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The most destructive insect enemy of Cocos nucifera in Panama is 

 the butterfly, Brassolis isihmia, which is native to the country. 



Injury is confined to the larval stage, when the caterpillars begin 

 to feed midway down the leaflets, frequently eating through the mid- 

 rib and amputating the distal end, which falls to the ground. The 

 caterpillars fasten the ends of the leaflets together from opposite 

 sides of the main stalk so that they extend downwards, thus forming 

 a nest in the shape of a funnel-like bag which is lined with silk and 

 frequently divided into several compartments. The leaflets are 

 probably brought down into position by the weight of the large numbers 

 present in the nests, ranging from 50 to 2,000. Injury has been known 

 to extend to other trees, caterpillars ha\dng been observed in numbers 

 feeding upon the royal palm, though no nests have been found in 

 these trees. 



There are two broods of B. isthmia in a year. The first eggs are 

 deposited in May and June, and those of the second generation from 

 late October until early December. The different stages largely 

 overlap and all forms may be found at one time. Eggs are frequently 

 laid on the lower sides of leaves or on the trunlc of the coconut, but 

 many are also found on buildings or in any sheltered place, protection 

 from the weather evidently being the chief purpose in the choice of 

 a site. They are laid in masses ranging from 150 to 300, and are 

 covered with a clear mucilaginous substance and hatch in 25 to 30 

 days. Nest-building is accomplished before the larvae reach maturity. 

 These nests, when well constructed, are generally waterproof and afford 

 good protection from enemies, and as the larvae are nocturnal in habit 

 and seldom appear by day, they are very difficult to deal with and may 

 destroy all the fofiage on a tree in a few nights. During April, and 

 again in September, the mature larvae of the two generations leave 

 the trees and seek places in which to pupate. The pupal stage 

 lasts from 14 to 17 days. 



Methods of control such as spraying are unsatisfactory owing to the 

 habits of the caterpillars, while the application of stomach poisons 

 would be expensive and almost useless under such conditions. The 

 only effectual remedy is the removal of nests with the caterpillars 

 inside ; these can then be crushed in heavy mortars or thrown on 

 a hot fire, or may be killed by dipping in a strong contact insecticide. 

 This is a troublesome method, the nests being lugh in the trees and 

 requiring long extension ladders to reach them, but if done at the 

 proper time, once during the season should be sufficient. They should 

 be removed early and before the caterpillars have become fully grown, 

 otherwise these ^vill have left the nest to pu^mte before it is removed. 

 Banding the trees with a thick coat of tar or other sticky substance 

 at some distance from the ground \d\\ prevent young ' caterpillars 

 from reaching the leaves, if carried out at the tinie when the young 

 larvae are hatching. 



Natural enemies of B. isthmia include birds, toads, lizards and ants. 

 Parasitic msects destroy many pupae, but experiment has proved 

 that It is the pupal stage only that is attacked, after the caterpillars 

 have done the damage. These parasites include Chalcids, Sarcophagids 

 and Tachimds, but unfortunately they are not peculiar to B. isthmia, 

 merely attacking it as an accidental or occasional host. More impor- 

 tant than any parasitic enemy is a fungus that attacks the mature 



