Lacewings at Little England, Beaufort West

Nesoleon boschimanus. Photo credit: Les Underhill (2018)

Report by Les Underhill

Lacewings are not one of the charismatic groups of insects, and have been poorly studied. They consume aphids and do pollination, so they are one of the key ecosystem service providers, and deserve better attention than what they have received to date. There is only one entomologist in South Africa who has focused on lacewings, Dr Mervyn Mansell, at the University of Pretoria. He says that, in South Africa, there are currently 415 described species in 14 families of lacewings. There are many taxa that await description, and he reckons that we should eventually end up with about 500–550 species for South Africa. For the whole of Africa, it is likely that there will prove to be 1000–1500 species.

On three trips to the Landmark Foundation’s farm at Little England in the Karoo north of Beaufort West a total of 18 lacewing have been photographed and uploaded to the LacewingMAP section of the Virtual Museum (http://vmus.adu.org.za). 13 have been identified to species level, three to genus and, for one, the photo was only good enough for the ID to be done to family. The number of species so far is a paltry six! But it is a start. These are the first ever records for this grid cell.

Mervyn Mansell, who does the identifications for LacewingMAP, reckons that we could expect at least 50 species in that area. “It is actually an extremely rich area for lacewings. Lots of fieldwork needs to be done here.”

The first six species for this grid cell are listed below. The species notes were written by Mervyn Mansell in his comments on the identification. The number of records to date is given, as well as the link to the record in LacewingMAP with what is currently the best available photo of the species in the grid cell. The distribution map for each species, based on the LacewingMAP database, is also provided. The take home message from these maps is plain: Our knowledge of the distributions of the lacewings is weak.

Systematic list of lacewings recorded on the farm Little England

Centroclisis maligna. Photo credit: Les Underhill (2018)

Centroclisis maligna (Myrmeleontidae)

This species is fairly common and widespread in the drier western parts of southern Africa. It is readily distinguished form other Centroclisis species by its reddish colour. The large robust three-toothed larvae live freely in sand and do not construct pitfall traps.

One record: http://vmus.adu.org.za/?vm=LacewingMAP-10704

–000–

Creoleon mortifer. Photo credit: Les Underhill (2018)

Creoleon mortifer (Myrmeleontidae)

A common and widespread species, occurring throughout most of southern Africa and northward. It is highly variable, often with black streaks in the wings that have led to numerous synonyms. Rests with wings wrapped around the body. Larvae live freely in sand.

Two records: http://vmus.adu.org.za/?vm=LacewingMAP-10758

–000–

Myrmeleon doralice. Photo credit: Les Underhill (2018)

Myrmeleon doralice (Myrmeleontidae)

This species is common and widespread throughout southern Africa, particularly in the drier areas. Larvae construct pits and are pinkish in colour. Although the adults are fairly common, the larvae are not frequently encountered, although they are pit builders, and usually occur in open exposed situations.

Three records: http://vmus.adu.org.za/?vm=LacewingMAP-10706 m

–000–

Nannoleon michaelseni. Photo credit: Les Underhill (2018)

Nannoleon michaelseni (Myrmeleontidae)

This species is widespread in South Africa and Namibia, and is fairly common in the drier western parts of the subregion. It is currently the only species in the genus, although another undescribed species is also known. It is characterized by the broad clear wings and long clavate antennae. Nothing is known of its biology.

Two records: http://vmus.adu.org.za/?vm=LacewingMAP-10701

–000–

Nesoleon boschimanus. Photo credit: Les Underhill (2018)

Nesoleon boschimanus (Myrmeleontidae)

This species is widespread in South Africa and Namibia, and is fairly common in the drier western parts of the subregion. It is currently the only species in the genus, although another undescribed species is also known. It is characterized by the broad clear wings and long clavate antennae. Nothing is known of its biology.

Three records: http://vmus.adu.org.za/?vm=LacewingMAP-10705

–000–

Dichochrysa tacta. Photo credit: Les Underhill (2018)

Dichochrysa tacta (Chrysopidae)

Another of the “brown” “green lacewings”. Fairly widespread and common in the drier western parts of South Africa. Not known from neighbouring countries. Larvae live freely on vegetation, where they are active predators.

