On Today With Claire Byrne on Friday, 24 October 2025, an interesting debate featuring the tension between farming and conservation was aired. The state’s plans to expand its holdings of land protected for nature are opposed by farmers, especially by the Irish Natura & Hill Farmers’ Association. According to its new president, Pheilim Molloy, the amount of land purchased by the National Parks and Wildlife Service for nature conservation from 2010-2023 was: 2020: 272 acres, 2021: 83 acres, 2022: 10 acres, 2023: 1,528 acres.
These lands were “Being bought up at the expense of young farmers…getting access to land,” according to Pheilim Molloy. The state also acquired over 600 acres near the Connemara National Park in 2025. About 7000 acres were bought by NPWS during Malcolm Noonan’s tenure (2020-2024), averaging about €4,200 an acre. This is high nature value land.
This area, located in the Burren, held limestone pavement, scrub and flower-rich grassland before it was destroyed by the landowner.
According to Molloy, the state’s greater purchasing power meant local farmers were outbid. The average farm size in Ireland is c.75 acres, so even the small parcels of land purchased by the state are hampering economic opportunities for local farmers, claimed Molloy.
Hay meadow, Burren National Park. This is a rare habitat in Ireland. It requires specific management and cannot survive intensive farming.
In response, Malcolm Noonan, responsible for NPWS in the previous administration, described the financial schemes available to farmers to support nature conservation, such as those supporting breeding waders and farming in the Burren.
Molloy wants farmers to own the land, and they would apply conservation measures in their farming practices.
Regarding the overgrazing of uplands by sheep, Molloy stated that sheep have been farmed in Ireland for thousands of years.
However, poor management is damaging our habitats, according to Malcolm Noonan. Land abandonment should be avoided, he added, calling for conservation-centred management of semi-natural grassland. Funding is key, but the funding, €3.15 billion Climate and Nature Fund earmarked for nature restoration at scale under the previous Government, has now been redirected to Metro North, a rail system to be located mainly in North Dublin, stated Noonan, who called for adequate funding for farmers to safeguard nature, water and climate.
In our view, the purchase of land to secure important habitats is important but insufficient. The amount of land purchased is tiny. We are emphatic that farmers are not the custodians of biodiversity.
Farming is a business. A business will make choices to maximise profit. Unless care for nature produces profit, most agricultural businesses will ignore it.
Pheilim Molloy’s comments about farmers (in general) taking care of habitats are contradicted by the facts. In 2020, 10% of the Republic of Ireland’s land was used for crops and about 60% was used for grassland, mostly fertilised (CSO, 2022). In the last decade, Ireland lost 30% of its semi-natural grasslands, and more than half of Ireland’s native plants are in decline (Fourth National Biodiversity Action Plan 2023-2030). Concerning farmers caring for the land, consider this statistic: 85 per cent of our internationally important and protected habitats are in poor condition. Most are in private ownership, mostly owned by farmers. Every five years, an update report on the state of Europe’s environment is compiled by the European Environment Agency (EEA). The report is a synthesis of country profiles detailing conditions in each of the 27 European Union member states and 11 neighbouring countries. With regard to biodiversity, the 2025 report on Ireland states that biodiversity “remains under threat and the state of nature is very poor” (EEA, 2025).
Beautiful orchid-rich calcareous grassland in the Burren, Parknabinnia, County Clare.
Ireland ranked bottom among EU member states for expenditure on environmental protection. The EU average was 2.2 per cent of GDP, but Ireland’s expenditure was just 0.9 per cent (EEA, 2025). And Pheilim Molloy wants the state to stop buying high nature value land for conservation purposes.
We need to buy more land for nature, not none, and continue to provide financial support to farmers who manage their land to support biodiversity objectives. We must have more land where nature conservation is the primary objective. In this regard, the purchase by the state of Cullahill Mountain SAC (Special Area of Conservation) is welcome. This land holds the priority habitat, ‘Semi-natural dry grasslands and scrubland facies on calcareous substrates (important orchid sites)’. This important site in north Kilkenny is currently grazed by Dexter cattle to enhance the quality of the habitat. Kilkenny has only eight Special Areas of Conservation, and only one other site contains similar semi-natural grassland in a county with highly intensive agriculture.
Orchid-rich grassland, The Burren.Hay meadow, the Burren. Hay meadows need to be cattle-grazed and cut at the correct times.
