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bite as soon as it is sufficiently dark to prevent their being seen except in 

 profile against the skj'. The sting is verj' sharp, but it lasts only for a 

 short time as compared with that of Culex fatigans Wied., or Stegomyia 

 persistans Banks. It is ahnost impossible for these insects to fly when 

 they are filled with blood; indeed, it is with difficulty that they can lift 

 themselves from the surface upon which they are standing. 



At Los Bancs, La Laguna Province, on the evening of February 33, 

 1908, I captured two females of Mansonia uniformis Theob., one of 

 which was infested with 7 mites and the other with 1; these were cling- 

 ing to the abdomen. These mites probably belong to the family Trom- 

 biidce. As the forms were all young, it is impossible to identify them, 

 but I hope to find the adults and thus be able to place the species 

 to which they belong. As the mosquitoes were captured when it was 

 nearly dark and at random, and as two out of three captured were 

 infested, it is reasonable to suppose that this is a common parasite for 

 this mosquito. Very few mosquitoes are known to have parasites, 

 at least in the adult stage. The parasites in question measure 0.5 

 millimeter in length and are of a pale vermilion, retaining this color 

 even after two months in formalin-alcohol. The individuals, in these 

 cases, were found adhering by the proboscis to the abdominal sutures and 

 in drying remained attached to the host. 



It is my opinion that Mansonia uniformis Theob. may play an equally 

 important role in the transmission of dengue fever as does Culex fatigans 

 Wied., even if the latter be fixed upon conclusively ^* as a transmitter. 

 This mosquito has been reported from all the points in the Philippines 

 where dengue has occurred among American soldiers as an epidemic 

 during the last few years. 



"'Ashburn and Craig: This Journal, Sect. B. (1907), 2, 128. 



