140 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



removed. The trees are then stimulated into flower so as to produce fruit, 

 in the months of July, August, and September. If the trees have been 

 planted high and with a care to drainage, no manure beyond the occasional 

 mulching of weeds and bush will be required. 



Insect Pests of Citbus Trees. 



Citrus groves are seldom free from scale pests ; the trees may be often 

 noticed to assume a sickly yellowish appearance and die back. This may, 

 in some cases, be due to uncongenial conditions of the soil, etc. ; but in 

 most it is due to the attack of scale pests. The most injurious of 

 these are the orange snow scale, Chionaspis citri ; the small snow scale, 

 Chionaspis minor ; the orange mussel scale, Mytilaspis citricola ; and 

 the red spotted scale, Aspidiotus ficus. 



In dealing with the question of pests it should be remembered that it 

 is invariably the weakest trees that are most liable to be attacked. Every 

 effort should therefore be made to keep the trees in vigorous health. If 

 due attention has been paid to the proper planting and general cultivation 

 very little trouble will be experienced in this direction. The trees should 

 be kept properly thinned out so as to allow the free action of air, sun, and 

 rain ; this will go far to keep the trees free from scale pests. Scale pests 

 are always most abundant in overcrowded plantations. 



In some Citrus-growing countries the groves are freed from scale 

 pests by fumigating the trees with hydrocyanic acid and carbon bi-sul- 

 phide. In the 'West Indies spraying has always had the desired effect, 

 and is more readily carried out, needing only a suitable sprayer, of which 

 there are dozens on the market to suit all requirements. The Imperial 

 Department of Agriculture has issued a special pamphlet * dealing with 

 the scale pests of the "West Indies. In it six different recipes for washes 

 are given, each possessing its own special advantage. For general use the 

 following — if made in strict accordance with the instructions — cannot be 

 beaten or too highly recommended. 



Kerosene Emulsion (Hard Soap). 



Dissolve J lb. hard soap in one gallon of boiling water. Add 2 gal- 

 lons of kerosene to the hot liquid and immediately churn with a syringe 

 or force pump till the mixture becomes creamy. This is the stock 

 solution. Make up to 33 gallons. Use only rain water, or soft water 

 (i.e. without lime etc.). 



Gathering and Quailing. 



All Citrus fruits should be cut from the tree — not pulled — leaving less 

 than one-eighth of an inch of stem to each fruit. There are many forms 

 of fruit clippers on the market, one of the best being known as the 

 " Snyder's patent " ; this clipper is provided with a spring which holds the 

 cut fruit by its short stem. The blades are also rounded to prevent the 

 fruit from being punctured. Fruit growing on the high branches should 

 be gathered with a fruit picker ; this consists of a pole the end of which 

 is fitted with a hook clipper under which is attached a bag made of 

 * Scale insects of the Lesser Antilles, Part I. Pamphlet series, No. 7. 