The correct management of high nature value land is crucial. The desire of farmers to add to their farms suggests a desire to increase profits, not to care for nature. Unless the need to farm profitably and the need to protect the environment that grows our food are sustainably aligned, our biodiversity will continue to suffer.
The Wood White requires dry, unfertilised grassland/scrub mosaics for its survival.
Imagine reporting to your company’s board that the firm’s business has only a single irreplaceable supplier, who we rarely, if ever, pay, and who is deteriorating and going out of business.
If you are lucky enough to farm high-nature-value land, cherish the treasures you have. Pay your supplier.
The very rare Scarce Crimson and Gold moth only occurs in unfertilised habitats; in Ireland, it occurs mainly in the Burren.
Key References
Central Statistics Office (2022). Environmental Indicators Ireland. Available at: https://www.cso.ie/en/releasesandpublications/ep/p-eii/ environmentalindicatorsireland2022/landuse/(Accessed 27 November 2023).
Butterfly Conservation Ireland manages a reserve for butterflies in Lullybeg, in northwest Kildare. The reserve holds a variety of our scarcer butterflies and moths, as well as common species. The habitats include scrub, woodland, wet grassland (including molinia grassland, a protected habitat under the EU Habitats Directive), ponds, marsh, wet heath, and poor fen and flush. The sunny weather during the spring and summer months benefited our reserve’s butterflies. Vegetation has responded to the conditions during the main growth seasons, showing dense growth that requires management.
The spring was the warmest and sunniest on record, and while summer was the warmest on record too, we received near-average rainfall. The reserve is on peat soil, and the naturally impeded drainage results in conditions that rarely dry out, so that the combined moisture and warmth stimulate a vigorous response from the wetland vegetation. With the increasing density of the grassland posing a conservation challenge, we introduced a tried and tested strategy: cattle grazing.
Cattle graze Lullybeg Reserve, October 2025.Close view of Purple Moor-grass showing evidence of cattle grazing. Note the blunt grass tips.
Eight study cattle were brought in, and these tackled the rank grassland. Cattle breeds used in farming today generally avoid tough grasses, preferring the softer, medium and thin-bladed species they find more palatable. However, cattle will ‘make do’. Our observations showed that the livestock did eat the tough Purple Moor-grass. Cattle will nibble on the leaves of Devil’s-bit Scabious, but this appears to be tentative, and the plant, used by the caterpillars of the Marsh Fritillary butterfly and Narrow-bordered Bee Hawkmoth, is left uneaten. We therefore get the benefits of sward density reduction without loss of important foodplant resources.
Devil’s-bit Scabious in bloom in wet grassland, 25 August 2025.Marsh Fritillary larval nest in Lullybeg Reserve, 25 August 2025.
Cattle do more good than reducing sward heights and maintaining sward structure. Cattle also trample dense growth, breaking it up and opening the sward. This creates bare ground and disturbs soil, especially where poaching occurs around congregation points, leading to the development of wet flushes and shallow water, adding to the small-scale diversity crucial for biodiversity. Small-scale diversity is increasingly scarce in our farmed and abandoned land, and this reduction in structural diversity is negative for nature. In addition, some wetland flora cannot withstand denser, closed swards on peat soils and are lost if near bare and sparsely vegetated soils are lost from a site. We have found that Sheep’s Sorrel and Cuckooflower disappear when bare areas are lost.
Herb-rich wet grassland in flower in Lullybeg Reserve, 3 August 2025.Narrow-bordered Bee Hawkmoth caterpillar on Devil’s-bit Scabious.
The cattle also fed on and poached the elevated, drier ground, which has ensured that these areas now have more bare soil. This action allows important plants like Common Bird’s-foot-trefoil to thrive, while surrounding bare areas heat up in sunshine, warming the soil and adjoining foodplants, increasing their attractiveness to gravid female butterflies and moths. The bare sites are also used as resting and basking sites for butterflies.
The Common Blue uses Common Bird’s-foot-trefoil in Lullybeg. This male was seen on 31 May 2025.
The cattle were happy too, enjoying a fibre-rich, unfertilised, wild diet in a quiet, sheltered grass/woodland mosaic.
This management will allow sights like those following to continue to be enjoyed.
A special thanks to Michael Jacob, Chairman of Butterfly Conservation Ireland, for arranging the grazing and to Philip Doyle for providing the livestock.
