170 THE CANADIAN ENTOMOLOGIST. 



black ; the thighs are very flat and wide, inclining to ovate ; tibiae armed 

 with long black bristles. 



This I believe is the largest flea known, but I have not been able to 

 ascertain upon what animal it was captured. 



(Concluded.) 



ON TWO NEW CHALCID FLIES FROM FLORIDA, PARASITIC 

 UPON THE LARV^ OF SYRPHUS FLIES. 



BY WM. H. ASHMEAD, JACKSONVILLE, FLA. 



Having continued my investigations on Orange Insects, I have made 

 many other discoveries. Among these probably the most interesting is the 

 breeding of two species of Chalcids from the larvae of Syrphus flies. 



Now, as a general rule, the Chalcidida must be considered beneficial, 

 the majority of them preying upon other insects injurious to the agricul- 

 turist, the species belonging to the Eurytomide genus Isosoina^ being, I 

 believe, the only vegetable feeders known among them. 



In my recent pamphlet on " Orange Insects," I described and figured 

 several bred from Aphides, Coccides, etc.; besides, I have since bred 

 hundreds from other sources, and all may be considered beneficial. 



Nevertheless, there are exceptions to all rules, and those now under 

 consideration must come under that head and be classed as injurious, 

 because they prey upon the larvae of flies which destroy our orange 

 aphides — pests particularly troublesome to the orange grower in spring and 

 fall. Another strange fact about these Chalcids^ and which needs a thor- 

 ough investigation, is this : How do so many manage to live in and sub- 

 sist upon the Syrphus without destroying it at once ? For it is not until 

 the larva has transformed into a ])uparium, that these little parasites them- 

 selves transform — first into pupae, and afterwards into perfect flies, which 

 escape by eating a hole through the head of the puparium. From a single 

 puparium I had i8 Chalcids (5 males and 13 females). On carefully 

 opening another, I found it closely packed with Chalcid pupte, like " sar- 

 dines in a box." Undoubtedly all of these lived as minute worms in the 

 larva of the Syrphus fly, feeding day after day on the fatty substance, but 



