CULTIVATION OF THE ORANGE TREE IN SPAIN. 559 



ent ways, viz, by its force and by its temperature, the injury caused be- 

 ing greater or less according to the position in which the orchards may 

 lie. Xorth, northwest, and west-northwest winds are the most danger- 

 ous in certain places on account of their temperature, for as a rule they 

 dry up the extremes of the branches exposed to their influence, besides 

 which the shoots of certain species become unsound. Those that cause 

 most harm in the south of Europe, by reason of their impetuosity, are 

 the south, south-southwest, and south-southeast, according to the posi- 

 tion of the valleys. All these winds come with puffs of extraordinary 

 strength and destroy the branches unable to resist them. The only 

 remedy in these important occasions is to cut off everything that has 

 been destroyed and dried up. With the object of partially avoiding 

 these misfortunes, the custom of producing trees of shortened growth 

 has of late years vastly extended. 



The burning and rust The disease known as burning is due in great 

 part to the too abundant dews that fall here, which are evaporated with 

 an excessive rapidity by a burning sun. To the same cause may be 

 traced the disease vulgarly called " rust," or a class of mildew on the 

 leaves of the orange trees. This manifests itself on the fruit by a red 

 stain, which as it increases becomes much darker, and finishes by dis- 

 organizing tht pulp and rotting the fruit. The cleaning and pruning of 

 the trees is the best known method against this evil. 



Chlorosis. The chlorosis or yellowing of the leaves, and also the 

 withering, are generally attributed either to the superabundance of hu- 

 midity in the soil, to an excessive quantity of branches having but little 

 ventilation, to the want of iron in the earth, to a species of torpor in 

 the absorption of the mineral matters existing in them, and to the alter- 

 ation of the roots if old. The remedy to be employed to combat this 

 evil is distinct according to the cause by which it is produced. 



INSECT PESTS. 



These attack the roots, trunks, blossoms, and fruit, consequently 

 they are orgauical beings most pernicious to the trees, frequently caus- 

 ing exceeding harm on account of their extraordinary multiplication. 

 Of this numerous class of insects, the only descriptions which up to 

 date have proved enemies to orange trees, lemon trees, and others of 

 the Auranciacea family, which are cultivated here, are the coleopteral, 

 hemipteral, and dipteral. 



Coleopteral. This description contains more than fifty thousand spe- 

 cies, and only one is injurious to the orange tree, the same being called 

 Othiorhynchus meridionalis. This devours the leaves and tender shoots 

 of the orange tree, and is a class of beetle or winged insect. The 

 young insect is sufficiently perceptible, being about a centimeter long, 

 of reddish-black color, and with grooves on the elytron. During the 

 daytime it hides itself in the earth, where it should be hunted and de- 



