4 DRAGON FLIES VS. MOSQUITOES. 



Possibilities and Cost. — Insecticide substances — ]Many too 

 expensive to be of practical value — The use of fungoids 

 a ])romising one — Research by Pasteur — Diseases of the 

 silk worm — Fly fungus — Yeast fermentation — ]Mould — Mul- 

 tiplication of electric lights — Chemical and animal ene- 

 mies — Sunfish— Drainage — Night hawks — AVliippoorwills— 

 Bats — Lantern traps — Culture of dragon flies— Methods- 

 Experiments with oil — Cost — General insecticides — Final 

 summing up 57-68 



UTILITY OF DRAGON FLIES AS DESTROYERS OF 



MOSQUITOES. 



By Archibald C. Weeks. 



Natural Conditions i-xder which Dragon Flies Breed. — 

 Valuable and interesting table of time, appearance, locality, 

 flight, voracity, strength of wing, etc., of dragon flies — De- 

 scription of ovii>osition— Duration of larval stages — Two 

 broods of infrequent occurrence 73-75 



Experiments in Rearing, Imitating Natural Conditions.— 

 Success with aquatic Neuroptera — Cages for raising various 

 species— Caddis fly— Diptera— Upper portion of house util- 

 ized as a temporary nursery for dragon flies — Bath tub 

 disguised with sand, rushes, and aquatic grasses . . . • 75 SO 



Habits of Dragon Flies limited to scope of Object to be 

 Accomplished.— Distinctively diurnal — Totally inactive at 

 night — Light and heat required— Ample space and great 

 freedom — Butterflies as food 80-81 



Natural Conditions under which House Flies Breed. — Va- 

 rious species — Parasitic varieties — Habitat— Annoyance to 

 man and beast— Habits— Experiments in rearing . . . 81-84 



Natural Conditions under which INIosquitoes Breed. — Flies 

 AND Mosquitoes.— Habits in general— Flies as scavengers 

 of earth and air— Natm-e's faithful servants— Relations to 

 each other— Conclusive testimony— Dragon flies incapal)le 

 of domestication— Objectionable inhabitants of our homes — 

 Difficulties of breeding— Centipedes— Methods of abating 

 the mosquito and fly nuisance — Interrupt the chain of 

 conditions which is most favorable to their development — 

 Drainage— Grading — Removal of organic debris — Accumu- 

 lation of filth in the streets should not be permitted— 

 Cellars and yards should be visited by a sanitary inspec- 

 tor — No slaughter house should be maintained within city 



