FEVER FLY. 
57 
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 Longlegs grubs in shape—that is, cylindrical 
and legless—but more prickly, and with the head brown or chestnut- 
coloured. These were plainly Tipulide grubs, 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 
Longlegs chrysalids) showed the shape of the insect forming within. 
The flies began to develop about the middle of May, and proved 
(when submitted for examination to Mr. E. H. Meade) to be the 
Dilophus vulgaris, Meigen, a small two-winged Fly (for size and shape 
see figure), of which the males are intensely black ; the females have 
the abdomen brown, and the wings brown or blackish. A second 
brood appears in autumn. 
This Fly sometimes appears in vast swarms, and in the most 
various kinds of places. It will be remembered as appearing 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 recorded as 
hanging in millions on flowers and in bunches on grasses. 
The amount of damage that it may cause is worth watching, for, 
as far as we see at present, it is one of the instances in which the 
grubs are double-feeders. They are considered to live upon the roots of 
plants, particularly of grass and corn. John Curtis, in his * Farm 
Insects,’ p. 467, notices this same species of Dilophus, then known as 
febrilis, Linn., as “ exceedingly abundant every year, and the larvae 
causing much damage in the gardens ” ; but also the grubs are to be 
found both in' horse and cow manure, and were noted by Curtis as 
found in considerable quantity in “a vine border amongst the horse 
muck” (‘ Gard. Chron.’ 1844). 
Looking at these various points together it seems very likely that 
the flies lay their eggs in the manure, and thus the grubs are intro¬ 
duced to the roots of the plants ; and if, on further investigation, the 
damage done to the roots prove important, it is this point (the presence 
of the grub in manure) which will be the one to look to first. 
