South Africa’s rare butterflies

The Lepidoptera Log - by Steve Woodhall

The 'Red Zone'

75 of our butterflies are in trouble.

Recently I was sent a copy of this paper: Recent butterfly extinctions in Sweden reveal the inadequacy of site-based protection and the need for landscape-scale management

The three species it mentioned were all IUCN Red Listed and at the extreme northern edge of their European distributions. This made them vulnerable to random changes in their environment pushing them into extinction. This paper shows the importance of well managed citizen science programs like iNaturalist and the Butterfly Monitoring Scheme in providing conservation information on butterfly populations, because the authors relied on such data to support their findings.

Our local butterflies share those vulnerabilities but there are many more of them – 75, to be exact. A paper I recently co-authored with Ernest Pringle (Why is South Africa so rich in butterfly species and why are so many of them endemic?) proposes some possible reasons for this.

Fortunately, in South Africa we have a handle on this. IUCN, the International Union for Conservation of Nature, has a system of categorising living organisms according to the threats to their continued existence. It publishes and maintains the Red List of Threatened species.

The Red List has these categories:

Data Deficient (DD)
Least Concern (LC)
Near Threatened (NT)
Vulnerable (VU)
Endangered (EN)
Critically Endangered (CR)
Extinct in the Wild (EW)
Extinct (EX)

The categories in red are those regarded as ‘threatened.’ As we go down the list the threat of extinction increases.

What does that mean for our South African butterflies?

The Lepidopterists’ Society of Africa teamed up with the South African National Biodiversity Institute (SANBI) to assess all 805 of our butterflies (this includes all local races or subspecies). The five criteria used were:

A. Population size reduction
B. Geographic range in the form of either B1 (extent of occurrence) AND/OR B2 (area of occupancy)
C. Small population size and decline
D. Very small or restricted population
E. Quantitative Analysis of probability of extinction in the wild

Scores were allocated scientifically to each of these to calculate the categorisation using the IUCN’s rule book. It was a lengthy process and the people who did it were dedicated to the job. This is what we found:

One butterfly is Data Deficient
719 are Least Concern, which sounds like a relief, but it means that nearly 11% ARE of concern!
However, within ‘LC there are four other subcategories in the South African National Red List – ‘Extremely Rare‘, ‘Rare – Habitat specific’, ‘Rare – Low Density’. and ‘Rare – Restricted Range‘. What separates these from ‘Data Deficient’ is a matter for debate. A couple of examples are shown below.
Seven are Near Threatened, which means that slight changes in circumstances could push them over into the ‘Threatened’ categories.
Twenty are Vulnerable, which is the lowest ‘Threatened’ category and with concerted actions they could be preserved.
Thirty are Endangered. This means that only a few changes to the threats could push them over the edge to extinction.
Twenty-five are Critically Endangered. This means that they are close to the edge and require urgent, targeted action to arrest their decline. Of those twenty-five, five fall into a special category:
Critically Endangered – Possibly Extinct. That means they haven’t been seen for a long time but not for the fifty years that would make them officially…
Extinct. Gone, never to return.

The Society has instituted a program called COREL (Custodians Of Rare and Endangered Lepidoptera). A custodian has been allocated to each of the Critically Endangered species.

We could not hope to cover all 75 species in one blog post. Should you wish to see the original assessments they are here, here, here, here, and here

Let's look at a few examples

Data Deficient

Golden Giant Cupid, Lepidochrysops penningtoni is a rare little butterfly from Namaqualand. Its wingspan is only 25-36mm so you might ask how it came to be a ‘Giant’ Cupid; the answer is that some members of this genus really are ‘Giant’ as blues go. The ‘type locality’ is north of Steinkopf in the Northern Cape, which is where the specimen on the right was photographed. Populations exist further south in areas around Kamieskroon, which is where the left hand specimen was photographed. They are so uncommon and we know so little about their habits and biology that their Red List assessment results are too vague for a category to be assigned.

Least Concern but Rare

56 of our ‘Least Concern’ species are categorised nationally under one of four ‘Rare’ subcategories. These have no global Red List status because for various reasons they don’t qualify under any of the five required criteria for that. It does however flag these butterflies for local conservation attention. Here are a few examples.