Fox Moth caterpillar on Meadowsweet, Lullybeg Reserve, 21 September 2025.A male Comma feeding on Devil’s-bit Scabious, Lullybeg Reserve, 23 September 2025.Lullybeg Reserve showing semi-natural woodland containing Scots Pine, Downy Birch and Grey Willow.A lovely male Brimstone takes a late sip from Devil’s-bit Scabious on Lullybeg Reserve, 21 September 2025.Peacock, Lullybeg, 18 July 2025. Dense grassland and scrub remove nectar sources needed by this long-lived, overwintering adult butterfly.The Small Copper foodplant in Lullybeg (Sheep’s Sorrel) needs bare ground to germinate. This Small Copper was seen in Lullybeg on 18 July 2025.A female Emerald Damselfly in Lullybeg Reserve, 18 July 2025. This species particularly likes shallow water found in Lullybeg Reserve.
According to the European Union, the main causes of biodiversity loss are changes in land use (e.g. deforestation, intensive monoculture, urbanisation), direct exploitation such as hunting and over-fishing, climate change, pollution and invasive alien species.
This post selects examples of biodiversity loss from land use changes (deforestation), climate change, pollution (agricultural intensification: use of chemicals), and invasive alien species.
White-tailed Sea Eagles killed by Wind Turbines
As the Irish state embarks on ramping up wind farms, three White-tailed Sea Eagles have been killed by turbines in south Donegal in the past 12 months. Despite this, an application has been made in the region for more, bigger turbines with an increased tip height (maximum tip height of between 149.4m and 149.6m). So much for the collision risk modelling, which predicted just 0.09 collisions per year — equivalent to one bird killed every 10.8 years. The silence about this is deafening.
The state’s ramping up of wind farm developments, a move mandated by the European Union, will see the rubber-stamping of wind turbines in selected areas.
An area of forestry in County Cork dating back two centuries, roughly the equivalent of eight pitches at Croke Park, has allegedly been illegally felled in recent weeks, according to preliminary inquiries carried out by the National Parks and Wildlife Service, the state body for the country’s wildlife and habitats. The area that held the wood comprises over 30 acres.
Malta has apparently lost four butterfly species, all in the last few years: Brown Argus, Small Copper (last recorded in 2017), Speckled Wood (last recorded in 2020) and Small Heath (last recorded at Ghadira Reserve in 2013), according to reliable observers in the Maltese Islands. All were common until recent decades. A warning of their likely extinction was given in 2018. Suggested causes for Small Copper decline are habitat degradation, which could stem from dumping, excessive pesticide use and, potentially, perturbations resulting from prolonged arid spells and severe climatic episodes that lead to a mismatch (‘out-of-sync’ phenomenon) between life-cycle stages and the availability of resources for foraging and egg laying by the adult, and suitable food-plants for the larvae.
Source: LOUIS F. CASSAR A REVISION OF THE BUTTERFLY FAUNA (Lepidoptera Rhopalocera) OF THE MALTESE ISLANDS. Naturalista sicil., S. IV, XLII (1), 2018, pp. 3-19
In Ireland, declines for the Small Copper, Speckled Wood and Small Heath during 2008-2024 are -68%, -71% and -79% respectively. Are these butterflies heading for extinction here, too?
Source: Judge, M and Lysaght, L.(2025). The Irish Butterfly Monitoring Scheme Newsletter, Issue 17. National Biodiversity Data Centre.
Invasive Alien Species Range Extension
Asian Hornet, a non-native invasive predator of invertebrates, including honeybees and butterflies, has now been sighted in Belfast, following sightings in Cork and Cobh. This species arrived in France in 2004 from pottery imported from China. Despite considerable eradication work, it has not been removed from France, is spreading in Britain and has spread elsewhere in Europe.
Considering the spring and summer of 2025 were the warmest on record, one might expect record numbers of butterflies. Findings from the UK Big Butterfly Count, which took place in July and August 2025, do not support this expectation. Too much damage has been and continues to be wrought on our landscapes for real recovery. The National Biodiversity Data Centre report on the findings of the Irish Butterfly Monitoring Scheme for 2025 will make interesting reading.
Butterfly population abundance reflects the health of our air, water, soils and habitats. Low populations reflect environmental despoilation. Reversing the trend requires local, national and international action. Butterfly populations will not recover without action, no matter how often the sun shines.
A species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The organisms in the complex may be able to hybridise readily with each other, further blurring any distinctions. The Swallowtail butterfly Papilio machaon in the Palaearctic (a biogeographic realm covering Europe, Asia north of the Himalayas, and North Africa) is a species complex. The differences observed in wing characters have led to many subspecies being described, but is there any genetic basis for these designations?
