Benjamin W. Price

Patterns and processes underlying evolutionary significant units in the Platypleura stridula L. species complex (Hemiptera: Cicadidae) in the Cape Floristic Region, South Africa

Cicadas have been shown to be useful organisms for examining the effects of distribution, plant association and geographical barriers on gene flow between populations. The cicadas of the Platypleura stridula species complex are restricted to the biologically diverse Cape Floristic Region (CFR) of South Africa. They are thus an excellent study group for elucidating the mechanisms by which hemipteran diversity is generated and maintained in the CFR. Phylogeographical analysis of this species complex using mitochondrial DNA Cytochrome Oxidase I (COI) and ribosomal 16S sequence data, coupled with preliminary morphological and acoustic data, resolves six clades, each of which has specific host‐plant associations and distinct geographical ranges. The phylogeographical structure implies simultaneous or near‐simultaneous radiation events, coupled with shifts in host‐plant associations. When calibrated using published COI and 16S substitution rates typical for related insects, these lineages date back to the late Pliocene – early Pleistocene, coincident with vegetation change, altered drainage patterns and accelerated erosion in response to neotectonic crustal uplift and cyclic Pleistocene climate change, and glaciation‐associated changes in climate and sea level.

Thermal ecophysiology of seven carrion‐feeding blowflies in Southern Africa

A variety of temperature thresholds for larvae, pupae, and adults of seven African species of carrion‐feeding blowflies (Diptera: Calliphoridae) was measured and compared to understand their basic thermal biology and the influence of temperature on their behaviour. Calliphora croceipalpis (Jaennicke) had consistently lower temperature thresholds than all other species tested for all larval (42.9 °C), pupal (16.6 °C), and adult (45.6 °C) stages. Larvae (50.1 °C) and adults (53.4 °C) of Chrysomya marginalis (Robineau‐Desvoidy) had higher upper lethal temperature thresholds than all other species and weighed more than all other species. Pupae and adults of both Chrysomya albiceps (Wiedemann) and Lucilia sericata (Meigen) had similar temperature thresholds, whereas Chrysomya putoria (Wiedemann), Chrysomya chloropyga (Wiedemann), and Chrysomya megacephala (Fabricius) had inconsistent rank temperature thresholds between the larval, pupal, and adult stages. With a few minor exceptions, the nervous activity, muscle activity, and death thresholds in female adult flies responded at higher temperatures than conspecific male flies for all species tested. Similarly, female adult flies weighed consistently more than conspecific male flies for all species tested, except Ca. croceipalpis. These data suggest that there is a phylogenetic component to the thermal biology of blowflies, because Ca. croceipalpis belongs to a primarily Holarctic genus and shows adaptation to that climate even though it inhabits Africa. Comparisons between these temperature thresholds and the distributions of blowfly species present on three rhinoceros carcasses suggest that blowfly larvae with high upper lethal temperature thresholds (particularly C. marginalis) dominate in interspecific competition on the carcass by raising the temperature of the amassed maggots above the thresholds of other carrion‐feeding blowflies, through metabolically generated heat.

Cryptic variation in an ecological indicator organism: mitochondrial and nuclear DNA sequence data confirm distinct lineages of Baetis harrisoni Barnard (Ephemeroptera: Baetidae) in southern Africa

