October, '17] DUNN: COCOANUT-TREE CATERPILLAR 487 



this lot, 10 died of fungus and 12 were destroyed by hymenopterous 

 and dipterous larvae. 



Ten were collected from within the courtyard and verandas of the 

 Laboratory. Adult butterflies emerged from 6 of this lot, 1 died of 

 fungus and 3 were destroyed by hymenopterous and dipterous larvae. 



Seven were collected from trees other than cocoanut trees. Adult 

 butterflies emerged from 3 of this lot, 2 died of fungus and 2 were killed 

 by hymenopterous and dipterous larvae. 



The total number destroyed by fungus was unusually small, but 

 being brought into a dry room and placed in separate jars may account 

 for this. 



Out of the total of 106 chrysahds, 69 emerged as adult butterflies, 

 17 died of fungus, and 20 were killed by hymenopterous and dip- 

 terous larvae. Of the 20 destroyed by the parasites, 11 were killed 

 by hymenopterous larvae, and 9 by dipterous larvae. 



Many other experiments to test the susceptibility of the chrysalids 

 to dipterous larvae were carried out. Two of these may be worthy 

 of mention. On October 5, a large gravid female fly, Sarcophaga 

 sp., was captured on the window in the room where a number of 

 caterpillars and chrysahds were confined in breeding jars. 



This fly was placed in a small jar with a caterpillar that was in the 

 prepupal stage, and was curled up and ready to cast its skin in a few 

 hours. On the morning of October 6, the caterpillar had cast its skin 

 and changed to a chrysalis. On October 7, the adult fly was dead, 

 and many young larvae could be seen crawling on the chrysalis and 

 cast skin, and many more were found feeding on the chrysalis beneath 

 the wing covers when the covers were slightly raised. On October 16, 

 nothing remained of the chrysalis but the empty case, and the larvae 

 began pupating, and by October 18, had all pupated. Nineteen adult 

 flies emerged during October 22 and 23, and 6 more emerged later on 

 October 25. The whole 25 flies had lived on this one chrysalis during 

 their entire larval period of from 9 to 11 days. 



A caterpillar was collected on October 2 and placed in a small breed- 

 ing jar, and it changed to a chrysalis on October 5. On October 6, 

 a large gravid female fly, Sarcophaga sp., was captured on a window 

 in the same room and placed in the jar with the chrysalis of less than 

 24 hours. On October 7, the fly was dead and one small fly larva 

 was noticed crawling on the chrysalis. On October 8, this larva could 

 not be seen, and no further evidence of any fly larvae was noticed 

 until October 24, when the chrysalis was examined and found to be 

 but an empty case, and upon being opened 3 dipterous pupae were 

 found inside. Two of the adult flies emerged October 28. No adult 

 emerged from the third pupa. 