Langeberg Skolly, Thestor pictus inhabits a tiny patch of rare fynbos in the Langeberg Mountains that is only 3.3 square kilometers in extent, but because it is inside a managed nature reserve its threat level is low. It is categorised nationally as Rare – Restricted Range, Habitat Specialist.

Millar’s Large Buff, Deloneura millari is categorised as ‘Rare – Low Density’ because it is a secretive, skulking butterfly that is seldom seen out in the open, like this one was. They spend most of their time hiding in the foliage feeding on honeydew secreted by scale insects (Bugs). They are reluctant to take wing. Tapping the branches of trees sometimes startles them into flight. If this happens they usually move quickly back into the leaves and refuse to be flushed again. They are quite widespread but this behaviour makes it difficult to work out the true extent of their range.

Natal Yellow-banded Sapphire, Iolaus diametra natalica is categorised nationally as ‘Rare – Low Density’. Scattered populations exist across northern KwaZulu-Natal. It might be less rare than originally thought because of its secretive, skulking habits.

Southern Forest-king Charaxes, Charaxes xiphares occidentalis is only found in tiny patches of Southern Afrotemperate Forest in the Grootvadersbos Nature Reserve. It is nationally classified as Extremely Rare

Near Threatened

There are five butterflies in this category. They all have a limited range but some have a wider range at species level. ‘Near Threatened’ species may become vulnerable to endangerment in the near future, but they do not currently qualify for the threatened status under any of the five criteria.

Bicoloured Paradise Skipper, Abantis bicolor is rare and restricted to fragmented Scarp Forests within the Pondoland and Indian Ocean Coastal belts. It ranges from East London to Eshowe. Many of its localities are under threat from development and agriculture. Because it is found inside protected areas like Dlinza and oNgoye forests, and Krantzkloof Nature Reserve, its conservation status is secure enough to keep it out of the higher categories.

Witsand Ciliate Blue Anthene lindae is found over a wide range of arid Northern Cape savanna at a low density. It is only known from four locations (which are inside protected areas) in a region prone to severe droughts and excessive groundwater extraction for agriculture, hence its Near Threatened category.

Southern Large Glasswing Ornipholidotos peucetia penningtoni is restricted to the far northeast of Zululand. It was thought that it only inhabited Swamp Forest but recently populations have been discovered in wooded lowveld savanna near Eshowe. It is found in southern Mozambique. The nominate subspecies is found in eastern Zimbabwe and northern Mozambique and is more widespread.

Wakkerstroom Widow Dingana alaedeus is a rare montane grassland species found in northern KwaZulu-Natal and southern Mpumalanga. It is found on rocky hillsides of little grazing value, so agriculture is not a high threat. However, that entire area is of interest to the mining industry for its minerals.

Vulnerable

There are twenty butterflies in this category. ‘Vulnerable’ (VU) is the lowest category of threatened species. It means that the organism meets one of the five Red List criteria mentioned above. It is thus considered to be at high risk of human-caused extinction without further human intervention

White-spotted Sapphire Iolaus lulua is categorised as VU B1ab(iii). It has a limited geographic range with few locations. Although some of its populations are in protected areas (such as False Bay Park in Zululand) its numbers are declining and the habitat is fluctuating in quality due to drought and agricultural pressure.

Greyton Dark Ranger Kedestes niveostriga schloszi is also categorized as VU B1ab(iii). It was previously categorized as Endangered because its sole population near Greyton was declining due to growth of the town. Since then, two new subpopulations have been discovered by its custodian, and these are in well-protected, wild areas. However, its limited range and the threat of alien vegetation encroachment in all its locations mean it still falls under criterion B1.

Diamond Opal Chrysoritis trimeni is categorised as Vulnerable under criterion D2. It has an exceedingly small range in the Namaqualand coastline near Kleinsee where it is under threat from alluvial diamond mining of its sand dune habitat. Further threats stem from urbanization of Port Nolloth and McDougall’s Bay.

