50 INSECTS AFFECTING THE ORANGE . 



never long outlast the growing season. If not sooner exterminated bj 

 the attacks of enemies and parasites, the hardening of the tissues of the 

 bark and leaves gradually puts an end to their existence, and the young 

 of later generations must seek elsewhere for their support. 



Brood Periods. — Thus, in spring and early summer, when the Orange 

 renews its foliage and new growth is abundant, the increase of this in- 

 sect is most rapid, and the number and extent of its colonies often be- 

 come alarming. The month of June is generally the time of greatest 

 activity in this si)ecies. Later in the season the colonies dwindle and 

 become reduced to a few gravid individuals. The young are obliged to 

 wander far in search of bark sufficiently tender to be penetrated by 

 tlu'ir beaks. This can be found only upon the solitary shoots and vig- 

 orous leaders, which the tree in summer sends upwards from the trunk 

 or main branches below. It is not surprising, therefore, that very many 

 of the young lice hatched in summer perish from hunger, being unable 

 to find a spot penetrable by their beaks, or they fall a prey to numerous 

 enemies in their wanderings over the plant, and in fall and winter, as 

 a rule, only solitary individuals are met with. 



Excretion of Honey. — From minute pores upon the sides of the bodies 

 of these insects exudes a colorless nectar. This liquid may also be 

 ejected by them with considerable force, so that it falls upon the leaves 

 and parts of the plant at some distance away, and forms a sticky- coat 

 irig ; but it is never in sufficient quantity to form drops, as sometimes 

 happens in the case of other sucking-bugs which produce hone^' dew. 

 If not lapped up by other insects, the nectar attracts a bhick sugar 

 fungus {Capnodium citri), and the plant becomes coated with "smut." 



Attended by Ants. — Like all sluggish nectar producing insects, the 

 Lecanium hesperidum is attended by troops of ants, which feed upon 

 the sweet excretions, and not only clean the surface of the leaves about 

 the Bark-lice, but also lick the insects themselves, and with caressing 

 strokes of their antenna3 induce them to give out the liquid more 

 freely. Ants, therefore, are not enemies of this Bark-louse; on the con- 

 trary they are its friends, and afford it more or less i^rotection from the 

 attacks of certain enemies. The extent of their services to the Bark- 

 lice has been greatly exaggerated, however, and they cannot prevent 

 their destruction by internal parasites. 



As indicators of the presence of this Bark-louse, ants become useful to 

 the observing cultiv^ator, for if a tree is in the slightest degree infested, 

 and long before the colonies of Lecanium become destructive or even 

 noticeable, the tell-tale stream of ants ascending and descending its 

 trunk gives an infallible indication of the impending evil and guides 

 the eye to the secret lurking places of the pest. 



Parasites. — Colonies of the Turtle-back Scale are, however, seldom 

 allowed to dwindle and dissipate themselves solely by the action of their 

 own laws of growth and existence; they are subject to the attacks of 

 internal parasites which greatly hasten their dissolution. These para- 



