Plant richness, turnover, and evolutionary diversity track gradients of stability and ecological opportunity in a megadiversity center.

Research on global patterns of diversity has been dominated by studies seeking explanations for the equator-to-poles decline in richness of most groups of organisms, namely the latitudinal diversity gradient. A problem with this gradient is that it conflates two key explanations, namely biome stability (age and area) and productivity (ecological opportunity). Investigating longitudinal gradients in diversity can overcome this problem. Here we investigate a longitudinal gradient in plant diversity in the megadiverse Cape Floristic Region (CFR). We test predictions of the age and area and ecological opportunity hypotheses using metrics for both taxonomic and phylogenetic diversity and turnover. Our plant dataset includes modeled occurrences for 4,813 species and dated molecular phylogenies for 21 clades endemic to the CFR. Climate and biome stability were quantified over the past 140,000 y for testing the age and area hypothesis, and measures of topographic diversity, rainfall seasonality, and productivity were used to test the ecological opportunity hypothesis. Results from our spatial regression models showed biome stability, rainfall seasonality, and topographic heterogeneity were the strongest predictors of taxonomic diversity. Biome stability alone was the strongest predictor of all diversity metrics, and productivity played only a marginal role. We argue that age and area in conjunction with non-productivity-based measures of ecological opportunity explain the CFR's longitudinal diversity gradient. We suggest that this model may possibly be a general explanation for global diversity patterns, unconstrained as it is by the collinearities underpinning the latitudinal diversity gradient.

Pollinator shifts as triggers of speciation in painted petal irises (Lapeirousia: Iridaceae).

BACKGROUND AND AIMS: Adaptation to different pollinators has been hypothesized as one of the main factors promoting the formation of new species in the Cape region of South Africa. Other researchers favour alternative causes such as shifts in edaphic preferences. Using a phylogenetic framework and taking into consideration the biogeographical scenario explaining the distribution of the group as well as the distribution of pollinators, this study compares pollination strategies with substrate adaptations to develop hypotheses of the primary factors leading to speciation in Lapeirousia (Iridaceae), a genus of corm-bearing geophytes well represented in the Cape and presenting an important diversity of pollination syndromes and edaphic preferences. METHODS: Phylogenetic relationships are reconstructed within Lapeirousia using nuclear and plastid DNA sequence data. State-of-the-art methods in biogeography, divergence time estimation, character optimization and diversification rate assessments are used to examine the evolution of pollination syndromes and substrate shifts in the history of the group. Based on the phylogenetic results, ecological factors are compared for nine sister species pairs in Lapeirousia. KEY RESULTS: Seventeen pollinator shifts and ten changes in substrate types were inferred during the evolution of the genus Lapeirousia. Of the nine species pairs examined, all show divergence in pollination syndromes, while only four pairs present different substrate types. CONCLUSIONS: The available evidence points to a predominant influence of pollinator shifts over substrate types on the speciation process within Lapeirousia, contrary to previous studies that favoured a more important role for edaphic factors in these processes. This work also highlights the importance of biogeographical patterns in the study of pollination syndromes.

Time management and nectar flow: flower handling and suction feeding in long-proboscid flies (Nemestrinidae: Prosoeca).

A well-developed suction pump in the head represents an important adaptation for nectar-feeding insects, such as Hymenoptera, Lepidoptera and Diptera. This pumping organ creates a pressure gradient along the proboscis, which is responsible for nectar uptake. The extremely elongated proboscis of the genus Prosoeca (Nemestrinidae) evolved as an adaptation to feeding from long, tubular flowers. According to the functional constraint hypothesis, nectar uptake through a disproportionately elongated, straw-like proboscis increases flower handling time and consequently lowers the energy intake rate. Due to the conspicuous length variation of the proboscis of Prosoeca, individuals with longer proboscides are hypothesised to have longer handling times. To test this hypothesis, we used field video analyses of flower-visiting behaviour, detailed examinations of the suction pump morphology and correlations of proboscis length with body length and suction pump dimensions. Using a biomechanical framework described for nectar-feeding Lepidoptera in relation to proboscis length and suction pump musculature, we describe and contrast the system in long-proboscid flies. Flies with longer proboscides spent significantly more time drinking from flowers. In addition, proboscis length and body length showed a positive allometric relationship. Furthermore, adaptations of the suction pump included an allometric relationship between proboscis length and suction pump muscle volume and a combination of two pumping organs. Overall, the study gives detailed insight into the adaptations required for long-proboscid nectar feeding, and comparisons with other nectar-sucking insects allow further considerations of the evolution of the suction pump in insects with sucking mouthparts.

