Blue Shieldbug – (Zicrona caerulea)

Zicrona caerulea

Family: Pentatomidae

The Blue Shieldbug is a predatory species on leaf beetle larvae in the genus Altica, a case of aggressive mimicry (when a predator resembles its prey or a harmless third party) and on moth and butterfly larvae.

Adult Size:  Length: ca. 5.0 to 7.0 mm.

Identifying features:  

A medium-small sized dark shieldbug with a dark blue/green metallic sheen and a dark wing membrane

Habitat:  Sites and habitats which support abundant populations of the larger Ieaf beetle species: including heaths, marshes, calcareous grasslands and woodland rides.

Distribution: Widespread in suitable habitats throughout Britain, especially in the north where it can be abundant.

Zicrona caerulea: Final Instar Nymph © Tristan Bantock

Months seen:

Adult: All year

Larvae: June and July. .  The abdomen of the larvae is red with black markings; these can resemble early instars of the Bronze Shieldbug but the legs of Zicrona caerulea are all dark rather than mottled and the head and pronotum are distinctly bluish.

There is usually one generation per year and new adults are mainly found from July onwards.

Distribution: It is widespread throughout Britain, particularly in the north, but absent from Ireland.

Similar species: None of the species below have been recorded in Merseyside & South Lancashire.

Thyreocoris scarabaeoides is smaller (3 to 4mm) and black with a slightly metallic blue/copper sheen, but has the scutellum covering most of the abdomen.

Canthophorus impressus is a similar size (6 to 7mm) and metallic blue-green, but with a pale edge to the corium and pronotum.

Sehirus Iuctuosus is larger (7.0 to 9.0 mm) and is less deep in side-profile and lacks the blue sheen.

North Merseysid Distribution Map

The numbers in the boxes refer to the number of records not individuals

Bantock (2018)

Bantock & Botting (2018)

Bradley (2017)

Evans  & Edmondson (2005)

Judd (2009 & 2010)

Pendleton & Pendleton (1997—2018)

Wikiwand (2018)

Wikimedia Commons (2018)