Tomasz Olbrycht¹ & Monika Kucharska-Świerszcz²

¹ University of Rzeszów, Faculty of Technology and Natural Sciences, Department of Agroecology and Forest Utilisation
² Voivodeship Inspectorate of Plant Health and Seed Inspection in Rzeszów

The juniper jewel beetle Lamprodila festiva (Linnaeus, 1767) (Fig. 1) is an invasive buprestid beetle originating from the Mediterranean region. In recent years it has been spreading rapidly across Central Europe, and since 2019 it has also been present in Poland. The larvae feed beneath the bark of plants from the cypress family (Cupressaceae) such as arborvitae/thuja, false cypress and juniper, leading to their rapid dieback [Keszthelyi & Somfalvi-Tóth 2024]. This species poses a serious threat not only to ornamental plants growing in gardens and parks, but also to native ecosystems in which common juniper occurs.

Fig. 1 – The juniper jewel beetle Lamprodila festiva

Climate change, globalised trade and dynamic urban development favour the expansion of alien/invasive species such as the juniper jewel beetle. The high availability of host plants and the specific urban microclimate mean that in built-up areas it spreads exceptionally fast [Hilszczański et al. 2025]. The species prefers warm, well-sunlit sites, which makes urban gardens and parks an ideal environment for its development.

Originally, the species occurred in the Mediterranean region. It is now recorded from many Central and Eastern European countries, including Hungary, the Czech Republic, Germany and Poland. In our country it was first observed in 2019 in Opole, with subsequent records confirmed in Poznań, Kraków and the Mazovia region [Królik et al. 2023; Szcześniak et al. 2024; Hilszczański et al. 2025]. In Rzeszów it was first noted in the spring of the current year on the grounds of the Central Laboratory of the Main Inspectorate of Plant Health and Seed Inspection (GIORiN) [PIORiN 2025]. In the second half of June—already a few weeks later—we found trees with fresh emergence holes on the campus of the University of Rzeszów in the Zalesie district. Importantly, the affected trees had been regularly monitored for the presence of this pest for several years. In our view this indicates that the species appeared in our city only very recently.

We then undertook searches for other sites within Rzeszów and recorded the beetle in the following locations:

1. Langiewicza – arborvitae (thuja) growing by the PIORiN building,
2. Langiewicza – a single arborvitae by the entrance to the military unit,
3. Zalesie district – several dozen arborvitae on: the UR campus; in the garden by the parish house; next to the OSP Zalesie fire station; and in a private garden,
4. Rejtana – several arborvitae on the grounds of the University of Rzeszów,
5. Wierzbowa – a row of more than 20 arborvitae next to the Sanitary-Epidemiological Station (Sanepid),
6. Spytka-Ligęzy – several trees and shrubs within the Complex of Schools of Economics,
7. Batalionów Chłopskich – a dozen or so trees on private property,
8. Głowackiego – several trees next to the ZUS office,
9. Sadowa – several mature trees by a residential car park,
10. Lwowska – a row of dozens of arborvitae on private property,
11. Zbyszewskiego / Lewakowskiego – a row of several arborvitae by residential blocks,
12. Króla Stanisława Augusta – a row of several arborvitae on private property (Map 1).

Map 1 – Locations where the juniper jewel beetle has been recorded in Rzeszów

Our observations show that the most important host plant of the juniper jewel beetle in Rzeszów at present is the northern white-cedar/arborvitae (Thuja occidentalis L.). The pest attacks both tree and shrub forms, from several to several dozen years old. Most of the affected plants were trees growing singly or in loose groups. A common feature of all infested plants (both trees and shrubs) was at least partial exposure of the trunk. We did not find signs of larval feeding on plants growing in dense stands with thick branches reaching the ground surface. Plants that are particularly vulnerable include those excessively pruned, with mechanical trunk damage, and those growing under poor site conditions—for example drought-stressed plants (Fig. 2).

Fig. 2 – A row of affected arborvitae on Lwowska Street

Factors promoting spread:
• climate change (milder winters, prolonged growing season);
• movement of nursery stock from countries with warmer climates;
• widespread planting of host species in urban green spaces.

