vii SYRPHIDAE HOVER-FLIES 499 



able resemblance to Hymenoptera of various groups. The 

 peculiar reining of the wings permits of their easy identification, 

 the line of two nervules, approximately parallel with the margin 

 of the distal part of the wing (Fig. 212, D), and followed by a deep 

 bay, being eminently characteristic, though there are some excep- 

 tions ; there are a few forms in which the antennae are exceptional 

 in having a terminal pointed process. The proboscis, besides 

 the membranous and fleshy lips, consists of a series of pointed 

 slender lancets, the use of which it is difficult to comprehend, as 

 the Insects are not known to pierce either animals or vegetables, 

 their food being chiefly pollen ; honey is also doubtless taken 

 by some species, but the lancet -like organs appear equally 

 ill -adapted for dealing with it. The larvae are singularly 

 diversified ; first, there are the eaters of Aphidae, or green-fly ; 

 some of these may be generally found on our rose-bushes or on 

 thistles, when they are much covered with Aphids ; they are soft, 

 maggot -like creatures with a great capacity for changing their 

 shape and with much power of movement, especially of the 

 anterior part of the body, which is stretched out and moved 

 about to obtain and spear their prey : some of them are very 

 transparent, so that the movements of the internal organs and 

 their vivid colours can readily be seen : like so many other 

 carnivorous Insects, their voracity appears to be insatiable. The 

 larvae of many of the ordinary Hover-flies are of this kind. 

 Eristcdis and its allies are totally different, they live in water 

 saturated with filth, or with decaying vegetable matter (the 

 writer has found many hundreds of the larvae of Myiatropa 

 florea in a pool of water standing in a hollow beech-tree). These 

 rat-tailed maggots are of great interest, but as they have been 

 described in almost every work on entomology, and as Professor 

 Miall l has recently given an excellent account of their pecu- 

 liarities, \ve need not now discuss them. Some of the flies of 

 the genus Eristcdis are very like honey-bees, and appear in old 

 times to have been confounded with them ; indeed, Osten Sacken 

 thinks this resemblance gave rise to the " Bugonia myth," a 

 fable of very ancient origin to the effect that Honey-bees could 

 be procured from filth, or even putrefying carcases, by the aid of 

 certain proceedings that savoured slightly of witchcraft, and 

 may therefore have increased the belief of the operator in the 



1 Xatural History of Aquatic Insects, 1895, p. 198. 