BackgroundBaetis harrisoni Barnard is a mayfly frequently encountered in river studies across Africa, but the external morphological features used for identifying nymphs have been observed to vary subtly between different geographic locations. It has been associated with a wide range of ecological conditions, including pH extremes of pH 2.9–10.0 in polluted waters. We present a molecular study of the genetic variation within B. harrisoni across 21 rivers in its distribution range in southern Africa.ResultsFour gene regions were examined, two mitochondrial (cytochrome c oxidase subunit I [COI] and small subunit ribosomal 16S rDNA [16S]) and two nuclear (elongation factor 1 alpha [EF1α] and phosphoenolpyruvate carboxykinase [PEPCK]). Bayesian and parsimony approaches to phylogeny reconstruction resulted in five well-supported major lineages, which were confirmed using a general mixed Yule-coalescent (GMYC) model. Results from the EF1α gene were significantly incongruent with both mitochondrial and nuclear (PEPCK) results, possibly due to incomplete lineage sorting of the EF1α gene. Mean between-clade distance estimated using the COI and PEPCK data was found to be an order of magnitude greater than the within-clade distance and comparable to that previously reported for other recognised Baetis species. Analysis of the Isolation by Distance (IBD) between all samples showed a small but significant effect of IBD. Within each lineage the contribution of IBD was minimal. Tentative dating analyses using an uncorrelated log-normal relaxed clock and two published estimates of COI mutation rates suggest that diversification within the group occurred throughout the Pliocene and mid-Miocene (~2.4–11.5 mya).ConclusionsThe distinct lineages of B. harrisoni correspond to categorical environmental variation, with two lineages comprising samples from streams that flow through acidic Table Mountain Sandstone and three lineages with samples from neutral-to-alkaline streams found within eastern South Africa, Malawi and Zambia. The results of this study suggest that B. harrisoni as it is currently recognised is not a single species with a wide geographic range and pH-tolerance, but may comprise up to five species under the phylogenetic species concept, each with limited pH-tolerances, and that the B. harrisoni species group is thus in need of taxonomic review.

A watershed study on genetic diversity: Phylogenetic analysis of the Platypleura plumosa (Hemiptera: Cicadidae) complex reveals catchment-specific lineages

Historical biogeography studies have at their disposal a small suite of vicariance models to explain genetic differentiation within and between species. One of these processes involves the role of river catchments and their associated watersheds, in driving diversification and is applicable to both aquatic and terrestrial organisms. Although the idea of catchments structuring the genetic history of aquatic organisms is reasonably well understood, their effect on terrestrial organisms has largely been overlooked, with relevant studies being limited in scope. South Africa presents a perfect test-bed for elucidating this mechanism of diversification due to its rich biodiversity, range of climatic environments and many large river catchments. Here we use the cicadas of the Platypleura plumosa complex to highlight the importance of catchments and their associated watersheds in driving diversification of terrestrial invertebrates that lack an aquatic life-stage. Population structure was found to correspond to primary and in some cases secondary catchments; highlighting the need to include information on catchment structure when formulating hypotheses of population diversification. Recognizing that climate change in the near future is likely to alter the environment, and particularly precipitation patterns, insight into recent patterns of population change related to catchments may be useful in a conservation context.

The shifting landscape of genes since the Pliocene: terrestrial phylogeography in the Greater Cape Floristic Region