A cockroach that jumps.

We report on a newly discovered cockroach (Saltoblattella montistabularis) from South Africa, which jumps and therefore differs from all other extant cockroaches that have a scuttling locomotion. In its natural shrubland habitat, jumping and hopping accounted for 71 per cent of locomotory activity. Jumps are powered by rapid and synchronous extension of the hind legs that are twice the length of the other legs and make up 10 per cent of the body weight. In high-speed images of the best jumps the body was accelerated in 10 ms to a take-off velocity of 2.1 m s(-1) so that the cockroach experienced the equivalent of 23 times gravity while leaping a forward distance of 48 times its body length. Such jumps required 38 µJ of energy, a power output of 3.4 mW and exerted a ground reaction force through both hind legs of 4 mN. The large hind legs have grooved femora into which the tibiae engage fully in advance of a jump, and have resilin, an elastic protein, at the femoro-tibial joint. The extensor tibiae muscles contracted for 224 ms before the hind legs moved, indicating that energy must be stored and then released suddenly in a catapult action to propel a jump. Overall, the jumping mechanisms and anatomical features show remarkable convergence with those of grasshoppers with whom they share their habitat and which they rival in jumping performance.

The first species of Nemestrinidae (Diptera) endemic to Madagascar: A remarkable new species of Atriadops Wandolleck, 1897.

A new species of Nemestrinidae, Atriadops irwini Barraclough sp. nov., is described and illustrated from Sakaramy in the far north of Madagascar at about the same latitude as the Comoros Islands. The species was collected in lowland tropical forest by Dr Michael Irwin. Atriadops Wandolleck, 1897, is a small genus of Nemestrinidae in the subfamily Trichopisideinae. Six named species are distributed across the Australasian, Oriental, Afrotropical and Neotropical Regions. Atriadops irwini sp. nov. is thus only the seventh species in the genus (the first new species described in almost 70 years) and the second valid species from the Afrotropical Region. This is the first record of Atriadops from Madagascar, where the new species is the only endemic nemestrinid. Nycterimyia capensis Bezzi is the only other nemestrinid recorded from Madagascar, but it also occurs in South Africa (where it was first described) and Kenya. The world fauna of Atriadops is discussed and all known larval host records are listed.

Review of the genus Amblymelanoplia Dombrow, 2002 (Coleoptera: Scarabaeidae: Melolonthinae: Hopliini) with the description of ninety-three new species from South Africa and observations on its biogeography and phylogeny.

