1935 ] 
Immature Stages of Macrocera anglica 
27 
Food of Macrocera 
Most Mycetophilid larvse feed on fungus spores, hence 
their old name Fungivoridse. Some species are said to be 
carnivorous. 
Norris, Wheeler and Williams attribute a carnivorous 
habit to the New Zealand “glow worm.” 
Hudson bred the larva in small tanks by feeding them 
with small flies which he regularly introduced. Thus, he 
said, “There was in fact practically nothing else in the tank 
which could have sustained the larva during the three and 
half months they have been in captivity and accounted for 
the speedy disappearance of the numerous flies so frequently 
introduced.” 
Cheetham recorded a carnivorous habit for Polylepta lep- 
togaster and Hungerford stated that Sciara coprophila fed 
on the dead bodies of the adults of their kind. 
Mansbridge and Buston showed that the droplets of fluid 
in the webs of Platyura and Ceroplatus contain oxalic acid 
of sufficient strength to kill insects coming in contact with 
it. The excretion of oxalic acid by such larvse is unexpected 
as it is by no means a product of larval metabolism. Such 
excretion is an aid to their carnivorous habit. 
I have examined by transparency several young Platyura, 
Macrocera and Ceroplatus and found their gut containing 
fungus spores. In two instances, I found the remains of 
some Collembola in the web of Macrocera, but such remains 
form a nice nidus for fungal growth. It is probable that 
these larvse may be partly carnivorous and partly fun- 
givorous. 
The larvse of Polylepta leptogaster and Sciara coprophila 
are undoubtedly fungus eaters. It is evident that the carni- 
vorous habit in Mycetophilidse should be restricted to the 
web spinning species, namely the Ceroplatinse, Macrocerinse 
and Platyurinse. 
Morphology 
The mature larva (Fig. 1, PL 4) is 20 mm. long and 1.5 
mm. broad. The dorsal surface is convex and the ventral is 
flat. The larva is more like a small annelid worm or as Du- 
four said of the larva of Ceroplatus, “Elle est larve de dip- 