Estcourt Giant Cupid Lepidochrysops pephredo falls under category VU B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v). Its range is small and shrinking and its habitat is becoming increasingly fragmented. It is known from a few small isolated patches of mistbelt and highland grassland in the Midlands of KwaZulu-Natal. Only one of these is inside a formally protected area. The main threats are overgrazing and, in some areas, human settlement. Its custodian has informed local farmers of its presence and encouraged them to avoid overgrazing and other harmful land use practices like frequent fires.

Southern Amakosa Rocksitter Durbania amakosa albescens is categorised as VU B1ab(i,ii,iii,iv). Its extent of occurrence (B1) is limited, and it is in a severely fragmented or few locations (a) with a continuing decline (b) in extent of occurrence (i), area of occupancy (ii), area, extent, and/or quality of habitat (iii), and number of mature individuals (iv). Its caterpillars feed on lichens growing on rocky patches in moist grassland. It is a sedentary species that is under particular threat because movement between colonies is becoming increasingly unlikely as a result of urbanization of its habitat, potential mining, and unsustainable grazing practices that strip the rocks of the protective grasses that provide shelter for the larvae.

Zulu Yellow Buff Teriomima zuluana is categorized VU B1b(ii,iii)c(ii). Its range (Extent of Occurrence) is less than 20 000 km². There is a continuing decline in its area of occupancy (suitable habitat – condition ‘b’) and a decline in the quality of that habitat. Extreme fluctuations have been observed in its area of occupancy. It is a low density, secretive, rare butterfly found only in the lowland forests and thickets of the northern KwaZulu-Natal and southern Mozambique Maputaland area. Although some populations are in protected areas all of them are under threat from factors such as forest clearance, agriculture, and mining for sand minerals such as titanium.

Piketberg Mintha Veined Widow Torynesis mintha piquetbergensis is categorized VU D2, like the Diamond Opal. It is severely range restricted (Extent of Occupancy 5 km²) on the slopes of the Piketberg and nearby hills. Its range has been reduced by extensive wheat farming in the area. Insecticides used by the farmers are a particular threat because its larvae feed on grasses. Its taxonomic status needs to be revised since its appearance is quite different to the nominate subspecies, which is a widespread butterfly.

Red Hill Russet Aloeides egerides is categorised VU B1ab(iii), a similar subcategory to the Greyton Dark Ranger, but unlike that butterfly it has not had new locations discovered. The opposite in fact – it hasn’t been seen at its type locality at Red Hill for many years and its other five locations (all in scarce low elevation fynbos vegetation) are under severe threat from inappropriate fires, informal housing developments, and the spread of invasive alien plants. A search for additional subpopulations is underway by its custodian, but this is hampered by lack of knowledge about its ecological requirements.

Endangered

Thirty species of South African butterflies fall into this category so again we can only show a small sample here. The main difference between this category and ‘Vulnerable’ is the severity of the risk of extinction. Endangered species face a “very high risk,” while Vulnerable species face a ‘high risk’ of extinction in the wild. This difference is reflected in the quantitative thresholds for each criterion, where the criteria for ‘Endangered’ require a more severe rate of population decline, a more restricted geographic range, or a larger probability of extinction within a specific period compared to the criteria for ‘Vulnerable.’

It’s important to realise that a species’ threat category can change over time. New threats may emerge, like climate change or the discovery of a new mineral ore body under one of the main locations. Our knowledge of the species may also change; new locations may be discovered. Its taxonomic status may be modified if new evidence of its relationship with related species is uncovered, for example by use of DNA technology.

Toothed Russet Aloeides dentatis dentatis is currently categorized as EN B1ab(iii)+2ab(iii); C2a(i). Originally it was thought to be confined to the Ruimsig Entomological Reserve in Roodepoort, Gauteng, but populations were found along and adjacent to the Witwatersrand and Suikerbosrand mountain ranges near Heidelberg in Gauteng province and eastwards to around Delmas in Mpumalanga province. The status of the subspecies Aloeides dentatis maseruna from the Free State may change and there are several butterflies found in montane grassland to the east that may prove on DNA evidence to be the same species. Ongoing DNA research continues and this butterfly’s Red List status may change in future.

