714 



Charles Paul Alexander 



The specialized methods of oviposition in the Cylindrotominae have 

 already been discussed on page 709 under the account of Cylindroioma 

 splendens. The species of Tipula and other genera the females of which 

 have blunt valves to the ovipositor (Styringomyia, Macromastix, and 

 others), all probably scatter their eggs promiscuously or else have a special- 

 ized method of egg-laying. Similarly, the species of Tipula of the arctica 

 group, in which the dorsal valves of the ovipositor are very large, placed 

 horizontally, and with the margin finely serrated, undoubtedly have a 

 peculiar method of oviposition, but this has not yet been observed. 



The egg 

 The number of eggs laid by crane-flies varies from about forty-five in 

 Styringomyia to some two thousand in the larger species of Eriocera. 

 The following table indicates the general range in the group: 



Species 



Ptychoptera albimana . 

 Styringomyia didyma . 

 Eriocera longicornis . . 



spinosa 



Hexntoma megacera . . . 

 Phalacrocera replicata . 



Liogma glabrata 



Ctenophora angustipennis . 

 Tipula cunctans 



bicornis 



tephrocephala .... 



angustipennis .... 



collaris 



dejecta 



oleracea 



Number of eggs laid 



Maximum Minimum Average 



587 



45 



1,034 



2,061 



372 



60 



60 

 400 



297 

 255 



eo2 



329 

 366 

 600 



520 



872 



1,824 



316 



200 



282 



251 



554 

 45 



952 

 1,942 



347 

 60 



60 

 300 

 300 

 289 

 255 

 602 

 329 

 309 

 600 



Reference 



Topsent, 1914-16 

 Terry ms. 

 Alexander ms. 

 Alexander ms. 

 Alexander, 1915 c 

 Miall and Shelford, 



1897 

 Miiggenberg, 1901 

 Lovett, 1915 

 Hvslop, 1910 

 Webster, 1893 b 

 Webster, 1893 b 

 Hyslop, 1910 

 Alexander ms. 

 Alexander ms. 

 Del Guercio, 1914 



The eggs are in most cases elongate with the ends narrowed and rounded, 

 or, in other words, spindle-shaped. The chorion in the species of Tipula, 

 Hexatoma, and other genera is blackened and in some cases more or less 

 sculptured. In Ctenophora angustipennis (Lovett, 1915) the egg is ebony 

 black with deep purple reflection, elongate-oval, uniform, without pits or 

 ridges, and measuring from 1.26 to 1.4 millimeters by 0.375 millimeter. 



