These insects are often found in large numbers on plants whose juices they suck.
The cut cells die, and oxidized products are concerned in the change of color, the brown juices exuding and soaking into the cell-walls.
The phenomenon is, in fact, very like that of the fermentation of palm wine and pulque, where the juices are obtained from artificial cuts.
Comparable with these cases is that of Cuckoo-spit, due to the juices sucked out by Aphrop/ttkora~ on herbaceous plants of all kinds.
2 b) possess slender, curved, hollow mandibles, which are perforated at the tip and at the base, being thus adapted for sucking the juices of victims. Large dyticid larvae often attack small fishes and tadpoles.