The Greater Cape Floristic Region (GCFR) is considered megadiverse, and is recognized primarily for its extraordinary floristic richness and endemism (Chapter 4). Despite the deep origins of many clades in the Cenozoic (e.g. Chapter 5, Tolley et al. 2006; Forest, Grenyer, et al. 2007; Fjeldså and Bowie 2008), much of the present-day diversity within the GCFR is attributed to diversification during the Pliocene (5–2.5 Ma) and Pleistocene (2.5 Ma–20 000). This diversity is observable through the substantial phylogeographic structuring in many taxa examined to date, particularly for those that are specialists and/or lack vagility (e.g. Price et al. 2007; Smit et al. 2007; Price et al. 2010; Willows-Munro and Matthee 2011). However, because diversification on this timescale is relatively recent, the result is characteristically shallow genetic lineages, often within recently radiated species or species complexes (e.g. Mummenhoff et al. 2005; Tolley et al. 2006, 2009). Our understanding regarding patterns of floristic diversity in the GCFR have benefited greatly from molecular phylogenetic work, particularly for deeply divergent clades rooted in the Cenozoic (Chapter 5), with comparatively less work at the phylogeographic level. In contrast, a great deal of phylogeographic work has been produced on animal taxa. This floral– faunal imbalance probably reflects a bias due to the broad availability of suitable genetic markers for resolving phylogeographic patterns in animals. In particular, the mitochondrial genome (mtDNA) has been successfully utilized across multiple animal taxa, despite the inherent bias of this marker due to its uniparental inheritance mode. The general focus on understanding the evolution of species-rich clades of plants (i.e. ‘Cape clades’; Linder 2003), and their use as proxies to unravel the causal factors responsible for the floral diversity of the GCFR, might also explain the limited number of phylogeographic studies for plant groups. Typically, there are two time frames to which phylogeographic structure is attributed in the GCFR. The earlier diversification events are rooted in the Late Miocene and Pliocene, and these are often associated with recently diverged species, which are usually reciprocally monophyletic, but exhibit shallow divergences (e.g. Tolley et al. 2006; Price et al. 2010; Pereira-da-Conceicoa et al. 2012). More recent diversification events are dated to the Pleistocene, but these appear to be either divergence events amongst populations within species (Smit et al. 2010) or in some cases between species that are not reciprocally monophyletic and share ancestral polymorphisms in the mtDNA (Tolley et al. 2006; Oatley et al. 2012). Often, discrete geographic boundaries amongst these clades are blurred, with alleles or haplotypes overlapping across geographic regions or habitat types (Swart et al. 2009; Russo et al. 2010). The lack of clear geographic pattern in the distribution of haplotypes could be due to shared ancestral polymorphisms in what are presently species (or populations) with restricted gene flow.

Inselect: Automating the Digitization of Natural History Collections

The world’s natural history collections constitute an enormous evidence base for scientific research on the natural world. To facilitate these studies and improve access to collections, many organisations are embarking on major programmes of digitization. This requires automated approaches to mass-digitization that support rapid imaging of specimens and associated data capture, in order to process the tens of millions of specimens common to most natural history collections. In this paper we present Inselect—a modular, easy-to-use, cross-platform suite of open-source software tools that supports the semi-automated processing of specimen images generated by natural history digitization programmes. The software is made up of a Windows, Mac OS X, and Linux desktop application, together with command-line tools that are designed for unattended operation on batches of images. Blending image visualisation algorithms that automatically recognise specimens together with workflows to support post-processing tasks such as barcode reading, label transcription and metadata capture, Inselect fills a critical gap to increase the rate of specimen digitization.

A review of the alderfly genus Leptosialis Esben-Petersen (Megaloptera, Sialidae) with description of a new species from South Africa.

Abstract The monotypic South African alderfly genus Leptosialis Esben-Petersen, 1920 is reviewed and Leptosialis africana Esben-Petersen, 1920 is redescribed. In the process a new species of alderfly Leptosialis necopinata sp. n. from the Eastern Cape and KwaZulu-Natal provinces of South Africa is recognised and described. Within Sialidae the new species most closely resembles Leptosialis africana. A key to the two species of Leptosialis using both adult and larval characters is provided.

Systematic revision reveals underestimated diversity of the South African endemic fishfly genus Taeniochauliodes Esben‐Petersen (Megaloptera: Corydalidae)

Taeniochauliodes is the most common and widely distributed fishfly genus in South Africa, with one historically recognized valid species Taeniochauliodes ochraceopennis Esben‐Petersen. The present systematic revision of Taeniochauliodes has found that this genus consists of at least eight species: T. angustus sp.n., T. attenuatus sp.n., T. barnardi sp.n., T. fuscus sp.n., T. minutus sp.n., and T. natalensis sp.n. Description of all new species and a redescription of T. esbenpeterseni comb.n. & stat.rev. and T. ochraceopennis are made. These species all have relatively narrowly confined distributions. An interspecific phylogeny of Taeniochauliodes is estimated based on adult morphological data. The historical biogeography of this genus is discussed based on the phylogenetic results and the present distribution of each species, suggesting that the origin of Taeniochauliodes likely dates back to the Late Cretaceous. The earliest branch, which separates T. natalensis sp.n. from the remaining South African species, suggests an early vicariance event occurred between KwaZulu‐Natal and more western parts of South Africa. Furthermore, speciation within Taeniochauliodes is hypothesized to be correlated with fragmentation of its forest habitat during the Plio‐Pleistocene.

