Figure 1. The mandible morphology of Z. filipendulae enables leaf-snipping to ingest and digest large leaf fragments.

A. Larva of Z. filipendulae feeding on its host plant L. corniculatus, which contains the cyanogenic glucosides linamarin and lotaustralin. The mouthparts including the mandibles are indicated by an arrowhead. The larva is ∼ 2.5 cm long. B. Frontal-ventral view of the head with the two mandibles laying partly over each other. The distance between the bases of both mandibles is ∼ 600 µm (arrowheads). The leaf-processing area of the mandible is indicated by a dashed line. Both mandibles are partly covered by the labrum in a closed position. C. The right mandible viewed dorsally showing a round, concave and non-toothed shape with a length of ∼ 400 µm and a width of ∼ 300 µm. The leaf-processing area is indicated by a dashed line. D. The larval gut content shows that ingested L. corniculatus leaf fragments are relatively large and match the dimensions and morphology of the two mandibles. E. Detail of a representative L. corniculatus leaf fragment from the larval gut which is ∼ 550×450 µm - a similar size is retained in the frass (F.).