248 THE MOSQUITOES OF NEW JERSEY 



results seem to support our statement, at least as far as algae are con- 

 cerned, that food supply is determined by the chemical composition of 

 the water. Since it seems fairly clear that mosquito larvae will eat what 

 they can get and the choice of breeding place might depend on the type 

 of food present, we must know from the chemist and specialized biolo- 

 gist which chemical factor or factors determine sufficient food supply, 

 why it is that sometimes only a certain type of growth occurs, or what 

 causes partial sterility of the water. After we know something about 

 these things, a modification of factors governing food supply might 

 then be comparatively easy and the road is open for a different type 

 of mosquito control." 



NATURAL ENEMIES 



Birds, bats, and dragon flies eat adult mosquitoes. Dragon fly 

 nymphs and predaceous diving beetle larvae feed on the wrigglers, cer- 

 tain tadpoles and salamanders destroy mosquito larvae. Certain "hair 

 snakes" and mites are known to parasitize mosquitoes. 



All these enemies, however, are of small importance in comparison 

 with the killifish which live in creeks, ditches, and pools of salt marshes 

 and are the great natural enemies of salt marsh mosquito larvae. No 

 adult mosquitoes emerge from waters containing them. 



The following list covers some of the recognized natural enemies of 

 mosquitoes : 



INVERTEBRATES 



Protozoa — Spirochaeta culicis, Diplocystis, Nosema stegomyiae,. 

 Crithidia fascicidata, Herpetomonous algeriense, Trypanosoma cidicis^ 



Coelenterata — Hydra fusca, Hydra viridis. 



Platyhelminthes — AgamodistomuTii martiranoi. 



Nemathelminthes — AgaTnomermis culicis. 



Arthropoda — Hydrophilus obtusatus, Dytiscus marginalis, Acilus 

 sidcatus, Nepa, Notonecta, Ranatra fusca, Aeschna, Erythemis simpli- 

 cicollis, Psorophora ciliata, Megarhinus septentrionalis, Lutzia bigotii, 

 Lesticocampa, Corethra, Tanypus dyari, Lispa sinensis, Horpopeza 

 obliterate, Tahydromia macida, Cordilura haemorhoidalis, Monedula 

 signata, Emesa longipes, Salticus, Crangon vulgaris. 



VERTEBRATES 



Pisces — Ftindidus heteroclitus, F. majalis, F. diaphanus, Gambusia 

 afjinis, Cyprinodon variegatus, C. calaritanus, Heterandria, Ambramis 

 chrysolencas, Carassius atiratus, Eupomotis gibbosus, M ollienisia- 



