1913] Determining the Flight of Mosqiiitos 9 



quitos will occur through the ravages of these animals. Collec- 

 tions of these forms must be made and the stomachs examined. 

 The best time for such collection is at or just after dusk when 

 they feed upon these dainty morsels. Unless the stomachs 

 are examined that evening, they should be preserved in 95% 

 alcohol, containing about one percent of thymol, the latter to 

 arrest enzymic action. 



Life history studies should be made at the laboratory and all 

 possible data bearing on the ecological problem collected. 



3. Historic Factors. 

 This includes the geology of the region, the plant and animal 

 association and their past history and present trend, past 

 human disturbances still exerting an influence on the biota, 

 and the past history of the mosquitos studied. 



B. DETAILED DESCRIPTION. 



Mosquitos are delicate organisms, the majority of the 

 species unable to endure intense dry heat, absence of water or 

 shelter, high winds, heavy rains, etc. They are dainty morsels 

 to hosts of alert forms. So far as our experiments are concerned, 

 additional factors enter to lessen the number of released adults 

 which may be recovered. First, the female almost exclusively 

 is able to suck blood. Second, mosquitos are not dependant 

 upon human blood alone. We have noted mosquitos sucking 

 the blood of horses, mules, dogs, cats, monkeys and fowls. 

 The need, then, for releasing large numbers of colored adults 

 is evident. Better results will follow if thousands of mosquitos 

 are liberated. 



1. Collection and Care of Larvce and Pupce. 



A. Collection: Mature or nearly mature larvae and all 

 pupae, of the species selected for study, should be collected. 

 Young larvae thrive poorly in the field laboratory. All preda- 

 cious larvae must be excluded from the receptacles containing 

 larvae and pupae. 



A white enameled or porcelain saucer is very satisfactory in 

 "dishing-up" water and algas to note whether mosquito larvae 

 are present. The larvae, if there, stand out in bold relief 

 against the white back-ground. If the larvae and pupae are 

 abundant, a large white enameled dressing bucket (such as is 

 used by hospitals) should be used to dip up quantities of the 



