15 



do with imported selec 1 varieties of citrus plaits that th y are f ir more 

 liable 10 insect pests ihan our own native kinds, and it beh >ves the 

 grower to furnish himself with the necessary information and appara- 

 tus, tha*"- will keep down the p< sts as much as possible. 



Vory many districts in this I land are peculiarly suiied to the growth 

 of the orange and others of the citrus family, *nd it is advisable, when 

 possible, to select one of th se for the planting of a gr -ve, as the ci »s u* 

 we get to a natural soil for a plant, the greater ch nee has that pi nt of 

 flourishing, > nd the less likely is it to suffer from the attacks of disease 

 or pests 



But although the grower may be fortuna e enough to have h s trees 

 favourably situated, he wi 1 still find that they will be subject, more or 

 less, to the attacks of ins cts and other pests, a id in this paper we shall 

 consider the subject of employing, intelligently, methods that will effec- 

 tively combat the injuries done by them. It will be well first to take 

 into account the nature and method of such injury. 



In considering the damage done by insects proper, it must b? p tinted 

 out that the injury done to plants and trees is effected by two classes 

 of insects, termed by entomologists mandibulate or biting, and haustel- 

 late or sucking insects, and each of these has to b \ dealt w th by more 

 or less different methods. 



I The Mandibulate or Biting Insects. 



Under this heading are found those insect* that possess maniibles 

 or jaws with which they masticate the foliage of plants and trees and 

 bore into the bark and trunk tissues. This class comprises the beetles 

 in both 1 rval and perfect states, the caterpillars of b jth moths and but 

 terflies, and such insects as locus' s and ants. 



(1 ) Beetles. 



In the case of beetles the damage done may be two-fold, that is to 

 say, the imago or perfect beetle may be destructive to the foli tge of a 

 tree, while its larva or grub will be boring tunnels into the bark or 

 heart-wood. But it does not follow that an insect will be injurious to 

 the same species of plant or tree in both larval and perfect states. 



Hitherto investigations have proved that the larvae of two beetles 

 are injurious to the orange tree in this country. One of them, Oreodera 

 glauca, belongs to the tribe of Longicornes, a family famous for their 

 wood-boring proc'ivities. The damage done by the larva of this beetle 

 was investigated in 1895, when the trees in St. Ann and other parts of 

 the Island were observed to be affected. 



The larva was found to attack the trunk, making long shallow tun- 

 nels between the bark and the outer portion of the trunk, where oval 

 depressions were made in the outer wood in some places. 



The larva, which is about half an inch in length, is of a light cream 

 colour, except the jaws and first segment, which are brown. The body 

 is broadest anteriorly, narrowing gradually posteriorly, but thickens 

 slightly again towards the end. The sides of the body are clothed with 

 numerous fine hairs. 



The larva undergoes its metamorphosis in the shallow tunnels it 

 makes between the bark and the wood, when it finally e nerges a per- 

 fect beetle. More investigations are necessary to ascertain facts con- 

 cerning a fuller life history of the species, and more observations as to 

 the time of year that it generally makes its appearance. 



