Gastrophysa polygoni is a species of leaf beetle in the family Chrysomelidae, subfamily Chrysomelinae. In contemporary taxonomic references the name is treated as a junior synonym of Gastrophysa viridula (Linnaeus, 1758), the green dock beetle. Consequently, most biological and ecological information attributed to G. polygoni corresponds to that of G. viridula.
Taxonomy
- Kingdom: Animalia
- Phylum: Arthropoda
- Class: Insecta
- Order: Coleoptera
- Family: Chrysomelidae
- Subfamily: Chrysomelinae
- Genus: Gastrophysa
- Species: Gastrophysa polygoni (synonym of G. viridula)
Description
Adult beetles are small, typically 3–5 mm in length, with a rounded, convex dorsal surface. The integument exhibits a metallic hue ranging from bright green to bluish‑green, often with a slight iridescence. The elytra are smooth and lack distinct striae. Larvae are elongated, lightly sclerotised, and display a pale‑yellow to greenish coloration with a dark head capsule.
Distribution and Habitat
The species (under its accepted name G. viridula) is widespread throughout Europe, extending from the British Isles and Scandinavia to the Mediterranean basin, and reaches into parts of western Asia. It inhabits moist environments such as riverbanks, wetlands, meadow edges, and cultivated gardens where host plants occur.
Biology and Ecology
Both adult beetles and larvae are folivorous, feeding primarily on plants in the families Polygonaceae and Rumex (e.g., Polygonum spp., Rumex spp.). Feeding damage appears as irregular, skeletonized patches on leaf surfaces. The life cycle is univoltine (one generation per year) in most of its range. Adults emerge in spring, mate, and lay eggs on the undersides of host‑plant leaves. Larvae develop through several instars before pupating in the soil. Overwintering occurs as adults in leaf litter or soil debris, emerging the following spring.
Taxonomic History
The epithet polygoni stems from the Latinized reference to the plant genus Polygonum, reflecting the beetle’s association with knotweeds. Historical literature occasionally listed the beetle under this name, but modern revisions of the Chrysomelidae have consolidated it under Gastrophysa viridula. Accordingly, the name Gastrophysa polygoni is retained primarily for synonymic and nomenclatural purposes.
Conservation Status
The species is common throughout its range and is not considered threatened. It often appears in surveys of agricultural pest fauna because of its association with cultivated dock and related weeds.
References
(References are omitted per instruction; the information reflects current consensus in entomological taxonomic databases and peer‑reviewed literature.)