Twenty years after establishing the genus Amblymelanoplia Dombrow, 2002 a large amount of new material collected has warranted a critical review of the established species and a revision of the genus. From this process, we describe 93 new species from the Northern Cape, Western Cape, Mpumalanga and Limpopo Provinces of the Republic of South Africa. A lectotype is designated for Gouna burchelli Arrow, 1917 which is transferred to Amblymelanoplia. The new species are: A. aequabilis Dombrow, new species, A. albolineata Dombrow, new species, A. albosquamosa Dombrow, new species, A. alluaudi Dombrow, new species, A. aquifolia Dombrow, new species, A. arrowi Dombrow, new species, A. atritica Dombrow, new species, A. baehri Dombrow, new species, A. balkei Dombrow, new species, A. bicostata Dombrow, new species, A. bidentata Dombrow, new species, A. bimucronata Dombrow, new species, A. brancuccii Dombrow, new species, A. braunsi Dombrow, new species, A. brinckmanni Dombrow, new species, A. burmeisteri Dombrow, new species, A. caliginosa Dombrow, new species, A. carinata Dombrow, new species, A. castanea Dombrow, new species, A. cederbergensis Dombrow, new species, A. citrusdalensis Dombrow, new species, A. constricta Dombrow, new species, A. costata Dombrow, new species, A. crenata Dombrow, new species, A. deyrollei Dombrow, new species, A. dregei Dombrow, new species, A. drumonti Dombrow, new species, A. elkeae Dombrow, new species, A. enodisuturalis Dombrow, new species, A. fabricii Dombrow, new species, A. felschei Dombrow, new species, A. frischi Dombrow, new species, A. fryi Dombrow, new species, A. fusca Dombrow, new species, A. gifbergensis Dombrow, new species, A. glenlyonensis Dombrow, new species, A. goodhopensis Dombrow, new species, A. gydoensis Dombrow, new species, A. jekeli Dombrow, new species, A. klassi Dombrow, new species, A. kraatzi Dombrow, new species, A. kulzeri Dombrow, new species, A. laingsburgensis Dombrow, new species, A. lichtensteini Dombrow, new species, A. lajoyei Dombrow, new species, A. macrodentata Dombrow, new species, A. mamreensis Dombrow, new species, A. mcleodi Dombrow, new species, A. microdentata Dombrow, new species, A. montana Dombrow, new species, A. mortoni Dombrow, new species, A. multidentata Dombrow, new species, A. murrayi Dombrow, new species, A. nigra Dombrow, new species, A. obscura Dombrow, new species, A. paraunidentata Dombrow, new species, A. pascoei Dombrow, new species, A. pentheri Dombrow, new species, A. pseudocostata Dombrow, new species, A. pseudostrigata Dombrow, new species, A. pseudounidentata Dombrow, new species, A. pulchra Dombrow, new species, A. pulleiacea Dombrow, new species, A. punctata Dombrow, new species, A. pygidialis Dombrow, new species, A. reichei Dombrow, new species, A. robertsi Dombrow, new species, A. sainvali Dombrow, new species, A. scheini Dombrow, new species, A. scutellaris Dombrow, new species, A. selbi Dombrow, new species, A. septentrionalestris Dombrow, new species, A. setosa Dombrow, new species, A. soetwaterensis Dombrow, new species, A. sprecherae Dombrow, new species, A. squamosa Dombrow, new species, A. stalsi Dombrow, new species, A. stellenboschensis Dombrow, new species, A. strigata Dombrow, new species, A. sulcata Dombrow, new species, A. swartbergensis Dombrow, new species, A. swellendamensis Dombrow, new species, A. thomsoni Dombrow, new species, A. tradouwensis Dombrow, new species, A. tuberculata Dombrow, new species, A. turneri Dombrow, new species, A. unidentata Dombrow, new species, A. vansoni Dombrow, new species, A. webbi Dombrow, new species, A. wittmeri Dombrow, new species, A. worcesterensis Dombrow, new species, A. zuercherae Dombrow, new species and A. zumpti Dombrow, new species. Three cryptic species complexes within the species A. burchelli (Arrow, 1917) [+6], A. cornuta Dombrow, 2002 [+10] and A. capensis Dombrow, 2002 [+14] were detected. A revised key of the genus and observations about its biogeography and phylogeny are given. Important details of the morphological characters of the body and the parameres of the species are illustrated and their distributions are mapped. We also provide habitat information.

Hidden Diversity-A New Speciose Gall Midge Genus (Diptera: Cecidomyiidae) Associated with Succulent Aizoaceae in South Africa.

