322 The Spraying of Plants. 



tion. The insect is pale green in color, and is marked above by 

 six small dark spots. It feeds upon the juices of the plant, 

 and increases with such rapidity that, unless checked, the foli- 

 age soon becomes ruined. Ten days is the estimated time for 

 maturing the insect from the egg when conditions are favorable. 

 The name " spider " has been applied to the mite on account of 

 its habit of spinning a fine thread which often entirely covers 

 the infested parts. 



Treatment. The pest is held in check by abundant rains, 

 showing that it does not relish water any more than its relative, 

 the red spider of greenhouses. It is also easily destroyed by 

 kerosene emulsion, whale-oil soap, and if the trees are thoroughly 

 and forcibly sprayed with clear water, it will have a decided 

 effect in clearing the foliage of the insect. 



Rust-mite. The rusty appearance of oranges is caused by the 

 work of a minute yellow animal, a true mite. It lives upon the 

 essential oil which is found in all parts of the orange tree, suck- 

 ing it out by means of a beak. On the fruit this causes the 

 familiar browning of the orange. 



Treatment. As the eggs, molting young, and adults are found 

 upon the trees at all seasons of the year, no definite direction 

 can be given which will apply to every district. All applica- 

 tions should be repeated at intervals of a week or ten days, so 

 that the young may be destroyed before they mature. Spraying 

 the trees with sulphur suspended in water is one of the best 

 remedies, as the fumes are deadly to the insects. Whale-oil 

 soap solution, made by dissolving one pound of the soap in ten 

 gallons of water, is also effectual. 1 



Glover's Scale ; Long Scale ; Oystershell Scale (MytUaspis 

 Glover ii, Packard). Description. The eggs of this insect hatch 

 early in spring, the young larvae being yellowish purple in color. 

 These almost immediately begin to secrete a cotton-like covering 

 which extends over the entire body in about a week. The first 

 molt takes place about three weeks after the eggs hatch, and 

 the covering of the insects from that time on is penetrated with 

 difficulty by insecticides. There are three periods when the 

 newly hatched scales are most abundant : in March, in June and 

 July, and in September or October, and each generation soon 



1 For detailed experiments, made by H. G. Hubbard, see Ann. Rep. 17. S. Com. 

 of Agric. 1884,361. 