De Hoop Scarce Silver-spotted Copper Trimenia malagrida maryae is one of the subspecies of Trimenia malagrida, most of which are Critically Endangered. Its category is EN B1ab(i,ii,iii,iv,v). This taxon may also be categorized as such because an extremely limited range of only 1369 km² and only three scattered locations, at two of which it has not been seen for at least ten years (including its type locality De Hoop Nature Reserve). Encroaching alien vegetation has recently become a serious threat.

Worcester Opal Chrysoritis rileyi is categorized as EN B1ab(iii)+2ab(iii). It is found in lowland fynbos in valleys near Worcester in the Western Cape. Its status until recently was Critically Endangered but a large new population was discovered which increased its range by a factor of fourteen and its area of occupancy by a factor of ten (but they are still small enough to warrant Endangered status). Dam expansion and agricultural activity remain threats, as does the encroachment of alien vegetation.

White-spotted Ketsi Giant Cupid Lepidochrysops ketsi leucomacula is categorized as EN A3bc; B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v). The threats faced by this butterfly are severe. It only occurs in the coastal grasslands of south-eastern KwaZulu-Natal province and north-eastern Eastern Cape province. It’s threatened by urban and rural development and overgrazing at most of the unprotected localities where it occurs, as well as other local threats at individual unprotected sites. Certain habitats in Margate where it used to occur, including at the type locality, have been destroyed by urban and agricultural development, and local extinction has resulted at those sites. Its conservation assessment makes for sobering reading because climate modelling has shown that it may lose most of its habitat to bush encroachment by 2050.

Karkloof Blue/Cupid Orachrysops ariadne is categorized EN B1ab(iii)+2ab(iii). There is some better news about this butterfly, which is found in four small subpopulations in Midlands Mistbelt Grassland on relatively moist and cool south-facing slopes. The land occupied by the largest subpopulation near Merrivale was purchased by a LepSoc member and donated to Ezemvelo KZN Wildlife which is working hard to manage the ecosystem sustainably. The other locations are either inside existing protected areas or private nature reserves where the owners are aware of its presence and are committed to preserving it. However, eventually, climate change and bush encroachment, and invasive vegetation, remain threats.

Yellowish Amakosa Rocksitter Durbania amakosa flavida is categorized as EN C2a(i) and is found in moist grassland amongst rocks which function as a substrate for lichens upon which the larvae feed, mostly west of Durban. There were fifteen subpopulations at nine locations but one of these, near Nkandla Forest, has proven to be the more widespread inland subspecies Durbania amakosa natalensis which is categorized as LC. Although one new subpopulation of flavida was recently discovered south of the Outer West of Durban, many of its locations in that area are severely threatened by urbanization. There is however one subpopulation inside the well protected Krantzkloof Nature Reserve.

Southern Induna Telchinia Telchinia induna salmontana is categorized as EN B1ab(iii,v)+2ab(iii,v). This butterfly is found in exposed, high, rocky ridges in mountain sourveld on the Soutpansberg of Limpopo Province. It has a very small range and only four locations, only one of which is protected in a nature reserve. Habitat modification by fire, forestry and human settlements are threats; there is ongoing decline in the number of mature individuals despite there not being apparent habitat destruction. Some localities have been modified by alien vegetation and human interference.

Midlands Widow Dingana dingana is categorised as EN B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v). It is found in Gs8 Mooi River Highland Grassland, usually among large dolerite or sandstone boulders, at an altitude of 1 300 m to 1500 m. None of its subpopulations have been found in conservation areas and one, near Mooi River, appears to have disappeared. relevant landowners on farmland should be included in an awareness program. Relevant landowners on farmland were contacted in an awareness program by its custodian.

Critically Endangered

Critically Endangered (CR) species are considered to be facing an extremely high risk of extinction in the wild. The same five measures are used as for the other categories but to qualify as ‘CR’ on the IUCN Red List a species must meet at least one of these criteria:

A 50% or higher chance of becoming extinct in the next ten years or three generations
250 or fewer mature individuals in total
50 or fewer mature individuals per subpopulation
A continuing population decline of 25% or more in three years or one generation
An extent of occurrence (EOO) of less than 100 square kilometers
An area of occupancy (AOO) of less than 10 square kilometers
A population reduction of 70% or more over the past ten years or three generations

Twenty-five of our butterflies meet these criteria within at least one of the measures, which is concerning. Worse, five of them are in an even more threatened subcategory – Critically Endangered – Possibly Extinct. Looking at the species accounts for those it seems as though the criterion is that it has not been seen for more than 15 years and less than 50, which is the cut off for ‘properly Extinct’. And to make it even more complicated one of them turned out to be a ‘Lazarus’ species and was rediscovered during 2022!

