SVRPIIIDAK <J]/ MA INK. 



Puparium 



Adult , ,\, 



The American vSyrphus-ily, Syrphus nm>'ncanu^ \Viedeiuaim, ;i 

 very general feeder, is one of the most valuable species in t he- 

 State 



%g i-.'i; 



Larva 



Puparium 



Adult 2y) 



Syrphus torius Osten Sacken also occurs in -real numbers among 



certain species of aphids 



Larva _> ^ , 



Puparium _>^i 



Adult 241 



Syrphus nitens Zetterstedt, a European species not heretofore 

 recorded from North America, is aphidophagous and of par- 

 ticular biological interest, because of structural peculiarities ..242 



Larva ,242 



Puparium _>4_l 



Adult 



Didea fas data Macquart var. fuscipes Loew occurs feeding among 



the Willow-grove Plant-louse j^n 



Kgg 24'* 



Larva -47 



Puparium 24$ 



Adult J4 



1 ropidia quadrata Say whose larval habits are here recorded for 



the first time, was found breeding in human excrement 24^ 



Hgg -M<) 



Larva 



Pii])arium J.si 



Adult 



The very common Syritta pipicns Linne was als<> reared from 



human excrement and from guinea-pig manure.. 



Egg 



Larva >-| 



Puparium 



Adult 



ARTIFICIAL KHVS TO THK LARVAK AXU ITI'AK ()I ; 

 SVRPH1DAK. .... 



GLOSSARY OF XKW OR I NTSIAI. T I- R.MS 



BIBLIOGRAPHY 



FIGURES. . 



