SCALE INSECTS 



nest will require a supply of 100,000 insects a day during the 

 season. 



It is quite common to find ants crawling about on the out- 

 side of the large heads of the Garden Centaury and a few- 

 other Composites. If one looks carefully, one finds that 

 there are streaks of honey to be seen coming from the scales. 

 The honey is not produced in the flowers, and seems at first 

 sight to be of no use at all so far as the plant is concerned, 

 but that is very far from being the case. Here comes a cock- 

 chafer or other destructive beetle, intent on absolutely 

 devouring and destroying the young flowers. At once the 

 pugnacity and wrath of the ants are aroused. They take 

 up a menacing and ferocious attitude, and the cockchafer 

 passes to some other plant.^ 



Such honey-glands found on the leaves and not connected 

 in any way with the flowers, are more common than one 

 would think. Even the common Bracken produces curious 

 honey-secreting hairs when it is in a young condition. 

 These attract ants which drive away caterpillars and other 

 dangerous insect foes. 



Many very dangerous insects are too small for birds, and 

 can only be dealt with effectually by insects or fungi. Of 

 these perhaps the most dangerous are the "scale" insects. 

 The best-known one is very like a minute mussel shell. It is 

 about one-quarter to one-third of an inch long, and can be 

 sometimes found in quantities on apples ; they are generally 

 collected round the stalk. The mother insect has this scaly 

 back, and lies down and dies on the top of her eggs, so that 

 her scaly corpse forms a roof and a shield for her young 

 ones. Like all pests of this sort, these creatures increase 

 very rapidly. 



1 Kerner, Z.c, vol. 2, fig. 264, p. 242. 

 288 



