A Mediterranean mantis quietly colonises Hungary, and citizen scientists caught it happening

Deep in the heart of Central Europe, a tiny Mediterranean predator is quietly rewriting the map of European insects. Ameles spallanzania, a dwarf praying mantis barely longer than a paperclip, has been caught establishing breeding populations in Hungary — a country where it had never been recorded until a single specimen turned up in the back of a car in 2020. Now, a new study published in the journal Evolutionary Systematics documents 27 localities across the country, revealing that this warm-loving mantid is not just passing through. It is settling in, reproducing, and pushing steadily northward in a pattern that mirrors some of the most dramatic biological range shifts of our warming century.

The story begins with climate change, the invisible engine behind so many modern biological invasions. Global temperatures have already climbed roughly 1.0 °C since pre-industrial times and are expected to reach 1.5 °C within a few decades. As extreme weather events intensify and habitats transform, countless species are shifting or expanding their ranges to survive. In Europe, this has produced a measurable surge in non-native species, many of which are now capable of creating self-sustaining populations far beyond their ancestral territories. What makes this phenomenon particularly fascinating is that climate change does not merely push species northward through active natural expansion — it also removes the climatic barriers that once prevented introduced populations from surviving. A species can hitchhike into a new country through global trade and, thanks to warming conditions, find itself suddenly able to complete its entire life cycle there. Hungary, sitting in the middle of Central Europe and strongly affected by climate change, has seen a steady stream of such arrivals in recent years.

For decades, the mantid fauna of Hungary consisted of exactly one species: the European mantis, Mantis religiosa, a native of the country and Central Europe at large. Then, in recent years, a second species arrived — Hierodula tenuidentata, a non-native Asian mantid that spread rapidly across Hungary and much of Europe. Shortly after, in 2020, researchers Szinetár and Kenyeres reported something even more surprising: a single male specimen of Ameles spallanzania found in the back of a car, most likely introduced with nursery plants purchased at a gardening centre in Szombathely, western Hungary. At the time, it seemed like an isolated incident, a curiosity rather than a colonisation event. The authors of that earlier study advised that presence-absence surveys in natural habitats would be important to determine whether the species had truly arrived.

The new research answers that question emphatically. Led by a team of Hungarian entomologists, the study compiled data from an impressive array of sources, including large social media groups specialised in arthropod identification, popular citizen science websites such as izeltlabuak.hu (a Hungarian platform with nearly 500,000 arthropod records by the end of 2024), iNaturalist.org, and the GBIF database. The team asked observers for exact localities and collecting information, and in two cases managed to obtain physical specimens for verification. All collected individuals were preserved and deposited in the Collection of Smaller Insect Orders of the Hungarian Natural History Museum in Budapest, ensuring that voucher specimens are publicly available for future study.

Identification was based on careful morphological examination. Ameles spallanzania can be distinguished from related Ameles species by the length of its pronotum, which is twice as long as its width — shorter than in other members of the genus — and by its conical eyes bearing a small apical tubercle. The species is much smaller than the other mantids occurring in Hungary, with a body size of only approximately 20 to 40 mm, and its colour can differ from both the European mantis and the Asian Hierodula. These technical details matter because misidentification is a real risk when tracking range expansions of small, cryptic insects, and the researchers took care to verify every record before drawing conclusions.

The results are striking. In total, 34 observations were recorded from across the country, except for its eastern parts. The team gathered information about 45 individuals from 27 localities, spanning multiple years from 2020 to 2024. Crucially, the researchers recorded nymphs from five sightings, sometimes many specimens together. This detail is significant because it suggests that, at least in some cases, the nymphs were not introduced from abroad but hatched locally — evidence that the species is not merely being repeatedly imported but is actually reproducing in Hungarian soil. Adults and nymphs were found simultaneously in a garden at Tata in northwestern Hungary in consecutive years, confirming local establishment.

