THE EXTERMINATION OF PESTS 109 



and in both cases the attacked areas at first turn 

 yellow, then subsequently dry out, so that dead 

 patches are formed. At times the fan- shaped or 

 typical coconut leaves developed remain quite free, 

 even after the first leaves have been attacked, as 

 the plants seem to outgrow the effect of the scale. 

 Other sucking insects are the coconut snow scale 

 (Diaspis boisduvcdii), the coconut mealy bug 

 (Pseudococcus nipce), the black line scale (Ischnaspis 

 longirostris), the glassy star scale (Vinsonia stetti- 

 fera), and the white fly (Aleyrodicus cocois). 



These pests are more or less destructive, the 

 white fly being, perhaps, the most dangerous, as 

 it generally attacks young coconuts either in the 

 nursery or in the field. When nursery plants are 

 attacked, it is essential to treat them with some 

 insecticide before they are transplanted into the 

 field. The majority of these pests may be kept 

 well under control by means of an oily or soapy 

 wash, such as kerosene emulsion or whale oil soap, 

 while the glassy star scale and the black line scale 

 are more easily destroyed by a rosin mixture. 

 These washes are usually applied by means of a 

 spray pump or a garden syringe, but young plants 

 in the nursery may be treated by dipping them 

 into a tub or trough of suitable size, or by sponging 

 them with the insecticides. A practical bulletin 

 recently issued by the West Indian Government 

 sets out some valuable directions for the treatment 



