THE ORANGE. 637 



The decay and falling off of ripe oranges is sometimes 

 caused by attacks of members of the Mitre or Soldier-Bug 

 family, Asofus, which collect in large numbers upon the fruit 

 and suck its juices. These bugs usually breed upon cotton, 

 the cow-pea, and cucurbitacebus plants, migrating from these 

 to the orange-trees. They also puncture tender shoots, caus- 

 ing the ends to wilt and die. The best way to avoid them is 

 not to allow the plants upon which they breed to grow among 

 the orange-trees. It is well to observe here that strong soda 

 and potash sprays must be used with caution while the fruit 

 is small, or it may be rendered insipid and worthless from 

 the absorption of these substances, which neutralize its acids 

 and destroy the sprightly flavor. 



It is a common opinion that the harm done by a severe 

 winter has its compensations in the extinction of injurious 

 insects. There is little foundation for this belief. The 

 ravages of scale have often been more noticeable after rigor- 

 ous seasons than before ; so we may infer either that a lowered 

 vitality has rendered the trees more susceptible, or that the 

 friendly parasites have been diminished. 



DISEASES. 



Among diseases of the citrus, mal de goma is one of the 

 most serious. This is manifested by a gummy exudation 

 Ht the base of the trunk, followed by decay of the bark; 

 the malady gradually extending to the roots, and, if not 

 checked, often causing the death of the tree. It is supposed 

 to arise from a variety of causes, such as the close contact 

 of fermenting manures or corrosive substances; a rich soil 

 saturated with moisture, or highly nitrogenous fertilizers. 

 Sometimes when the cause ceases to exist the tree recovers 

 of itself. Removal of the soil about the diseased roots and 

 exposure to the air are recommended; also the cutting away 

 of diseased bark and wood and the application of a wash of 

 sulphurous acid. Trees on a friendly soil, nourished with a 

 well-balanced fertilizer, are seldom affected, and the sweet 

 orange is more susceptible than the sour or bigarrade. 



Limb-blight is an obscure disease, the origin of which is 

 still doubtful The leaves wilt, small twigs perish gradually, 

 and the tree falls into a decline and finally dies. There seems 



