59 



The Scale Insects are very harmful and many have 

 a very wide distribution, being so easily carried on 

 nursery stock and plants in general. 



They are most interesting insects on account of their 

 strange bionomics. 



The scale which we notice on the Rose in the case 

 of the Scurvy Scale is a product of the insect. Beneath 

 this the female lives and degenerates. She produces 

 eggs and from these hatch out little six-legged active 

 larvae which make their exit from beneath the scale. 

 They wander about and eventually fix upon some spot 

 on the Rose bushes. The young scale insect is pro- 

 vided with a long piercing mouth and this is inserted 

 into the plant. After this an excretion is gradually 

 formed over the back which, with the insects' cast skins 

 becomes the " scale." During its formation the active 

 six-legged larva degenerates into a footless fleshy mass, 

 the female. 



If the larva is destined to become a male a different 

 shaped scale is formed and the larva becomes a kind of 

 pupa a so-called propupa from which a winged insect is 

 produced. The male scale insect escapes from under the 

 covering and flies about. It has two wings and a long 

 projecting penis by means of which the females are ferti- 

 lized under their scales. 



Many scale insects reproduce like the Plant Lice r 



that is asexually. 



Such scales as the Brown Scales (Lecaniuni) have no 

 true " scale " the skin of the female merely hardens and 

 forms a house as it were for the eggs. 



