G8 SYLVICULTURE IN THE TROPICS pt.i 



the attacks of injurious insects or other animals, invite 

 the presence of warlike ants by providing them not 

 only with dwellings in the shape of hollow stipular 

 thorns (as with Acacia Seyal var. Fistula of Africa 

 and A. cornigera of America), or hollow internodes 

 (such as Humboldtia, Triplaris, etc.), or hollow shoots 

 (such as Cecropia), but also with food. In the case of 

 the last-named tree, it is with other ants the leaf-cutting 

 ants that the defenders have chiefly to deal, but all 

 those who have dwelt in the Tropics know to their 

 cost what it means to disturb the pugnacious ants 

 dwelling in certain trees. There are several other 

 insects which are carnivorous and, by preying on those 

 which do damage to the forest, are the real friends of 

 the forests, together with the birds and other animals 

 which devour the plant pests. Among the insects most 

 useful may be mentioned the ground and tiger beetles 

 and the ichneumon wasps, and, for destroying Coccidae, 

 the lady-birds. Further mention of these useful animals 

 will be made as occasion occurs. 



To turn to forest destroyers : they are so numerous 

 and so varied that it is a wonder that there are any 

 forests left to fight them, and the plant enemies which 

 also attack them. But notwithstanding the marvellous 

 recuperative forces of Nature many a tract has been 

 deforested and denuded, and barren expanse meets the 

 eye where formerly leafy trees cast a grateful shade 

 over the ground. 



First of all there are the insects, among which the 

 Coleoptera, Orthoptera, and Lepidoptera are probably 

 the most destructive, although the Neuroptera and 

 Hemiptera are also the cause of much damage. The 

 Governments of tropical countries are becoming aware 

 of the damage done by insects not only to forest crops 

 I nit to cultivation, and to the lives of animals and men, 

 and several of them have already appointed entomolo- 

 gists in order to study these pests. With the help of 

 these as well as of foresters, who make the study of 

 insects affecting forest life their particular hobby, 