Swallowtail, Malta. Photo J. Harding, October 7, 2025.
We can be confident that the Large White Pieris brassicae is distinct from the Small White Artogeia rapae, based on a range of taxonomic indicators. The appearance of the adults provides separation features: differences in size, markings, and colour are significant. Egg-laying behaviour differs: the Large White lays eggs in groups, the Small White lays singly. Larval behaviour differs: the Small White larva is solitary, the Large White larva is social, the Small White larva is usually concealed, while the aposematic (showing markings warning of danger or unpalatability ) Large White larvae feed in the open. The larval colour differences are also distinctive. Furthermore, the Small White larva is edible to birds, the Large White is distasteful, despite sharing the same larval food.
Chalkhill Blue male, Rodborough Common, Gloucestershire. Photo J. Harding, 21 July 2018.
These differences are easily observed. However, in other species, such as the Chalkhill Blue, differences are far less obvious. However, genetic analysis is helping to separate species that look identical or nearly identical. The Chalkhill Blue Lysandra coridon contains 84-92 chromosomes. The Macedonian Chalkhill Blue Lysandra phillipi, which occurs only in northern Greece, on Mount Pangeon and Phalakron, has only 20-26 chromosomes. Differences in appearance are slight, and specimens are often indistinguishable.
Many species include several subspecies. Subspecies is a rank below species, and refers to a population occupying a distinct area, separate from others of the same species and having constant and clearly different characteristics. However, size differences (among other differences), despite appearing significant, are not always reliable in distinguishing one animal from another.
A recent study, which assessed 40 subspecies of Papilio machaon in the Palearctic, simplified these to 14 subspecies (Nazari et al., 2023). A more recent study (Cassar et al., 2025), aimed at testing the taxonomic boundaries and relationships in the Western Palaearctic (Europe, N. Africa, Middle East) using whole-genome data of taxa (taxa are any biological unit species, subspecies or form or group of units such as genus, family, etc) from the Mediterranean region, which include first draft genomes of the Corsican Swallowtail Papilio hospiton and Desert Swallowtail Papilio saharae. Louis Cassar and his colleagues refined the species boundary of P. machaon and confirmed that the Desert Swallowtail, which closely resembles P. machaon, is a separate species, P. saharae, not a subspecies of P. machaon.
The study assessed the subspecies limits of Mediterranean P. machaon and P. saharae through Bayesian multispecies coalescent inferences (a statistical method used to estimate species trees and other evolutionary parameters, such as population sizes and divergence times, by modelling gene trees within a species tree framework) and population genomic analyses, indicating that a taxonomic simplification is needed, with the exclusion of P. machaon from North Africa (P. saharae mauretanica Verity, comb. nov.) and the synonymy of subspecies (P. saharaeneosaharae Tarrier, syn. nov.). Common Swallowtail, therefore, does not occur in North Africa .
(Note: comb. nov refers to the formal renaming of an organism’s scientific name when it is transferred to a different genus, reclassified within a different species, or its taxonomic rank is altered; syn. nov.” stands for “new synonym”, used when a newly described species or other taxon is found to be identical to a previously named, but different, taxon. The older name is then considered the valid one, and the newer name is placed into synonymy with it.)
The study revealed heterogeneous (diverse) levels of heterozygosity (which refers to the presence of different alleles (versions of a gene) at a particular locus (location on a chromosome) in an individual’s genome) between island and continental lineages that warrant further taxonomic actions. They also found evidence of low gene flow between the Common Swallowtail in Corsica P. machaon, and the Corsican Swallowtail P. hospiton, endemic to Corsica and Sardinia. They discussed how the speciation (evolutionary process by which populations evolve to become distinct species) and phylogeographic patterns are in line with past climatic and geological changes of the Mediterranean Basin.
Although P. machaon is now excluded from North Africa, P. saharae has not been excluded from Europe. Indeed, the swallowtail on Lampedusa Island (Italy) has been designated as a subspecies of the Saharan Swallowtail, P. saharae aferpilaggi. The habitats on Lampedusa are like those in Malta, Sicily, and southern Italy. It breeds on different members of the carrot family than those used by P. machaon, which mainly uses Fennel Foeniculum vulgare and Fringed Rue Ruta chalepensis in southern Europe and Milk Parsley Peucedanum palustre further north. P. saharae might be found in Sicily; this is not yet confirmed.
