50 DRAGON FLIES VS. MOSQUITOES. 



a quarter of a mile wide and lasting from 8 A. M. until 

 it was too dark at night to see them. A close observer 

 watched a flight at Cape May this season, and adds very 

 pertinently, " The mosquitoes were as plentiful at the time 

 and afterwards." 



Southeastern Texas and east Tennessee are localities 

 where migrating Odonats are no uncommon spectacle. 



Several of the above writers have attributed this most 

 interesting habit to the fact that the ponds drying up in 

 the neighborhood caused them to abandon their haunts in 

 self defense. Such an explanation must surely fail near 

 the seaboard, where many of these swarms occurred. Be 

 the cause what it may, it will be a difficult habit to over- 

 come in case these insects are bred in ^^•holesale quantities. 



Finally, we must consider the enemies of the Odonata. 

 In the egg state we have found a small red mite, an Arach- 

 nid, which skims rapidly over the water in search of an 

 Odonat egg, upon which it either deposits an egg or exca- 

 vates it for immediate nourishment. A minute Diptron, 

 genus unknown, was also seen to oviposit on the egg of 

 Diplax. 



In laying her eggs the dragon fly has always to guard 

 against frogs, as Ave have already noted. In the larval 

 state their enemies are considerably multiplied. Belosto- 

 ma, Notonecta, and Ranatra and insects of that ilk all 

 prey upon the young larvie ; they in turn return the atten- 

 tion when they reach the latter stages. Forbes ^^ points out 

 their liability to attacks from fish. The fact that they are 

 in this stage their own worst enemy has been mentioned. 



To the perfect dragon fly, we have been unable to find 

 any constant enemy save the birds ; even they do not seem 

 to select this food with much relish. 