Two records: http://vmus.adu.org.za/?vm=LacewingMAP-10784

–000–

We are grateful to the Landmark Foundation for their warm hospitality at Little England. Mervyn Mansell’s role in doing the identifications and writing the comments is crucial to the success of this project.

The data were extracted from the LacewingMAP section of the Virtual Museum (Animal Demography Unit (2018). LacewingMAP Virtual Museum. Accessed at http://vmus.adu.org.za/?vm=LacewingMAP on 2018-04-02)

 

Bird ringing report – Paardeberg 2018/03/28

Cape robin-chat (Cossypha caffra). Photo credit: Dieter Oschadleus (2018)

Cape robin-chat – Virtual Museum record

Report by Dieter Oschadleus

The Paardeberg stands out as a mountainous island in an agricultural landscape between Paarl/Wellington and Malmesbury in the Swartland region of the Western Cape. Very little bird ringing has taken place here, so Les Underhill and I had a ringing session on Bowwood Farm on Wednesday.

The top species was Cape White-eye (n=22), followed by Southern Masked Weavers (n=8), where 2 of the latter were males in partial breeding plumage. The ring of one bird has been recovered in the Paardeberg area, a Cape Weaver ringed with ring 231054 in Tygerberg.

Thanks to Julian and Bridget Johnsen for hosting us!

Streaky-headed seedeater (Serinus gularis). Photo credit: Dieter Oschadleus (2018)

Streaky-headed seedeater – Virtual Museum record

Karoo prinia (Prinia maculosa). Photo credit: Dieter Oschadleus (2018)

Karoo prinia – Virtual Museum record

Cape weaver (Ploceus capensis). Photo credit: Dieter Oschadleus (2018)

Cape weaver – Virtual Museum record

Southern masked-weaver (Ploceus velatus). Photo credit: Dieter Oschadleus (2018)

Southern masked-weaver – Virtual Museum record

Olive thrush (Turdus olivaceus). Photo credit: Dieter Oschadleus (2018)

Olive thrush – Virtual Museum record

Cape white-eye (Zosterops virens). Photo credit: Dieter Oschadleus (2018)

Cape white-eye – Virtual Museum record

BDIgest Friday, 30 March 2018

In this week’s digest of research that caught our attention, we look at socio-economic and development issues associated with background climate oscillations and anthropogenic-driven climate change. We also look at climate change mitigation and biodiversity conservation, artificial selection pressures on a large carnivore, and methods of estimating population density in an elusive carnivore species.

 

1

Bet the farm – rolling the climate dice

Food security around the world is closely linked to climate variability, but in a recent article in Nature Communications we learn just how extensive the problem is. Crop productivity on two-thirds of the world’s cropland is significantly affected by three climate oscillations: El Niño Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD) and the North Atlantic Oscillation (NAO). The areas affected by the three oscillations are inhabited by approximately 4 billion people and contribute two-thirds of global food crop calorie production.

DOI: 10.1038/s41467-017-02071-5

Ed: Against this background, the implications of adding variability and unpredictability of anthropogenic-driven climate change would suggest that risk in crop farming and food security will only increase for half the world’s population.

 

 

2

Photo credit: CDC Global 2012 (CC BY 2.0)

The carbon sins of the rich shall be visited upon the poor

The world’s population is becoming increasingly urban, and recent rapid urbanisation has resulted in a proliferation of informal urban settlements or slums, which are home to > 800 million people. Some of this urban migration may be due to food security risk associated with climate variability (such as described in the article above). A compelling article in Ecological Indicators provides an important example of the social science required for assessing climate change vulnerability in these at-risk urban communities. In the particular slum community studied, overall vulnerability to climate change was high, there was a high information barrier (and hence low awareness of climate change impacts). As might be expected, for coping strategies, financial and food support were deemed important, followed by information support.

DOI: 10.1016/j.ecolind.2018.03.031

Ed: Interestingly, technological support was deemed least important for coping with climate change in slum communities, yet much attention is focused on technological interventions and relatively little attention is given to practical information and resource distribution.

