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Tritomegas bicolor Pied Shieldbug
Family: Cydnidae

A distinctively marked black and white shieldbug which is  unmistakeable as an adult. Like other members of this family, it is a ground-dwelling species, but may be found feeding on the aerial parts of white dead-nettle and black horehound, the main hostplants. The sexes can vary considerably in size.

Widespread in southern Britain in hedgerow and woodland edge habitats, becoming rarer northwards and absent from Scotland and Ireland.

There may be two overlapping generations each summer and females exhibit brood care of the eggs. While later larval stages are characterstic, early instar nymphs lack the pale patch on the pronotum and may be confused with those of Eysarcoris venustissimus.

Adult: All year
Length 5.5-7.5 mm

see illustrated life stages chart

Tritomegas bicolor
Adult: Berks (April 2009) ©Jonathan Michaelson

Tritomegas bicolor Tritomegas bicolor
Adults: north London (April 2009) ©Tristan Bantock

Adult: Lincs (April 2007) ©Rachel Scopes

Tritomegas bicolor nymph Tritomegas bicolor nymph
Nymph: Berks (June 2008) ©Jonathan Michaelson

Nymphs: Surrey (July 2008) ©Ashley Wood
Tritomegas bicolor nymph
Nymph: Notts (July 2007) ©Trevor & Dilys Pendelton (Eakring Wildlife)