Description of the insect
- The adult (figure 1) of Byctiscus betulae measures between 4 and 7 mm in length. It has a stocky appearance and is variable in color (coppery green, coppery purple or blue). It has a broad elytron (hardened and horny fore wings), a short rostrum and straight antennae.
- The eggs (figure 2) are light white, opaque, then they tend to turn yellow. They have an ovoid shape and measure 0.5 mm.
- The larvae white are legless and soft. They have a brown to black chitinous head and measure at the end of their development between 5 and 6 mm long.