March, 1907.] KnAB : COPULATION OF StEGOMYIA CaLOPUS. 17 



observations, by the writer and others, show that there are two distinct 

 modes of copulation in this family, each correlated with a difference 

 in claw structure in the female. The mode described above obtains 

 in the species in which the claws of the female (first and second, or 

 all three pairs of feet) are toothed. It has been observed in Stegomyia 

 calopiis by Goeldi and the writer, and in Acdes varipalptis by Dr. H. 

 G. Dyar. These, together with the record of Godeheu de Riville, are 

 the only authentic observations known to the writer of this mode of 

 copulation. The other mode appears to be common to all the species 

 in which the female has simple claws. In the case of these copulation 

 likewise takes place in the air but differs strikingly in the relative 

 position of the two sexes. When the two sexes meet in the air they 

 grapple for a moment until union is effected, then, releasing their hold 

 of each other, continue flight united but facing in opposite directions. 

 The heavier female drags the male after her, the longitudinal axes of 

 their bodies forming a straight line. The writer has observed copula- 

 tion in this manner in Anopheles punctipennis and Culex pipiens, and 

 Dr. Dyar in Culiseta consobrinus."-^ 



With the above data on the mating habits of mosquitoes we can 

 now approach the question of the identity of the species observed by 

 Godeheu de Riville. From the description it is very clear that the spe- 

 cies was one in which the claws of the female are toothed. Moreover 

 there are but very few species of mosquitoes that are sufficiently do- 

 mesticated to breed on board ship. Of all the species with toothed 

 claws Stegomyia calopus is the only one that has to any degree associ- 

 ated itself with man, and indeed, as is well known, has been dissem- 

 inated by shipping throughout the warmer regions of the earth. An- 

 other factor that points conclusively to Stegomyia calopus is the fact, 

 brought out in Godeheu de Riville's account, that the mosquitoes 

 were most active during the warmest hours of the day, a characteristic 

 habit of this species. There is no other species that comforms with 



* Contradictory of these observations, Dr. A. Eysell credits both Anopheles and 

 Ctitex with the mode of copulation first described (Archiv f. Schiffs-u. Tropen 

 Hyg-> ^- 9» P- S^y I9°5)- I"^ '^6 ^^^^ °f Anopheles his statement is credited to the 

 observation of Schaudinn, but I have so far been unable to find the original record. 

 For Culex his basis is a note by Grassi on Culiseta spathipalpis (Studi di uno zoologo 

 sulla malaria, p. 84, 1900). Dr. Eysell's assertion is evidently based on a misinter- 

 pretation, for a careful study of the original text reveals nothing that indicates the re- 

 lative position of the two sexes. 