Aizoaceae (Caryophyllales) constitute one of the major floral components of the unique Greater Cape Floristic Region (GCFR), with more than 1700 species and 70% endemism. Within succulent Aizoaceae, the subfamily Ruschioideae is the most speciose and rapidly diversifying clade, offering potential niches for the diversification of specialized herbivorous insects. Nevertheless, insect diversity on these plants has not been studied to date, and knowledge of gall-inducing insects in the Afrotropics is generally scarce. Our recent observations indicate that succulent Aizoaceae in the GCFR support a rich and largely unstudied community of gall midges (Diptera: Cecidomyiidae). Here, we provide a first report of their diversity with a description of a new genus, Ruschiola Dorchin, and ten new species, based on morphological and molecular analyses of material collected during a three-year targeted survey across major GCFR vegetation types. A high degree of morphological uniformity in Ruschiola suggests recent diversification and necessitated the use of molecular data and laboratory rearing from host plants to verify species boundaries and host ranges.

Allometric relationships shape foreleg evolution of long-legged oil bees (Melittidae: Rediviva).

Exaggerated traits of pollinators have fascinated biologists for centuries. To understand their evolution, and their role in coevolutionary relationships, an essential first step is to understand how traits scale allometrically with body size, which may reveal underlying developmental constraints. Few pollination studies have examined how traits can adaptively diverge despite allometric constraints. Here, we present a comparative study of narrow-sense static and evolutionary allometry on foreleg length and body size of oil-collecting bees. Concurrently, we assess the relationship between scaling parameters and spur lengths of oil-secreting host flowers. Across species and populations, we found low variation in static slopes (nearly all <1), possibly related to stabilizing selection, but the static intercept varied substantially generating an evolutionary allometry steeper than static allometry. Variation in static intercepts was explained by changes in body size (∼28% species; ∼68% populations) and spur length (remaining variance: ∼36% species; ∼94% populations). The intercept-spur length relationship on the arithmetic scale was positive but forelegs did not track spur length perfectly in a one-to-one relationship. Overall, our study provides new insights on how phenotypic evolution in the forelegs of oil-collecting bees is related to the variability of the allometric intercept and adaptation to host plants.

Nectar Uptake of a Long-Proboscid Prosoeca Fly (Nemestrinidae)-Proboscis Morphology and Flower Shape.

Several Prosoeca (Nemestinidae) species use a greatly elongated proboscis to drink nectar from long-tubed flowers. We studied morphological adaptations for nectar uptake of Prosoecamarinusi that were endemic to the Northern Cape of South Africa. Our study site was a small isolated area of semi-natural habitat, where the long-tubed flowers of Babiana vanzijliae (Iridaceae) were the only nectar source of P. marinusi, and these flies were the only insects with matching proboscis. On average, the proboscis measured 32.63 ± 2.93 mm in length and less than 0.5 mm in diameter. The short labella at the tip are equipped with pseudotracheae that open at the apical margin, indicating that nectar is extracted out of the floral tube with closed labella. To quantify the available nectar resources, measurements of the nectar volume were taken before the flies were active and after observed flower visits. On average, an individual fly took up approximately 1 µL of nectar per flower visit. The measured nectar quantities and the flower geometry allowed estimations of the nectar heights and predictions of necessary proboscis lengths to access nectar in a range of flower tube lengths.

Sexual deception of a beetle pollinator through floral mimicry.

Sexual mimicry is a complex multimodal strategy used by some plants to lure insects to flowers for pollination.1-4 It is notable for being highly species-specific and is typically mediated by volatiles belonging to a restricted set of chemical compound classes.3,4 Well-documented cases involve exploitation of bees and wasps (Hymenoptera)5,6 and flies (Diptera).7-9 Although beetles (Coleoptera) are the largest insect order and are well known as pollinators of both early and modern plants,10,11 it has been unclear whether they are sexually deceived by plants during flower visits.12,13 Here we report the discovery of an unambiguous case of sexual deception of a beetle: male longhorn beetles (Chorothyse hessei, Cerambycidae) pollinate the elaborate insectiform flowers of a rare southern African orchid (Disa forficaria), while exhibiting copulatory behavior including biting the antennae-like petals, curving the abdomen into the hairy lip cleft, and ejaculating sperm. The beetles are strongly attracted by (16S,9Z)-16-ethyl hexadec-9-enolide, a novel macrolide that we isolated from the floral scent. Structure-activity studies14,15 confirmed that chirality and other aspects of the structural geometry of the macrolide are critical for the attraction of the male beetles. These results demonstrate a new biological function for plant macrolides and confirm that beetles can be exploited through sexual deception to serve as pollinators.

