Agelastica coerulea is a small, glossy dark-blue leaf beetle that feeds on alder leaves in Korea, Japan, northeastern China, and eastern Siberia. It has not been reliably recorded in the United States. It looks very much like its close European relative, the alder leaf beetle (A. alni), and is sometimes called the East Asian alder leaf beetle.
Appearance
- Appearance
- About 1/4–3/8 in (6–9 mm) long, oval, and shiny dark blue, sometimes with a purple or green sheen. The antennae are black and threadlike.
Where it lives
- Typical habitats
- low mountain forests
- alder stands
- Range
- Korea, Japan, northeastern China, and eastern Siberia. There are no well-documented records from the United States.
Behavior
- Diet
- Adults and larvae eat the leaves of alders, scraping away the soft tissue between the veins so damaged leaves turn reddish brown.
- Overwintering
- Overwinters as an adult in leaf litter or shallow soil.
Life cycle
- Breeding season
- One generation a year. Females lay clusters of yellow eggs on the undersides of leaves in late spring.
- Larva
- The glossy black larvae feed in groups at first, then spread through the tree. Grown larvae pupate in a small chamber in the soil.
Conservation
- IUCN Red List
- NENot EvaluatedNot yet assessed
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