636 THE ORANGE. 



causing them to drop, thus retarding the growth and develop, 

 ment of fruit aad lessening the vitality of the tree. Water is 

 the bane of these insects, which increase marvellously fast in 

 times of drought, and correspondingly diminish during rainy 

 periods. There is one species that thrives in the wet season. 

 Kerosene emulsion and the sulphur or soda sprays are effec- 

 tive destroyers. A minute lady-bird, scarcely visible to the 

 naked eye, has been found preying upon the red spider. 



The Red Scale, Aspidiotus fieus, and Long Scale, Mytilaspis 



Gloveri, which fasten to the bark and leaves and feed upon 



' the sap, are chiefly vulnerable when their larvse are in motion 



in March or April, June or July, and September or October, 



and may be checked by the same preparations. 



The White Fly, Aleyrodes citrifolii, has lately wrought much 

 harm in the Florida groves, particularly in the far south. 

 This insect breeds three times during the year, and should be 

 attacked soon after hatching. The rosin washes are. most 

 effectual against it. Lately there has appeared a parasitic 

 tungus, Aschersonia, which attacks and destroys the larva? of 

 the white fly. Trees which had suffered from the pest for 

 years and nearly succumbed are now recovering since the 

 spread of this fungus among them, which, it is thought, will 

 finally put an end to the trouble. 



The insects above mentioned have proved the most trouble- 

 some of any hitherto dealt with. There are other scales, of 

 minor importance, which may be fought in the same manner 

 whenever numerous enough to be harmful. The most effective 

 method of killing scale or other insects, so far discovered, is 

 by fumigation with hydrocyanic gas, as practised in California. 

 The gas is generated under a tent enclosing the tree, and an 

 exposure of half an hour has been found to destroy all insect 

 life. The trouble and expense of applying may prevent its 

 use except in desperate cases. 



The well-known Mealy Bug, Coccus adonidum, often seen 

 upon the pineapple, and generally to be found in the blossom- 

 end of a ripe pomegranate, has sometimes been quite trouble- 

 some to the orange. Besides weakening the tree, most of the 

 insects spoken of leave a smutty deposit, sometimes to such 

 an extent as to unfit the fruit for market unless previously 

 . cleaned, which involves much time and labor. 