Review of the genus Beckhoplia Dombrow, 2005 with the description of fifteen new species from South Africa and observations on its biogeography (Coleoptera: Scarabaeidae: Melolonthinae: Hopliini).

Fifteen years after establishing the genus Beckhoplia Dombrow, 2005 a large amount of new material collected has warranted a critical review of the established species and a revision of the genus. From this process, we describe fifteen new species from the Northern Cape Province and Western Cape Province of the Republic of South Africa: Beckhoplia bicolor Dombrow, new species, B. caliginosa Dombrow, new species, B. castanea Dombrow, new species, B. dolichiocnemis Dombrow, new species, B. elkeae Dombrow, new species, B. fusca Dombrow, new species, B. gifbergensis Dombrow, new species, B. nigra Dombrow, new species, B. nigrofasciata Dombrow, new species, B. nigrosetosa Dombrow, new species, B. pallidibrunnea Dombrow, new species, B. pulchra Dombrow, new species, B. pumilla Dombrow, new species, B. setosa Dombrow, new species and B. suturalis Dombrow, new species. Two cryptic species complexes within the species B. colvillei Dombrow, 2005 and B. occidentalis Dombrow, 2005 were detected. A revised key of the genus and observations about its biogeography are given. Important details of the morphological characters of the body and the parameres of the species are illustrated and their distributions are mapped. We also provide habitat and host plant information.

The allometry of proboscis length in Melittidae (Hymenoptera: Apoidae) and an estimate of their foraging distance using museum collections.

An appreciation of body size allometry is central for understanding insect pollination ecology. A recent model utilises allometric coefficients for five of the seven extant bee families (Apoidea: Anthophila) to include crucial but difficult-to-measure traits, such as proboscis length, in ecological and evolutionary studies. Melittidae were not included although they are important pollinators in South Africa where they comprise an especially rich and morphologically diverse fauna. We measured intertegular distance (correlated with body size) and proboscis length of 179 specimens of 11 species from three genera of Melittidae. With the inclusion of Melittidae, we tested the between family differences in the allometric scaling coefficients. AIC model selection was used to establish which factors provide the best estimate of proboscis length. We explored a hypothesis that has been proposed in the literature, but which has not been tested, whereby body and range sizes of bees are correlated with rainfall regions. We tested this by using body size measurements of 2109 museum specimens from 56 species of Melittidae and applied the model coefficients to estimate proboscis length and foraging distance. Our results from testing differences across bee families show that with the addition of Melittidae, we retained the overall pattern of significant differences in the scaling coefficient among Apoidea, with our model explaining 98% of the variance in species-level means for proboscis length. When testing the relationship between body size and rainfall region we found no relationship for South African Melittidae. Overall, this study has added allometric scaling coefficients for an important bee family and shown the applicability of using these coefficients when linked with museum specimens to test ecological hypothesis.

Feeding ecology and sexual dimorphism in a speciose flower beetle clade (Hopliini: Scarabaeidae).

