200 OTHER DENIZENS OF THE WOODS 



found Pyrrhocoris apterus, which feeds on dead insects and the young leaves 

 and fruit of the lime. This common insect, found all over Europe, is about § of 

 an inch long, and in colour black and red. On the stems of trees, especially 

 birches, where it crawls about in search of caterpillars, may often be seen the 

 red-legged tree-bug (Tropicoris rufipes), which is rather larger, and yellow and 

 red in colour. Such raspberries, cherries, and other small fruit as have an 

 unpleasant taste, owing to a bad odour about them, have probably been infected 

 by the berry-bug (Pentatoma baccarum), which is about the same size, and brown 

 and white in colour. 



To another section of the Rhynchota belong the cicadas (Cica- 

 didce), which are mainly confined to subtropical and tropical countries, 

 and in Europe are seldom found beyond the vine-growing districts. In many parts 

 of the Continent one species (Cicada concinna) is, however, heard on sunny days 

 and warm nights till late in the autumn, notably at Erlangen, Heidelberg, in 

 Franconian Switzerland, and other south German localities, and also on the 

 Drachenfels near Bonn, where it often occurs in such multitudes that the chorus it 

 produces affords some idea of the noise made by the large cicadas of the south. 

 These insects bore twigs with their beaks to suck the sap, which continues to run 

 after tapping, and dries, and in many districts is collected as manna. Manna-sugar 

 is present in many plants, such as beet, asparagus, onions, celery, and the ash ; it is 

 used commercially as a drug, being mainly obtained from the manna-ash (Fraxinus 

 ornus) in Sicily and Calabria, by means of horizontal incisions in the bark. The 

 cicada inhabiting the manna-ash (C. ami) is 1| inches in length, yellowish, and 

 spotted with brown; in central Europe it is unknown farther north than the 

 Thuringian Forest. Leaving the higher trees of the forest, we frequently find on 

 hazel-bushes the species known as Centrotus cornutus, an insect about half an 

 inch long, dark brown with yellowish wings and a hooked thorn on the back ; 

 and on rose-bushes that active jumper Typhlociba rosai, about a quarter as long, 

 yellow, with white wings striped at the tips. 



Especially rich in species and individuals is the family of bugs 

 commonly known as plant-lice, or aphides. The males and females of 

 these insects are distinct in size and colour, and change their hue according to season 

 and food : they emit a honey-like juice of which ants are particularly fond. This 

 juice flows from trees, in consequence of the bite of the aphis, covering the leaves and 

 stalks, especially in July, with a shiny coat like varnish, commonly called honey-dew, 

 and, when mixed with the discarded skins of the insects, known as meal-dew. The 

 belief that honey-dew and meal-dew — names that are also applied to certain 

 funguses which live on leaves — fell from the air during thunder-showers is 

 presumably based on the fact that plant-lice multiply in the greatest degree when 

 the weather is damp and warm. It has, however, been recorded on several occasions 

 that plant-lice have fallen from the air in large numbers. They are extremely 

 prolific, owing to their being capable of reproduction when only a few days old. 

 Each female brings about ninety young into existence at a time, and can, after five 

 generations, have a progeny of more than five millions. For this increase no 

 males are required during the greater part of the summer; and the extremely 