Unique Ranger Kedestes lenis lenis is categorised CR B1ab(i,ii,iii,iv,v). It has an exceedingly small range on the Cape Flats where its former habitat has been lost to urban and agricultural development, and the population is severely fragmented. There are four remaining locations. The damp seeps in which the host plant Imperata cylindrica grows are drying out due to groundwater extraction by invasive alien plants and the grass is becoming combustible. Fortunately, Cape Town Metro and the University of the Western Cape have populations in nature reserves they manage well. That said, alien plant encroachment, road building, and problems with fire management are still threats it faces.

Waterberg Acraea Copper Erikssonia edgei is categorised CR B1ab(iii,v)+2ab(iii,v). There is only one location with two colonies, in private nature reserves in the Waterberg. The area has been subject to a recent severe drought and the butterfly, after declining in numbers, seems to have disappeared. Monitoring continues.

Adonis Opal Chrysoritis adonis is one of the most beautiful butterflies in the country and has seldom been photographed in the wild. It’s categorised CR B1ab(i,ii,iv,v)+2ab(i,ii,iv,v). It inhabits the northern slopes of the Gydo Mountain near Ceres where it was found in montane fynbos at altitudes of 1 400–1 500 m above sea level, particularly in flat depressions below rocky ridges. It is difficult to assess the threats faced by this species. These may arise from farming activities near the locality, for example the use of herbicides and pesticides. It has not been seen for several years.

Wolseley Skolly Thestor strutti is categorised as CR B1ab(i,ii,iv,v)+2ab(i,ii,iv,v). It has a tiny range and only one location on the mountain slopes near Wolseley. The general area was under forest plantation, which has subsequently been felled/cleared and the area is now managed by CapeNature. Despite this the numbers have been decreasing when monitored, which may be due to drought.

Brenton Blue/Cupid Orachrysops niobe is probably our best-known and most intensively studied Critically Endangered butterfly species. It is categorised CR A2; B1ab(iii,v)+2ab(iii,v); C1+2a(i,ii); D. It was always rare, being known from only two localities – the Brenton Blue Butterfly Reserve at Knysna and Nature’s Valley, but it has been extinct at the latter since the 1970s. Severe drought reduced the Knysna population by 93% from 2014 to 2017. In 2017 a severe fire devastated the area, and the butterfly has not been seen since.

iNkomasi Protea Capys penningtoni is another butterfly facing severe threats and is reducing in numbers as well as range. It is categorised CR C2a(i). It inhabits Montane Protea savanna within an approximate altitudinal range of 1 000 to 2 100 m in the catchment area of the iNkomasi River. Its larva feeds on the seeds of Protea caffra by boring into the flower heads. It has been decreasing in abundance and is now rare at the sites where it still occurs. Local extinction is close to occurring at several sites where it formerly was relatively abundant, including at the type locality near Boston. An alien invasive Harlequin ladybird beetle that roams the butterfly’s habitat, including its oviposition sites, which is known to feed on lepidopteran eggs, is probably the major threat to the survival of the butterfly species. Other threats, probably operating in synergy, are frequent fires and the increasingly abundant bracken and American bramble affecting the host plant.

Wolkberg Zulu Alaena margaritacea is categorised CR B1ab(iii)+2ab(iii). It is restricted to two subpopulations in the Wolkberg mountain range near Haenertsburg. These are on steep rocky slopes of Woodbush Granite Grassland associated with lichen-covered rocks. When this species was first assessed there was only one locality known, the second only having been discovered in 2013. Both locations fell outside officially protected areas and were threatened by plantations and other factors associated with commercial operations. Through the efforts of the custodian the main site has been proclaimed a special nature reserve and is being intensively managed in attempts to strengthen the population.

