IXSECTA 249 



four species of mosquito — Aedes sollicitans Walker, A. 

 taeniorynchux Widemann, .1. cantator Toquillet and 

 Culex salinarius Coquillet, which breed only in salt 

 marshes. 



Insects are often picked up in a mass of seaweed 

 or other refuse cast up on the beach by the waves. 

 These insects can hardly be considered marine since 

 their presence in the water was probably caused by 

 an unusually venturesome flight which carried them 

 too far for a safe return to land. After a violent off- 

 shore wind the insect drift may be very large. Vari- 

 ous groups of insects are represented in this drift. 

 The common Lady Bug is among the most frequent. 



The only truly marine insects, in the strictest 

 sense of the word, are a small group of Hemiptera or 

 bugs. Whereas most of the insects mentioned above 

 spend only part of their life (either larval or adult) 

 in the ocean, these hemiptera live their entire life 

 on the surface of the sea. These wholly marine in- 

 sects belong to a single genus, Halobates, of the 

 family Gerridae. All members of this family of 

 insects live on the surface of water either fresh or 

 salt. The familiar Water Spider (Gerris) is fre- 

 quently seen on the surface of our fresh water ponds. 



Of the genus Halobates about fifteen species have 

 been described. All are inhabitants of tropic and 

 temperate seas. Some have been taken near shore 

 while others are found as much as 400 miles from the 

 nearest land. 



