Hawthorn shield bug (Acanthosoma haemorrhoidale)
Hawthorn shield bug (Acanthosoma haemorrhoidale)
Hawthorn Shieldbug – Biology & Identification
Discover Acanthosoma haemorrhoidale: appearance, life cycle, diet, and tips on how to spot and protect the hawthorn shieldbug in your garden.
Key Facts
- Size: 15–17 mm
- Coloration: Apple green in spring, yellow-green to brownish in late summer
- Diet: Plant sap from hawthorn, rowan, and related species
- Active: April–October, overwintering as adults in leaf litter
- Distribution: Across Europe in woodlands and hedgerows
- Scientific name: Acanthosoma haemorrhoidale
- Common name (German): Wipfel-Stachelwanze (hawthorn shieldbug)
- Family: Acanthosomatidae
- Egg-laying: May–July on leaf undersides
- Generations: One per year
Table of Contents
- Introduction
- Appearance
- Typical Features
- Diet
- Reproduction & Life Cycle
- Seasonal Behavior
- Habitat & Distribution
- FAQ
- Conclusion
Introduction
The hawthorn shieldbug is one of the most striking native shieldbugs. With its bright apple-green coloration in spring and its shift to warm yellow and brown tones in late summer, it blends perfectly into the surrounding vegetation. It prefers hawthorn and rowan hedges, where it feeds on plant sap and reproduces. This guide provides everything you need to know about its appearance, life cycle, and role in the garden.
Appearance
At 15–17 mm long, Acanthosoma haemorrhoidale is relatively large. It looks broad and flat, with a finely punctuated body surface.
- Spring: bright apple green, blending into fresh foliage.
- Summer/Autumn: turning yellow-green or brownish.
- Markings: two reddish-brown stripes form triangles on the pronotum and forewings.
- Head: yellow-black longitudinal stripes.
- Scutellum: triangular with a fine row of punctures.
Typical Features
- Abdominal keel: pointed projection on the underside – typical of shieldbugs.
- Seasonal color change: green in spring, shifting to yellow or reddish tones in autumn.
- Punctures: evenly distributed on pronotum and forewings.
- Legs: slender with two-segmented tarsi, well adapted for climbing.
Diet
The hawthorn shieldbug uses its long piercing-sucking mouthparts to feed on plant sap:
- Main host: hawthorn (Crataegus)
- Other host plants: rowan, wild cherry, beech, oak
- Late summer: also feeds on berry juices for sugar intake
Reproduction & Life Cycle
- Egg-laying (May–July): yellowish eggs in clusters on the undersides of leaves.
- Nymphal stage (June–August): several molts; nymphs live in leaf litter, feeding on decaying leaves and small insects.
- Pupal stage: development in the litter layer, lasting several weeks.
- Adults: emerge in late summer, with only one generation per year.
Seasonal Behavior
- April/May: overwintered adults emerge and mate.
- Summer: feeding and egg-laying; gradual color change.
- Late summer: basking on branches, preparing for overwintering.
- Autumn/Winter: adults overwinter under leaf litter or bark.
Habitat & Distribution
This species is widespread across Europe, though rarer in the far north. Preferred habitats include:
- Deciduous forests
- Hedgerows with hawthorn or rowan
- Gardens, provided host plants are present
FAQ
1. How can I distinguish the hawthorn shieldbug from similar species?
By its abdominal keel, reddish-brown triangular markings, and its size of up to 17 mm.
2. Is it harmful to fruit trees?
No, in small populations it causes little to no damage.
3. When can I find eggs and nymphs?
Eggs from May to July on leaf undersides; nymphs in June and July in leaf litter.
4. Can I help conserve the species?
Yes – plant native shrubs, maintain natural hedges, and leave leaf litter.
5. What are its predators?
Parasitic wasps, spiders, and other insect hunters.
Conclusion
The hawthorn shieldbug is a fascinating resident of our forests and gardens. Its seasonal color changes make it an attractive insect to observe. By planting hawthorn and leaving leaf litter, you can help provide habitats for this native species and enjoy its presence in your garden.