NightLife: A cheap, robust, LED based light trap for collecting aquatic insects in remote areas

Inland waters cover less than 1% of our planets surface, yet provide habitat to approximately one hundred thousand aquatic insect species, i.e. those with at least one aquatic lifestage (Balian et al. 2008, Dijkstra et al. 2014). Considering the taxonomic deficit in these groups this figure is likely a significant underestimate of the true aquatic insect diversity (Dijkstra et al. 2014). The majority of aquatic insect diversity is comprised of true flies (Diptera), followed by caddisflies (Trichoptera), beetles (Coleoptera), dragonflies (Odonata), stoneflies (Plecoptera) and mayflies (Ephemeroptera) (Balian et al. 2008, Dijkstra et al. 2014). The ecology of these groups has been the focus of significant study due to their role as bioindicators of water quality, as many species are sensitive to pollution and sudden changes in their environment (Rosenberg and Resh 1993). In addition many aquatic dipteran species are vectors of disease (e.g. Currie and Adler 2008, Rueda 2008). Aquatic insects are surveyed using a variety of methods including light trapping (e.g. Collier et al. 1997) which attracts emergent adults, and often mayfly subadults, using mercury vapour (MV) bulbs or actinic fluorescent tubes. Light trapping can be either active: attended light sheets, or passive: a combination of a light with a trap (Hardwick 1968, Hienton 1974). Passive traps allow samples from multiple sites to be collected in parallel by an individual in the field, with the number of sampling sites limited by the size and weight of each trap. Current Lights Mercury vapour (MV) bulbs work by passing an arc of electric current through ionised mercury vapour; as a result these bulbs require a relatively high current to maintain the arc and thus are limited to use with either mains power or a petrol / diesel powered generator. Remote areas therefore cannot be sampled without significant effort. In addition MV bulbs are excessively bright for attracting aquatic insects, and tend to draw large numbers of night flying lepidoptera and other non-target species. MV bulbs are also delicate, easily damaged in transport and liable to break if exposed to rain during operation due to thermal fracture of the glass, and their high operating temperature is a waste of power. Actinic fluorescent tubes also use mercury, but their method of operation requires a smaller current draw. While an improvement over MV bulbs, the current draw of fluorescent tubes does still require sizeable batteries if they are to be used in remote locations. For example a single 4W flourescent tube requires a 6v 12Ah battery weighing up to 2kg for an approximate 12hr run time. Fluorescent tubes are also delicate and liable to damage under field conditions. Both MV bulbs and actinic fluorescent tubes contain mercury, which if released in the field can be hazardous for the environment. An ideal aquatic insect light trap would have these properties: Be able to run from small, standard, [potentially] rechargeable batteries. Use low power light sources, at frequencies targeted for insect vision. Be robust enough for field use without special packing or travel arrangements. Be capable of autonomous operation. Light Emitting Diodes Light Emitting Diodes (LEDs) are semiconductor devices that are used in a wide range of scientific, home and commercial lighting solutions due to the following properties: low power / high-efficiency (compared to incandescent / fluorescent) narrow spectral emissions (i.e. specific colours) long-life low-operating temperature durable (enclosed in a solid epoxy case rather than hollow glass) small size and weight These same properties also lend themselves to the use of LEDs in insect collection.

Revision of the Megaloptera (Insecta: Neuropterida) of Madagascar

The Megaloptera fauna of Madagascar comprise two endemic genera: Haplosialis Navás, 1927 (Sialidae) and Madachauliodes Paulian, 1951 (Corydalidae: Chauliodinae). Here the two genera are revised, with detailed descriptions and illustrations. A new species, Madachauliodes bicuspidatus Liu, Price & Hayashi, sp. nov., is described. Furthermore the phylogeny and biogeography of the Madagascan fauna is discussed.