Gums, Resins, 



364 



I doubt if there is any difference in the yields of shade and sun-grown trees 

 of the same size. The temperature certainly affects the freedom of the flow of latex, 

 and on sunny plantations there is a great difference in the flow of latex at morning 

 and noon. This difference might not be so noticeable on a shaded plantation. It is 

 simply due to the evaporation of the watery parts of the latex, and not a greater or 

 less quantity of rubber-bearing constituents. 



The distance between the trees is another debatable question. The question 

 depends a great deal on how soon the plantation is to be tapped. Trees planted at 

 ten feet distance begin to crowd each other at about six years of age. If the planta - 

 tion is to be tapped at this age, 01 before it, this is a good distance to plant the 

 trees. When they get older, poorer and weaker trees can be bled out. The experi- 

 ment of planting four trees in a hole shows that it is possible for two, three, or even 

 all four of these trees to grow well and apparently not to hinder each other. If 

 these trees continue as they have begun, it seems to me that the way to grow the 

 largest number of good trees on a given piece of land would be to stake the land at a 

 distance of fifteen or twenty feet, and to plant a circle of eight or ten trees about 

 each stake. Any trees grown this way which did not keep up to the others should 

 be cut down, and by the time they are ready to tap there should be three or four 

 good trees in each group. This method would avoid one trouble which has shown 

 itself where one tree was planted to a hole, and that is that when the time to tap 

 came, many of the trees were poor and stunted in growth, and not worth tapping. 

 This irregularity of growth loses much time, and can be avoided where only the best 

 trees are allowed to grow. 



Another question which may prove of importance is that of branching. 

 Some planters claim that trees that put out permanent branches early grow 

 faster and yield better than trees branching later. Others claim that branch- 

 ing is not good for the trees. I believe that branched trees grow somewhat 

 faster because they get a larger leaf surface, but I do not think that this leaf 

 surface affects the amount of latex. Trees which are planted far apart branch 

 more freely and earlier than those planted close together. There also seem to 

 be more branches on sun-grown trees than on shaded trees. 



The buds of permanent branches may be forced and grown to branches 

 by cutting through the bark just above them, but this sort of branch does not 

 grow as fast as a natural branch. I believe that this can be developed, how- 

 ever, if desirable. It has been suggested that it would be better to grow branches 

 on the trees in such a manner that the tree could be ascended by tappers 

 without a ladder. The fact that some temporary limbs become permanent might 

 be investigated, and a way be found to make them become permanent at will 

 if desirable. 



INSECTS INJURIOUS TO THE CASTILLOA TREE. 



The insect which does the most damage to the Castilloa tree is the 

 borer. What the borer is, is still open to doubt, though in all probability it 

 is a long-horn beetle. It is possible that two or more species of long-horn beetle 

 bore into the Castilloa, and it may be that some species of moth does so also. 

 I have seen two sorts of larvae ; a small white one,* and a large one, reddish 

 in colour. The chrysalis of the white one is undoubtedly a long-horn beetle, 



* The beetle was Taeniotes scalaris, Fab. var. snturalis, Thorns. It belongs to the 

 extensive family of wood-boring Coleoptera known as the Longicornia. The species in question 

 extends from Mexico to Venezuela, with variation in the West Indies, Brazil, and in the Azores. 

 Drawings sent of larva and pupa or chrysalis were so characteristic of the Longicornia that, 

 taken in conjunction with information supplied, there need be very little hesitation in stating 

 that they were the respective stages of the above-named beetle. 



