October, '17] DUNN: cocoanut-tree caterpillar 483 



When trees are infested with these pests the most practical method 

 of disposing of them is by going up in the trees by means of long ex- 

 tention ladders that will reach to the tops of the trees and cutting down 

 the nests without disturbing the occupants. They can then be 

 crushed with heavy mortars, or a better way is to throw the nests 

 containing the caterpillars on a hot fire. They may also be killed by 

 dipping in a strong contact insecticide. 



While cutting out the nests is about as troublesome as spraying, if 

 done at the proper time it is only necessary to be performed once 

 during a season and will give the most reliable results. 



When spraying is the method employed every tree would have to 

 be gone over in order to be effective and to prevent the caterpillars 

 from leaving a sprayed tree and emigrating to one that was not treated, 

 while nest removals require attention only to the infested trees that 

 may be found. The principal point to be observed in cutting out the 

 nests is to be on the lookout and remove them at the proper time. 

 They should be removed early and before the caterpillars have become 

 fully grown. If they are neglected until the caterpillars have become 

 mature many will have left to pupate by the time the nests are removed 

 and naturally will develop into adult butterflies and propagate the 

 following season. 



Cutting down the nests is the method that has been adopted with 

 the cocoanut trees in the Ancon Hospital grounds and it seems to 

 have proved effective. 



Banding the trees with a sticky substance may prove to be of some 

 value in preventing the young caterpillars that emerge from eggs that 

 are deposited in places other than the trees, from gaining access to 

 them. This may be done by painting a ring about 18 inches wide 

 around the trunk of the tree at some distance from the ground with a 

 thick coat of tar or other sticky material of like nature that is suffi- 

 ciently waterproof to withstand the heavy rains. This should also 

 be done at the proper season when the young caterpillars are emerg- 

 ing from the eggs. 



Natural Enemies 



The natural enemies of the cocoanut tree caterpillar may be classi- 

 fied as follows: Insect-feeding birds; lizards; insect parasites; and a 

 fungus disease. 



It is very evident that many of the young caterpillars are destroyed 

 by insect-feeding birds, both while on the ground and also while in the 

 trees before the nests have been built to form a refuge for them during 

 the daytime. They are not only eaten by the adult birds but are 

 also carried to the nests as food for the young. As neither the Eng- 

 lish sparrow or the North American robin are to be found here in any 



