REPORT OF THE ENTOMOLOGIST. 



367 



both of scalc-inscct and rust-mite, that of transportation by spiders is 

 the mast important, the most constant, and regular, The spiders bear 

 with them upon their hairy bodies the young bark-lice and the adult 

 mites, conveying- them in their own migrations to distant points, and col; >- 

 nizing them under their protecting web whenever they chance to se- 

 lect the leaves of a citrous plant as their resting place. 



And here is found the solution of that puzzling inlluence of the wind 

 so often remarked in the case of scale-insects, and which has led many 

 to believe that they aro disseminated directly by this agency, and 

 therefore spread most rapidly in the direction of the prevailing currents. 



Spiders of the web-making kinds aro necessarily dependent upon the 

 wind in making long voyages. The warm southeasterly winds of spring 

 excite in them the migratory instinct, and at a time when the orange- 

 trees are swarming with the quickened lite of scale and mite, from a 

 thousand projecting points of branch or leaf, the spiders are sending 

 out their lines of rapid transit, and are bearing with them u on the 

 wings of the wind" the seeds of mischief to the orange-grower. 



RAVAGES OF THE RUST-MITE. 



TJie Mite known only upon Plants of the Citrus Family. — The Eust-mite 

 attacks indiscriminately the various species of Citrus in common culti- 

 vation, but has not been observed to feed upon plants of any other ge- 

 nus. It is found upon the Lime, Lemon, Citron, Shaddock, Bigarde, and 

 Tangerine, and none of the varieties of the Orange are known to b^ in 

 any degree exempt. 



Upon the leaves and fruit of all these species of Citrus, the effects of 

 its attack are essentially the same, although the rust is most notice- 

 able on the sweet and bitter Orange. 



Effect of Attacks upon the Foliage. — Like certain internal animal para- 

 sites, which feed only upon the fat of their hosts, and do not touch its 

 vital organs, the mite does not destroy the vital functions of the leaf. 

 The chlorophyl is untouched, and the plant is robbed of a portion only 

 of its essential oil. The leaves never drop, no matter how severely at- 

 tacked, but there is loss of vitality, and the growth of the plant is 

 checked. This is especially noticed in young trees, which are frequently 

 overrun by the pest in early summer, and during the remainder of the 

 year make little progress. 



The foliage of affected trees wears a dry, dusty appearance, and loses 

 color. The leaves are without gloss, and become slightly warped, as in 

 droughts. 



Rusted Fruit. — If severely attacked by rust before it has completed 

 its growth, the orange does not attain its full size. Very rusty fruit is 

 always small. Its quality is, however, improved rather than deterio- 

 rated. The toughened rind preserves it from injury and decay, prevents 

 evaporation from within, and carries the ripening process to a higher 

 point. 



Eusty oranges can be shipped without loss to great distances. They 

 keep longer, both on and off the tree, and when they reach the North- 

 ern markets are superior to the bright fruit in flavor. Consumers not 

 being aware of this fact, however, prefer the latter, and the reduced 

 price of the bronzed fruit more than offsets to the producer its superior 

 keeping and shipping qualities. 



Introduction and Spread of the Mite. — Of the origin of the Eust-mite, 

 whether native or introduced, we as yet know nothing. As far as 

 has been observed, it is not found upon the wild orange trees in Flor- 



