q 
a 
SE ST eT ee 
THE MYCETOPHILIDA. 97. 
curious structure formed of their own excrements, and carried on 
their backs, one such structure, resembling an Ancy/us-shell. This 
has been observed by Perris in the larvae of A/ycetophila scatophora, 
and by Brauer in a species from Brazil. The larve, as a rule, spin 
a cocoon, but this is not always the case. Bolitophila, according to 
Dufour, has no cocoon; neither have certain Mycefophile. Others 
(Sciara fuscipes) have an earthy cocoon. ‘The general rule, however, 
is that some kind of case is formed for the pupz, which are found, 
as a rule, in fungi.* Some species of Sciara are also met with in 
cow-dung. Zve pupa (Fig. 15) is smooth, the angles being rounded ; 
not sharp, as in the Tipulide. (The pupze of Sciara are somewhat 
different, and strongly resemble those of the Cecidomyia.) ‘The larval 
skin is not retained in this stage, as is done in many cases. The 
legs are applied to the breast and venter; the antennz bent round 
the eyes, and their remaining portion between the legs and wings. In 
Fic. 15.—Pupa of Sczara. 
Sciara they may be expanded into a tooth at the base. In the same 
genus the prothoracic stigmata is placed on an elevation, which may 
extend into a horn. An air-tube may be seen entering it. Stigmata 
on abdomen plainly marked. 
There are certain interesting points about the larve of J/yceto- 
philide. One, is their curious habit of congregating into large bodies 
for migration; the other the brilliant luminous nature of certain 
larve in this family. The former we shall deal with when we go- 
more fully into the genus Scara, whilst now we will look at the 
remarkable phenomenon of luminosity shown by certain species in- 
cluded here. The cases of larvee emitting a brilliant light are few in 
the Diptera. This phosphorescent character has been observed in 
* Mr. Dale tells me ‘‘some larvz spin a web on the outside of a fungus, and 
turn into pupze somewhat after the manner of the small Eggar Moth (A. /anestris).”” 
This would be probably in the genus Sciophi/a. 
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