Critically Endangered - Possibly Extinct

There are five butterflies in this category. One of them, Swartland Silver-spotted Copper Trimenia wallengrenii wallengrenii, had not been seen for 16 years and had been categorised as CR–PE B1ab(i,ii,iii,iv,v), Then, in 2022, a colony was discovered on top of a granite renosterveld koppie south of Darling in the Western Cape. This was the ‘Lazarus’ species mentioned above. It will now have to be reassessed.

Paarl Silver-spotted Copper, Trimenia malagrida paarlensis is categorised CR–PE B1ab(iii)+2ab(iii). This butterfly was only ever found on Paarl Mountain and Paardeberg Mountain near Paarl. The Paarl Mountain subpopulation is extinct.

The Paardeberg population has not been seen at the last remaining colony since 2010, despite regular surveys. Invasive alien vegetation and inappropriate fire regimes have reduced the quality of the habitat.

Brenton Opal Chrysoritis mithras, categorised CR–PE C2a(ii)b, was until recently regarded as only being found near Knysna. The same 2017 fire that damaged the Orachrysops niobe colony also seemed to have wiped out the type colony of Chrysoritis mithras. However, in a recent revision of the genus based on DNA phylogeny, populations to the west as far as Stilbaai were recognised as not being Chrysoritis mithras (as had been thought) but possibly a new subspecies of it. The specimen illustrated here is from near Witsand. More work is required to resolve this.

Extinct

There are three South African butterfly species that are regarded as being Extinct (Ex). None has been seen for over 50 years, which is the criterion for extinction. There are no live photos of these species available, but there are images of mounted specimens.

Tygerberg Monkey Giant Cupid Lepidochrysops methymna dicksoni used to occur in Renosterveld vegetation on the Tygerberg Hills near Cape Town. It has not been seen for 50 years despite extensive searching in the known localities. These localities are close to longstanding areas of agricultural activity, housing development and quarry activity.

Mbashe River Large Buff Deloneura immaculata was recorded from three females captured by Colonel J.H. Bowker near “Fort Bowker” … “at the end of December 1863”. Numerous undocumented surveys, by a number of butterfly collectors over the last century, for this taxon have been unsuccessful.

Geluksburg Giant Cupid Lepidochrysops hypopolia is only known from Blue Bank near Ladysmith in KwaZulu-Natal, from records in the 1870s. It has not been recollected since then despite a number of searches.

However, the original collector was reputed to have mislabelled bird specimens. There were some dubious records from near Potchefstroom that may have been this species or its close relative Highveld Giant Cupid, Lepidochrysops praeterita. Some historical records may indicate that the true type locality was some remote spot high in the Drakensberg above Geluksburg. Another ‘Lazarus’ species?

The search continues…

Golden Giant Cupid

Golden Giant Cupid

Langeberg Skolly

Millar's Large Buff ♂

Natal Yellow-banded Sapphire

Southern Forest-king Charaxes ♂

Bicoloured Paradise Skipper ♂

Witsand Ciliate Blue ♂

Southern Large Glasswing ♂

Wakkerstroom Widow ♂

White-spotted Sapphire ♀

Greyton Dark Ranger ♀

Diamond Opal ♂

Estcourt Giant Cupid ♂

Southern Amakosa Rocksitter ♂

Zulu Yellow Buff ♂

Piketberg Mintha Veined Widow ♂

Red Hill Russet ♀

Toothed Russet ♀

De Hoop Scarce Silver-spotted Copper ♀

Worcester Opal ♂

White-spotted Ketsi Giant Cupid ♂

Karkloof Blue/Cupid ♀

Yellowish Amakosa Rocksitter ♂

Southern Induna Telchinia ♀

Midlands Widow ♂

Unique Ranger ♂

Waterberg Acraea Copper ♂

Adonis Opal ♂

Wolseley Skolly♂

Dickson's Strandveld Copper ♂

Brenton Blue/Cupid ♀

iNkomasi Protea ♂

Wolkberg Zulu ♀

Paarl Scarce Silver-spotted Copper ♂

Swartland Silver-spotted Copper♂

Brenton Opal ♂

Brenton Opal♂

Tygerberg Monkey Giant Cupid ♂

Mbashe River Large Buff ♀

Geluksburg Giant Cupid ♂

Geluksburg Giant Cupid ♂