Perhaps the most compelling evidence came in November 2024, when three oothecae — the protective egg cases characteristic of mantids — were found on the stems of four small rose plants during their removal in Budapest. Two oothecae of the native European mantis were found alongside them. This discovery indicates that Ameles spallanzania can reproduce in certain urban conditions in Hungary, laying its eggs on common garden plants. The researchers also documented an ootheca laid by a captured specimen in captivity, providing visual confirmation of the species’ reproductive capacity in the region. Females of A. spallanzania can lay up to six oothecae in their lifetime, one every two weeks — a reproductive output comparable to that of Hierodula tenuidentata, which has already colonised most of Hungary.

The study’s authors are careful with terminology, and the distinction matters. Ameles spallanzania is an allochthonous species in Hungary, meaning it originates from a different ecosystem and occurs outside its natural range. This term is not to be confused with invasive species, which implies rapid spread causing environmental or economic harm. The researchers conclude that this mantid does not meet the criteria for invasiveness, so it can only be referred to as a non-native species without raising serious conservation concerns — at least for now. The question of whether it might become invasive out of an established allochthonous species remains open, and the establishment is too recent to draw concrete conclusions about its ecological impact.

What factors are driving this expansion? According to earlier research, two forces significantly help the dispersal of Ameles spallanzania: climate change, particularly the rise of annual temperature and minimum winter temperature, and man-made corridors such as railways and roadsides that serve as dispersal highways. However, there is a crucial biological constraint: females of this species are brachypterous, meaning they have reduced wings and cannot fly, while males can only fly short distances. This means that global trade and transport — especially in the form of oothecae attached to nursery plants — could significantly accelerate its dispersal. The species thrives in most environments with even a minimum level of vegetation and can adapt its life cycle according to geographical latitude, reacting to corresponding temperature changes. Urban conditions seemingly provide particularly suitable habitat, a pattern often observed in the early stages of biological invasions known as the ‘urban heat island’ effect, where milder urban microclimates create favourable environments for warm-adapted species to overwinter and establish populations.

The parallel with Hierodula tenuidentata is instructive. That species, first recorded in Hungary in 2019, followed a strikingly similar trajectory: individual specimens observed at first, then local establishment, then widespread commonness. The first observations came mostly from gardens and similar urban habitats — the same pattern now seen with Ameles spallanzania. However, the latter is less common and has fewer observations so far, likely due to its smaller size and cryptic appearance. Meanwhile, the native European mantis is also spreading northward, clearly related to climate change and milder winters. Schwarz and Ehrmann have hypothesised that no saturation point has been reached in terms of occupying empty niches by mantodeans in Europe, meaning multiple species could theoretically coexist. Whether Ameles spallanzania will follow the same explosive trajectory as its Asian cousin remains to be seen, but the growing number of observations suggests continued expansion towards Central Europe. The researchers have proposed a Hungarian common name — Spallanzani-törpemanó — to aid citizen science monitoring and raise public awareness. For now, this Mediterranean dwarf mantis has firmly planted its flag in the Carpathian Basin, and the warming climate shows no signs of slowing its advance.

Subject of Research: Establishment and spread of the Mediterranean mantid Ameles spallanzania in Hungary

Article Title: New sightings reveal establishment and spread of the allochthonous mantid Ameles spallanzania Rossi, 1792 in Hungary ( Insecta , Mantodea )

Article References: Székely, Á., László, M., Mészáros, Á., & Schlitt, B. P. (2025). New sightings reveal establishment and spread of the allochthonous mantid Ameles spallanzania Rossi, 1792 in Hungary (Insecta, Mantodea). Evolutionary Systematics, 9(1), 99-106. https://doi.org/10.3897/evolsyst.9.146658

Image Credits: AI Generated

DOI: 10.3897/evolsyst.9.146658

Keywords: sightings, reveal, establishment, spread, allochthonous, mantid, Ameles, spallanzania, Rossi, Hungary, Insecta, Mantodea