Swallowtail caterpillars have a forked, fleshy, eversible organ, the osmeterium, concealed within the first thoracic segment. It produces this when alarmed, together with an unpleasant odour to deter predators. The larva of P. machaon has an orange osmeterium, while the larva of P. saharae is brown and twice as long.
There are morphological differences that can help to distinguish P. machaon and P.saharae. The larvae of the Saharan Swallowtail and Common Swallowtail species complex show differences in appearance. Regarding adults, 30–31 antennae segments are found in P. saharae and 33–36 segments in P. machaon. Many specimens of P. s. aferpilaggi were found to have between 29 and 35 antennal segments, with most specimens toward the lower end of the range. The genetic analysis indicates that this taxon is distinct from P. machaon and other P. saharae subspecies, but also that it is a subspecies of P. saharae. The brood structure of P. machaon and P. saharae differs, but at least some differences might be governed by climate and weather.
Mainland P. machaon specimens from Spain, Southern France, Romania, Lebanon and Israel are genetically very uniform, which correlates with the hypothesis proposed by Nazari et al. (2023), placing all these populations in a single subspecies, P. machaon aestivus.
Specimens from Sicily and Malta are differentiated from P. m. aestivus confirming the validity of subspecies P. m. sphyrus. The samples from Sicily and Malta are slightly differentiated from each other, but there are no constant, definable morphological characters to separate these populations. The genomes of specimens from Corsica are genetically close to those of subspecies P. m. sphyrus rather than P. m. aestivus, which needs further investigation. Previously, Corsican machaon has been placed with P. m. emisphyrus Verity (type locality Florence), which is considered by Nazari et al. (2023) as a synonym (the same as) of P. m. aestivus. Cassar et al. (2025) state that additional samples from mainland Italy are needed to confirm whether the genome of P. m. emisphyrus corresponds with P. m. aestivus or is close to P. m. sphyrus, like the Corsican samples.
The specimens from Crete are supported as a distinct lineage by some analyses (e.g. BPP) and have the lowest genetic diversity leading to a high genetic differentiation compared to other P. m. aestivus populations, but again, further samples are needed to clarify the taxonomic status of Crete machaon. Seyer (1977: p. 105) described subspecies P. m. ruettimanni from ‘Kreta, Karpathos und Rhodos’ but designated the holotype from Rhodes (holotype is a single type specimen upon which the description and name of a new species is based). Additional samples from Rhodes, and preferably also other islands and Southwest Turkey, are needed before application of a name to the samples from Crete. Nazari et al. (2023) placed P. m. ruettimanni as a synonym of P. m. aestivus, but the results of the 2025 study suggest that at least the Crete population is significantly different.
Overall, the study simplified 14 Common Swallowtail subspecies in the Western Palaearctic, proposing the following subspecies.
Papilio machaon Linnaeus, 1758; Systema Naturae (Ed. 10), 1: 462; TL: Europæ [= Sweden].
ssp. gorganus Fruhstorfer, 1922; TL: Germania, Austria. Europ. centr.
ssp. aestivus Eimer & Fickert, 1895; TL: Beirut.
ssp. sphyrus Hübner, [1823]; TL: not stated [= Sicily].
ssp. melitensis Eller, 1936; TL: Malta.
Nine taxa that were formerly recognised as subspecies (such as ssp. hispanicus) are absorbed under ssp. aestivus.
Cassar et al. (2025) propose three subspecies of Papilio saharae in the Mediterranean region (saharae, mauretanica and aferpilaggi)
The study looked at phylogeographical factors. Phylogeography is the field of study that combines genetics and geography to understand how evolutionary processes have shaped the geographic distribution of lineages. It examines the genetic structure of populations in relation to their spatial distribution, helping to reconstruct the historical processes (such as sea level changes, climate change) that have led to the current patterns of biodiversity.
The study found that P. m. sphyrus (Southern Italy to Sicily) and P. m. melitensis (Malta) diverged between 3000 and 6500 years ago, which is after the last glacial maximum ended. The central Mediterranean area also experienced the influence and perturbations caused by marine regressions, isolation, and influx from continental landmasses. As a result, there are marked biogeographical affinities between Sicily, the Maltese Islands and continental Italy, given the physical connection that occurred between them at various times during the Pleistocene. The last physical connection between Sicily and Malta is known to have taken place during the last glacial maximum, approximately between 30,000 and 14,000 years ago, after which any form of physical connection vanished, thus leaving Malta isolated. Although P. machaon is reluctant to cross seaways (Grech et al., 2024), the study results suggest the colonisation of Malta could have occurred through overwater dispersal.
