The Bulletin. 9 



rule among insects, which in most cases lay eggs. At Raleigh, breeding 

 begins from March to May, depending on season. After crawling for a 

 short time the young insects insert their beaks and begin to feed. Then 

 the skin is shed and the scale begins to form over the body and the 

 insect is thus confined at that spot. When the skin is shed, the legs, 

 eyes and antenna (feelers) are shed oif with it, and thereafter the 

 female insect is always eyeless, legless and wingless; simply has the 

 organs for taking and digesting food and for reproduction. It takes the 

 females from thirty to forty days to reach maturity and the males not 

 quite so long. The male develops finally into a tiny, yellowish, two- 

 winged flying insect. Strange to say, the mature male insect has no mouth 

 for taking food, the position of that organ being occupied by an extra 

 pair of eyes. This renders it more proficient in finding mates and thus 

 aids in the multiplication of the species. In this State there are probably 

 from five to eight generations in a season, and the number of progeny 

 of a single fertile female, in the course of a season, if there were no fatal- 

 ities, w^ould by actual calculation number among the billions. Remem- 

 bering that many of the insects are destroyed by enemies as described 

 later, we can still see that it is no wonder that a tree that becomes in- 

 fested while young is almost sure to die unless thoroughly and persist- 

 ently treated. The most active period of increase is during August and 

 September. 



HibGrnation. — When really cold winter weather comes on the insects 

 cease to breed. During the winter the adult insects nearly all die, so 

 that it is mostly the partly grown insects that pass the winter. How- 

 ever, in warm winters we have knowm the insects to breed even in mid- 

 winter on warm days in the warmer sections of the State. 



How Does the Scale Spread?— We have seen that the insect can 

 only crawl about for a few hours after birth, and that therefore it could 

 only spread very slowly, and only during the breeding season, if it were 

 entirely dependent upon its own powers. As a matter of fact, however, 

 there are various outside agencies which aid them in spreading into new 

 trees, new orchards and new localities. Chief among these outside agen- 

 cies are: (1) Wind, (2) Birds, (3) Insects, (4) Commerce in nursery 

 stock. These, with its own limited natural powers, constitute its prin-' 

 cipal methods of spread. We will consider each of these separately, con- 

 sidering first its natural powers. 



Natural Spread. — If one of the young insects should start out as soon 

 as born and run as rapidly as it could until it became necessary for it to 

 settle down and begin to feed, it could only travel a short distance, per- 

 haps one or two rods. It is evident, therefore, that the vast majority of 

 the young insects settle on the same tree on which they are born. If the 

 trees are so set and pruned that the branches of separate trees do not 

 interlock, it will be almost impossible for the young insects to get from 

 one tree to another of their own accord, and this is an important point, 

 for the spread of the scale in thickly set orchards may be very materi- 

 ally lessened by keeping the branches so pruned that they shall not reach 

 from one tree to another. But in spite of this the insects will usually 

 spread to the other trees more or less rapidly by other means. 



