THE NARCISSUS- OR DAFFODIL-FLY. 



183 



July 12, when all my bulbs were dug up ; but on examining the bulbs 

 carefully I have since found Merodon grubs of all ages, some minute little 

 white specks, others full-grown, and all sizes between ; I am entirely at 

 a loss to understand the very great difference in size and presumably in 

 age of the grubs found in the harvested bulbs in the end of July. The 

 full-grown grub is white or cream colour (turning dingy black when at 

 rest), with a very round black noticeable hard spot for a head. It is aboul 

 three-quarters of an inch long and exceedingly fat, like a miniature roly- 

 poly pudding. In fig. 60 the fly is an exact and lifelike representation, 



[ 



Fig. 60. — Merodon equestris — Fly and Grub. (Gardening Illustrated.) 



but the grub is not so oval-shaped nor the chrysalis so pointed as 

 represented ; they are both much more flat-ended. 



From my own observation I am convinced that in the majority of 

 cases, if not in all, the grubs work their way down through the neck of 

 the bulb and eat their way straight down the very centre of the heart of 

 the* bulb to the base where they seem generally to make a small hole 

 through, possibly to act as a cloaca, and then they turn upwards to finish 

 their course, emerging again by the same road they entered. I have 

 found young grubs embedded in the centre of the bulb-neck, and on 

 cutting open the bulbs they have been as yet perfectly sound and 

 uninjured below. I am therefore strongly of opinion that Mr. Williams 

 is mistaken in thinking the grub generally enters the bulb from below. 