Intriguingly, the study indicates that differences in wing shape are not necessarily indicative of genetic differences. The taxon Papilio saharae neosaharae, distinguished by a narrower, elongate forewing compared to P. s. saharae, was found to be genetically indistinguishable from P. s. saharae and is treated as a synonym (syn.nov.) by Cassar et al. (2025). This difference in wing shape can be the result of adaptation to Rutaceae (citrus family) as larval foodplant in P. s. neosaharae rather than the use of Apiaceae (carrot family) by P. s. saharae, or the effect of local environmental conditions. Interestingly, specimens also feeding on Rutaceae from SW France, which seem similar to P. s. neosaharae, were genetically identical to local Apiaceae-feeding P. machaon, suggesting that the foodplant may affect phenotype (appearance) to a certain extent.
Finally, in a 2022 study (Damagala & Lis 2022), mitochondrial DNA (mtDNA), 16S rDNA and cytochrome b sequences were used to examine the correlation between the intraspecific classification (classification of individuals within a species, including categories like subspecies, varieties, or forms) and the genetic structure of P. machaon. Most researchers agreed that the population of the Old World swallowtail from the British Isles represents the endemic subspecies britannicus. The 2022 analysis did not show the distinctiveness of the British subspecies from the other European subspecies as proposed by many authors.
The haplotype analyses (haplotype is the set of genes at more than one locus which is inherited by an individual from one of its parents) and the location of European specimens on phylogenetic trees indicate that, despite the significant geographical distances between populations, there is the possibility of a flow of genetic information throughout Europe (including the British Isles). However, the second British specimen in the sample represented unique haplotypes. The study results suggest that the Old World swallowtail is an excellent flyer, and its individuals have no problem moving large distances, enabling the exchange of genes within one large genetic pool throughout Europe and Eurasia.
Common Swallowtail, first generation, Siena, Italy. Cassar et al. 2025 proposed that this is ssp. aestivus, previously known as ssp. emisphyrus. Photo J. Harding, April 2022.Swallowtail from Britain, reared specimen. Damagala & Lis (2023) query its subspecies status. Photo by Peter Eeles. Source: www.ukbutterflies.co.ukThe Swallowtail from the Maltese Islands has retained its subspecies status, ssp. melitensis. Photo J. Harding, October 7, 2025.
Certainly, from my observations, the adult is a formidable flyer, capable of sustained, powerful flight when it can cross several kilometres without stopping. It often appears in areas with few nectar or foodplant resources, indicating its strong dispersive and migratory tendency. Individuals who are dispersing fly with speed and are impossible to follow. Its beauty, highly variable appearance and charismatic behaviour have long charmed lepidopterists, including this one. Ireland is alone in Europe in lacking this butterfly. The warming climate might result in colonisation. I doubt that anyone will object.
Note: Responses awaited from the corresponding author of the study, ‘Whole-genome data shed light on speciation and within-species differentiation of the Papilio machaon complex around the Mediterranean Basin’, may result in amendments to this article.
References
Cassar, F., Nabholz, B., Reboud, E. L., Chevalier, E., Lafon, B. J., Cotton, A. M., & Condamine, F. L. (2025). Whole-genome data shed light on speciation and within-species differentiation of the Papilio machaon complex around the Mediterranean Basin. Systematic Entomology, 50(4), 692-712. https://doi.org/10.1111/syen.12675
Domagała, P.J.; Lis, J.A. One Species, Hundreds of Subspecies? New Insight into the Intraspecific Classification of the Old World Swallowtail (Papilio machaon Linnaeus, 1758) Based on Two Mitochondrial DNA Markers. Insects 2022, 13, 752. https://doi.org/ 10.3390/insects13080752
Grech, N., Cassar, L.-F. & Gauci, A. (2024) Use of telemetry to monitor the movements of Papilio machaon (Lepidoptera Papilionidae) and Chamaeleo chamaeleon (Squamata Chamaeleonidae). Naturalista Siculo, 48, 61–70.
Nazari, V., Cotton, A.M., Coutsis, J.G., Shapoval, N., Todisco, V. & Bozano, G.C. (2023) Guide to the butterflies of the Palearctic region. Papilionidae part IV, subfamily Papilioninae, tribe Papilionini, genus Papilio (Partim). Milan: Omnes Artes s.a.s, p. 91.
