THE ANIMAL FILES

Cockchafer

Melolontha melolontha

A few spring weeks above ground follow years below it.

Adult cockchafers have fan-like antennae and feed on tree leaves. Before this brief above-ground stage, they spend several years as root-feeding grubs, then pupate and overwinter as adults in the soil.[1]

Follow the evidence ↓
Cockchafer
Image: Frank Vassen from Brussels, Belgium · Commons · CC BY 2.0
Adult antennae
Fan-like leaf-shaped extensions[1]
Larval feeding
Plant roots below ground[1]
Adult feeding
Leaves of several kinds of trees[1]

A fan at the front of the beetle

Adult cockchafers have reddish-brown wing covers and large fan-like antennae. Males have seven leaf-like extensions and females six, with the male fan generally larger.[1]

The hidden years belong to a grub

The pale, curved larva has a brown head, strong jaws and developed legs. It forages below ground for roots and passes through several larval stages over years.[1]

Different stages use different food

Adults feed on leaves and emerge in spring, while females return to soil to lay eggs. Later, larvae feed underground rather than joining adults on branches. Metamorphosis changes both body form and where food is collected, connecting a tree canopy with the soil and roots beneath it.[1]

A COMMON MIX-UP

Is the spring beetle only a few weeks old?

Not necessarily. The adult stage is relatively brief, but it follows a larval period lasting several years. Adult age and total age are different measurements when an insect undergoes a long juvenile stage.[1]

TRY A LITTLE REASONING

Why might a leaf survey miss most of the life cycle?

Reveal the explanation

Leaves reveal adult feeding, but larvae develop and feed in the soil. To connect the visible beetle with its development, observations must include both the above-ground adults and the hidden root-associated stages.[1]

Sources & editorial notes

Adapted and translated from the cited Wikipedia revisions, with source-linked reasoning. Image credit and licence are listed separately above.

Adapted and translated from Wikipedia contributors; exact revisions are linked below. CC BY-SA 4.0

  1. Wikipedia contributors — Cockchafer (fixed revision; adapted and translated)
  2. NCBI Taxonomy — Melolontha melolontha (identity and classification)

Last fact check:

One discovery leads to another

Sacred scarabA rolled dung ball can become both a meal and a nursery.Scarabaeus sacer ↗Hercules beetleThe horns lift rivals; the larvae spend their time in rotting wood.Dynastes hercules ↗European stag beetleThe “antlers” are jaws, and the long childhood is spent in decaying wood.Lucanus cervus ↗