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152 JOURNAL OF ENTOMOLOGY AND ZOOLOGY 



male retired to a support although the species was never observed 

 to swarm during the hours of sunlight. 



The number of individuals participating in these swarms was 

 again very astonishing, many of the swarms numbering thousands 

 of individuals. The motions in the swarms were very rapid, almost 

 like bees, and the sound produced was a very low pitch, much lower 

 than that of Ciilex. 



May 29, 1914 — A rather strong southerly breeze blowing. At 

 6:35 p. m. small swarms of from 25 to 30 individuals had gathered. 

 At this time the sun was still up but low in the west. These swarms 

 were enlarged rapidly. At 6:45 one big swarm was formed near 

 the east bank, this being nearest the point where the insects spend 

 their days and so they swarmed there first. One pairing of three 

 individuals came down as described above and when about a foot 

 above a board in the water, the male in copulation dropped the other 

 two. These rested for a moment and then the male attempted to 

 engage the female in copulation. She resisted but finally he man- 

 ageci to seize her with his forceps. Then he attempted to fly away 

 but she seized hold of the board with all her feet and he was un- 

 able to fly away. This seems to prove that the normal place for 

 copulation Is in the air. 



Enemies: Dragon-flies, HclocorduVui ulileri Selys, feed upon the 

 Eriocera swarms during sunlight. They do their capturing by dart- 

 ing back and forth through the masses of individuals. 



Oviposition: Many Eriocera were noted engaged in dipping 

 down to the water as though engaged in the laying of eggs. Only 

 a few individuals allowed themselves to be taken and all of those 

 secured proved to be males. Why males should go through these 

 actions is uncertain to me, but I have observed it many times In 

 several different species. I think that the female lays her eggs In 

 the water although no specimens were taken while egg-laying. 



PENTHOPTERA Schlner 



This interesting genus includes but six described species of which 

 P. chirothecatd Scop., P. cimicoides Scop., P. schuiisei Kuntze and 

 P. grisea RIedel are Palaearctic, P. alhitarsis O. S. Is Nearctic and 



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