Shield-backed bugs

Definition

Common name for true bugs of the family Scutelleridae (Heteroptera), referring to the diagnostic enlargement of the scutellum into a continuous, often metallic shield that completely covers the abdomen and folded wings. This morphology distinguishes them from most other heteropteran families and can cause superficial resemblance to beetles (Coleoptera). The group includes approximately 450 species worldwide, many with brilliant metallic coloration (hence also 'jewel bugs'), and shares with related pentatomoids the capacity to emit defensive secretions.

Etymology

From the enlarged thoracic scutellum forming a dorsal shield covering the abdomen and wings; 'shield-backed' distinguishes their silhouette from typical shield bugs (Pentatomidae) where the scutellum is smaller and triangular.

Example

The Indian jewel bug Scutellera nobilis and the green stink bug relative Chrysocoris stolli are familiar shield-backed bugs whose enlarged scutellum completely conceals the hemelytra, unlike the triangular scutellum of true stink bugs (Pentatomidae) that leaves the corium and membrane partially exposed.

Synonyms

• jewel bugs
• metallic shield bugs
• Scutelleridae

Related Terms

• scutellum
• Heteroptera
• Pentatomidae
• Hemelytra
• true bugs
• jewel beetles

Usage Notes

The term specifically denotes family Scutelleridae, not merely any bug with a shield-like appearance. Contrast with 'shield bugs' (Pentatomidae), where the scutellum is smaller and does not cover the wings. The complete wing coverage by the scutellum is the key diagnostic character separating Scutelleridae from most other Heteroptera. Some authors reserve 'jewel bug' for brightly colored species and use 'shield-backed bug' as the broader common name for the family.