FEVER FLY. 129 



Fever Fly." Diln/ilius ruli/aris, Meigen ; T). fehrilis, Linn. 



Dilophtis rulgarit! : Female Fly magnitied and nat. size, flying round Hop-cones. 



This Fly sometimes appears in vast swarms, and in the 

 most various kinds of places. It appeared amongst the Hop- 

 cones at Eainham, in Kent, in 1882 ; it has been observed in 

 enormous numbers off the Norfolk coast : in 1862 it was re- 

 corded as hanging in millions on flowers and in bunches on 

 grasses. 



At the beginning of April, in 1884, specimens of larvae 

 were forwarded to me from near Sittingbourne, with the in- 

 formation that they were found in a piece of Hop -root sent 

 accompanying, and appeared to be feeding on it, and that the 

 same kind of grubs were then rather numerous in the Hop- 

 hills. The piece of Hop was partly decayed, and, on cleaning 

 it to gain a sight of the state of surface, it appeared freshly 

 injured, as if the grubs were feeding on it, — that is, on the 

 live part, not merely on the decayed matter outside. 



A few days later it was reported from Sharsted that, 

 " These grubs appear to be doing much damage to the Hop- 

 plants by gnawing away the original plant, and considerable 

 quantities of them may be found even at one stem." 



These little grubs were only about a quarter of an inch in 

 length and like small Daddy Longiegs grubs in shape — that 

 is, cylindrical and legless — but more prickly, and with the 

 head brown or chestnut-coloured; and about three weeks later 

 a further supply was sent, of which some were then gone on 

 to the chrysalis stage — whitish, and which (like the Tipulide 

 or Daddy Longiegs chrysalids) showed the shape of the 

 insect forming within. 



The flies began to develop about the middle of May, and 



* As this Fly appears to be without an English name, I have retained the 

 original one given by Linna)us from the Fly being supposed to occur in the 

 rooms of fever patients. 



K 



