482 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 10 



The female butterflies can readily be distinguished from the males 

 as soon as they emerge from the chrysalis case, because the large num- 

 ber of eggs contained by the female greatly distends the abdomen. 

 The chrysalids, near the time for emergence, offer some evidence of 

 sex differentiation since the females are larger than the males. 



Few of the adults are to be seen in flight excepting at night or late 

 evening, and are then sometimes seen in numbers. The few that are 

 to be noticed in the daytime are generally females and are supposedly 

 seeking a place to deposit their eggs. It has been impossible to obtain 

 any data on the feeding habits of the adults. 



There appears to be a variation in numbers between the spring and 

 fall broods. In some seasons the spring broods are the greatest in 

 numbers and do the most damage and the fall brood may be very 

 small, and the following year it may be the opposite and the greatest 

 damage may be caused by the fall brood. This difference may prob- 

 ably be caused by the methods of control applied and also be in- 

 fluenced by the action of parasitic enemies. 



The fall broods seem to have a slightly longer caterpillar period, 

 but as they are in this stage during the dry season of the year in 

 Panama, it may be that this tends to lengthen the period. 



Preventive Measures 



Methods of control such as spraying, etc., that ordinarily proves 

 effective with leaf eating insects in the Temperate zones are almost 

 impossible in this case. While these caterpillars are leaf-eating and 

 should be susceptible to stomach poisons, their environs render the 

 application of such poisons as expensive and useless procedure. 



The spraying of cocoanut trees is impractical in Panama especially 

 during the rainy season, and the height of full-grown trees causes 

 spraying to be tiresome and extremely difficult at any season. It is 

 either necessary to use long extension pipes with a nozzle on the end 

 and these are generally so unwieldy that it is difficult to direct the 

 spray. Long ladders might be used with a man at the top of the ladder 

 with a short spray pipe connected with a rubber hose to the pump. 

 This is also an unhandy manner of working as the man is then directly 

 under the foliage to be sprayed. In either case a very strong pressure 

 is required to give necessary force to the solution at such a height. 

 Even if a spray could be applied by some easier method the sudden 

 and heavy rains so common in this region would be liable to wash it 

 off almost as soon as applied. 



Owing to the nesting habits of these caterpillars and to their remain- 

 ing hidden within the nests during the daytime, if a little care is ex- 

 ercised they may be kept under complete control by the removal of 

 the nests with the caterpillars inside. 



