116 



Wellesley where Mr. D. Logan planted about 2,000 young trees nine 

 months ago and the growth is very satisfactory. From planters in 

 Selangor I hear that the prospect is most encouraging, the trees making 

 very rapid growth. It is evident however, that the land selected should 

 be sufficiently drained to prevent the young plants being submerged, 

 for in one spot where this has happened at Bertam, many have died and 

 those that are alive do not look nearly so well as others on slightly 

 higher land. 



SCALE INSECTS: REMEDIAL MEASURES AND 

 INSECTICIDES. 



By E. E. Green, F. E. S. * 



Id the following pages I have endeavoured to bring together scat- 

 tered information on the various methods that have been employed in 

 dealing with insects pests of the family Coccidae, Though such treat- 

 ment may in many cases be found suitable tu insect pests of orlw fami- 

 lies, I do not propose to give here a general treatise on insecticides, but 

 to confine myself to measures applicable to the subject of the present 

 work. 



Little or no originality can be claimed tor the following remarks. 

 They are very largely compiled from the published work of trained en- 

 tomologist< (chiefly American) in different parts of the world. America 

 has long been in the forefront in the practical application of economic 

 entomology. 



Remedial measures may be discussed under two main headings : 

 Prevention and Cure. The former, being by far the more important, 

 will be dealt with first : — 



Preventive Measures. 



Of first importance among preventive measures, I would place 

 Quarantine Regulations. It is a fact, repeatedly demonstrated, that 

 imported pests are the most serious. An insect may attract little or no 

 attention in its original home, where it is kept in check by its own 

 natural enemies, a system recognised as ' the Balance of Nature.' But 

 take it away from its home; place it in a congenial climate with an 

 ample supply of suitable food, and it will multiply without the checks 

 that have prevented its increase in its original habitat. The very fact 

 of extensive damage by any insect may of itself almost be accepted as 

 proof of its foreign origin. Looking through the list of the different 

 scale-insects occurring in Ceylon, I find that all the more trou- 

 blesome species have been previously described from some other 

 country, and are. therefore, presumably imported insects. The 

 home of the v Lantana bug' (Orthezia insignis) is now supposed 

 to be some where in South America ; and there is evidence in 



From " The Coccidas of Ceylon," Pt. II., Dulau & Co., LondoD. 1899. 