Harmfulness and recognition of infestation:
• Adults feed on needles of host plants without causing major damage. Larvae feed beneath the bark, destroying the cambium and xylem, which disrupts the transport of water and assimilates and ultimately leads to plant death (Fig. 3).
• The most important symptoms indicating larval colonisation are: yellowing and dieback of whole plants or parts thereof; vertical bark cracking; resin exudation; and visible D-shaped emergence holes of adults (Figs. 4, 5, 6).
• Particularly at risk are arborvitae/thuja, junipers and false cypresses, which are popular in ornamental and municipal plantings.

Fig. 3 – Active larval galleries of the beetle beneath the bark of arborvitae

Fig. 4 – Dead arborvitae on the grounds of the University of Rzeszów on Aleja T. Rejtana

Fig. 5 – Resin exudation on the trunk of an attacked arborvitae

Fig. 6 – Emergence holes of adult juniper jewel beetles

Economic and ecological significance

1. Threat to urban greenery
Urban plantings—especially in parks, housing estates and cemeteries—often rely on plants from the cypress family. Their ease of cultivation and attractive appearance have made them dominant elements of urban greenery. Unfortunately, they are also the main hosts of the juniper jewel beetle, whose development leads to:
• mass dieback of shrubs and trees;
• high costs associated with felling and disposal of attacked plants and with replacement planting;
• deterioration of the aesthetic and natural values of public spaces (Figs. 7, 8);
• increased risk of further spread of the pest to new areas.

Fig. 7 – Dead arborvitae next to the ZUS office on Głowackiego Street

Fig. 8 – Dead and dying arborvitae on Sadowa Street

2. Threat to the natural environment
A particular concern is the potential colonisation of natural juniper (Juniperus spp.) stands [Bílý 2002]. Mass dieback could disrupt ecological balance, biodiversity and ecosystem structure.

3. Control and prevention methods
At present there are no effective chemical products approved for the control of the juniper jewel beetle. Measures to limit its spread should include:
• early detection of feeding symptoms;
• removal and disposal of infested plants before the adult flight period, which begins in May and lasts until August;
• burning, or chipping and composting of plant residues at specialist collection points;
• purchasing nursery stock only from verified suppliers;
• altering the species composition of public plantings by avoiding Cupressaceae.

The juniper jewel beetle represents a serious and growing threat to urban greenery and natural ecosystems in Poland. Its invasion is another example of the effects of global climate change and the unregulated movement of organisms associated with the trade in plants. Effective mitigation requires cooperation between public authorities, plant health services, horticulturists and residents. Further research is also needed on the species’ biology, methods of early detection and potential biological or ecological control measures.

We would like to thank our colleague Dr Mateusz Rybak from the Faculty of Biotechnology, University of Rzeszów, for his assistance in searching for new sites of the beetle.

References

1. Bílý S. 2002. Summary of the bionomy of the Buprestid beetles of Central Europe (Coleoptera: Buprestidae). Acta Entomologica Musei Nationalis Pragae, Suppl. 10: 1–104 + 16 pls.
2. Hilszczański, J., Królik, R., Ruta, R., & Szafraniec, S. (2025). Nowe stanowisko Lamprodila festiva (Linnaeus, 1767) (Coleoptera: Buprestidae) na Wyżynie Krakowsko-Wieluńskiej / A new locality of Lamprodila festiva (Linnaeus, 1767) (Coleoptera: Buprestidae) in Kraków-Wieluń Upland. Wiadomości entomologiczne (entomological news), 44, (12N): 31–32. https://doi.org/10.5281/zenodo.15429758
3. Keszthelyi S., Somfalvi-Tóth K. 2024. A story of becoming a horticultural threat, cypress jewel beetle Lamprodila festiva (Coleoptera, Buprestidae): analytical approach of its European escalation based on bibliographical sources. Ecologica Montenegrina 73: 54–71.
4. Królik R., Zawadzki M., Mazur M.A. 2023. Lamprodila (Palmar) festiva (Linnaeus, 1767) (Coleoptera: Buprestidae) – a new species in the fauna of Poland. Fragmenta Naturae, 56: 13–17.
5. PIORiN 2025. https://www.gov.pl/web/piorin/dumek-jalowcowy
6. Szcześniak S., Szpalek A., Mokrzycki T. 2024. Nowe stanowiska Lamprodila festiva (Linnaeus, 1767) (Coleoptera: Buprestidae) w Polsce z uwagami o biologii. Wiadomości Entomologiczne, 43 (online 5A): 23–27.