 

 

3

Photo credit: Bobulix 2010 (CC BY-NC-ND 2.0)

Picking winners and losers – conserving carbon or biodiversity

Although the net impact of climate change is likely to be negative for biodiversity, there will be some taxonomic groups that benefit from climate change. Carbon conservation – specifically, conserving above-ground carbon stocks in tropical forests – is seen as one of the ways to combat climate change. Contrary to the putative net effects of climate change, it is tacitly assumed that this form of carbon conservation will promote biodiversity. A thought-provoking article in Science Advances suggests that the relationship between above-ground carbon stocks and biodiversity differs for different taxonomic groups, and may also differ in re-growth forests compared to old growth forests (within a taxonomic group). Thus, among the taxonomic groups studied, the relationship between carbon stocks and biodiversity could vary from positive to negative and could appear linear or non-linear. Choosing a single climate change mitigation strategy, such as conserving tropical forests to maximise carbon stocks, will inherently include trade-offs in biodiversity in certain taxonomic groups. A similar article in Science Advances from 2017 about using fire suppression in savannas to maximise carbon sequestration came to similar conclusions. Thus, more nuanced, integrated approaches that consider both carbon conservation and biodiversity conservation (across multiple taxonomic groups) may be required as we try to mitigate anthropogenic-driven climate change.

DOI: 10.1126/sciadv.aar6603

Ed: This is going to be a tricky concept to grapple with. Climate change in general is leading to population declines, geographic range shifts (and expansions or contractions). When biodiversity is already a climate change concern, how will we weigh the biodiversity benefits of mitigating climate change against the potential biodiversity costs (in some taxa) of maximising carbon conservation? As a species, we will need to become much better at assessing risks, attributing value, and optimising trade-offs.

 

 

4

Photo credit: Karlafg 2010 (CC-BY-SA-3.0)

Survival of the … slowest?

Typically, in harvested populations, the selection pressure of hunting or harvest should select for accelerated life history traits. However, research on a hunted population of brown bears in Sweden, published this week in Nature Communications, shows that when hunting regulations prevent the harvest of mothers with cubs, selection pressure may favour slower life history traits. Mothers that exhibit longer maternal care receive a survival benefit. Interestingly, this survival benefit cancels out the loss of reproductive opportunities associated with the slower breeding strategy, such that net fitness for the slower breeding females is similar to that of females following a “normal” maternal care strategy. Over the last 30 years, the proportion of litters in the population raised over 2.5 years has increased measurably relative to the proportion of litters raised over 1.5 years.

DOI: 10.1038/s41467-018-03506-3

Ed: A great demonstration of artificial selection at work … and over a relatively short time-frame for a long-lived large mammal.

 

 

5

Photo credit: Lukas Kaffer 2007 (CC-BY-SA-3.0)
Leopards are contagious too,
Be careful tiny tots,
They don’t give you a temperature
But lots and lots of spots
(Spike Milligan)

Spotty spotting of the spotted

A major issue in biodiversity research revolves around how to count animals in a population or estimate their population density reliably. This is particularly problematic for “cryptic” species that have low detection probabilities. Solitary felids often fit into this category, including leopards (Panthera pardus), which are largely nocturnal and have coat patterns that provide good camouflage. In a great study reported in the African Journal of Ecology, leopard density was estimated across a broad geographic region in South Africa (the Eastern Cape Province and Western Cape Province). The authors used movement data of collared animals and “captures” from remotely-triggered cameras to estimate density using two different techniques – which provided surprisingly similar final density estimates. These density estimates of approximately 1 leopard per 100 sq km are low compared to published estimates for populations elsewhere in the leopard’s geographic range (published, for example, here). Even within this region, density estimates varied greatly among sites (from 0.24 to 1.89 leopards per 100 sq km).

DOI: 10.1111/aje.12512

Ed: This study produced great congruence between two different methods of estimating leopard density, suggesting that the reported densities for the region are quite reliable. The study also opens up interesting questions about what drives variability in leopard population density (both within this geographic region, and across the leopard’s geographic range).

 

 

 

 

 

I can’t believe it’s not butter!

This week’s conservation art profile:

Malachite Kingfisher (oil painting … not a photo!) by Tanya Scott.

Tanya has recently completed an MSc at the University of Cape Town using the data from the bird atlas project in South Africa (Birds along a transect across KwaZulu-Natal: altitudinal preference and altitudinal migration). She represented South Africa in the half-marathon at the 29th Summer Universiade in Taipei City in 2017. Her last formal art education was at Westerford High School in Cape Town where the art teacher was Mr Anthony Cain.

 

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