with the white 

 secretion that it looks like a little piece of chalk. The female of this insect is active throughout its 

 life. In Aleurodes chelidonii both sexes possess four wings, and this insect forms a very clear 

 transition towards the Aphides. It is common on the greater celandine (Chelidonium majus). 



SUB-ORDER III. PEDICULINA. 



The PedicrJina, or true Lice, form the last and lowest group of the Rhynchota, of which they 

 must be regarded as very degenerate forms. They have no wings ; the thorax is small, and its 

 segments are not very distinct ; the abdomen is oval, and composed of nine segments ; the antennse 

 consist of five joints ; the eyes are small and simple ; and the six legs are well developed, with two- 

 jointed tarsi, the first joint being small, and the second larger and claw-like, and folded back upon the 

 first like the blade of a knife upon its haft. The mouth consists of a fleshy sheath (the labium), 