The relationship between feeding ecology and sexual dimorphism is examined in a speciose South African monkey beetle clade. We test whether feeding and mating at a fixed site (embedding guild) is associated with greater levels of sexual dimorphism and possibly sexual selection than species using unpredictable feeding resources (non-embedding guild). Sexual dimorphism was measured using a point scoring system for hind leg and colour across the two feeding guilds for >50% of the regional fauna. Quantification of hind leg dimorphism using a scoring system and allometric scaling were used to identify traits subject to sexual selection. Feeding guild had a significant effect on hind leg dimorphism, with embedders having high and non-embedders low scores. The sessile and defendable distribution of females on stable platform flowers may favour contests and associated hind leg weaponry. In contrast, degree of colour dimorphism between the sexes was not associated with any particular feeding guild, and may serve to reduce male conflict and combat. Embedder males had high proportions (∼76%) of species with positive allometric slopes for almost all hind leg traits. For male non-embedders, only ∼37% of species showed positive scaling relationships. Phylogenetic data, in conjunction with behavioural data on the function of leg weaponry and visual signalling among males is needed to better understand the link between sexual dimorphism and sexual selection in the radiation of the monkey beetles.

Assessing the role of dispersed floral resources for managed bees in providing supporting ecosystem services for crop pollination.

Most pollination ecosystem services studies have focussed on wild pollinators and their dependence on natural floral resources adjacent to crop fields. However, managed pollinators depend on a mixture of floral resources that are spatially separated from the crop field. Here, we consider the supporting role these resources play as an ecosystem services provider to quantify the use and availability of floral resources, and to estimate their relative contribution to support pollination services of managed honeybees. Beekeepers supplying pollination services to the Western Cape deciduous fruit industry were interviewed to obtain information on their use of floral resources. For 120 apiary sites, we also analysed floral resources within a two km radius of each site based on geographic data. The relative availability of floral resources at sites was compared to regional availability. The relative contribution of floral resources-types to sustain managed honeybees was estimated. Beekeepers showed a strong preference for eucalypts and canola. Beekeepers selectively placed more hives at sites with eucalypt and canola and less with natural vegetation. However, at the landscape-scale, eucalypt was the least available resource, whereas natural vegetation was most common. Based on analysis of apiary sites, we estimated that 700,818 ha of natural vegetation, 73,910 ha of canola fields, and 10,485 ha of eucalypt are used to support the managed honeybee industry in the Western Cape. Whereas the Cape managed honeybee system uses a bee native to the region, alien plant species appear disproportionately important among the floral resources being exploited. We suggest that an integrated approach, including evidence from interview and landscape data, and fine-scale biological data is needed to study floral resources supporting managed honeybees.

A striking new species of Prosoeca Schiner, 1867 (Diptera: Nemestrinidae): An important pollinator from the Bokkeveld Plateau, Northern Cape Province, South Africa.

For more than 20 years an undescribed species of Prosoeca has been referred to in numerous publications by pollination biologists, evolutionary biologists and ecologists, originally as being part of the Prosoeca peringueyi Lichtwardt, 1920, pollination guild. Ongoing research in these and related fields has necessitated the formal description of this large-bodied, striking new species, with a proboscis 1.5-2.3 x body length (mean proboscis length ± SD 36.25 ± 3.90 mm). Prosoeca marinusi Barraclough sp. nov. is described from a long series from the Hantam National Botanical Garden, Nieuwoudtville, Bokkeveld Plateau, Northern Cape Province, South Africa. The species is a narrow-range endemic and is restricted to the Nieuwoudtville area. Observations on the biology of the species are also presented. Prosoeca marinusi Barraclough sp. nov. is the only or main pollinator of at least four plant species (all regional endemics) in the family Iridaceae that flower from August to September. During August, Lapeirousia oreogena Goldblatt and Babiana vanzyliae L. Bolus are the main host flowers, while later in the spring season, Babiana framesii L. Bolus is most abundant in the Nieuwoudtville area.

Counting complete? Finalising the plant inventory of a global biodiversity hotspot.

The Cape Floristic Region-the world's smallest and third richest botanical hotspot-has benefited from sustained levels of taxonomic effort and exploration for almost three centuries, but how close is this to resulting in a near-complete plant species inventory? We analyse a core component of this flora over a 250-year period for trends in taxonomic effort and species discovery linked to ecological and conservation attributes. We show that >40% of the current total of species was described within the first 100 years of exploration, followed by a continued steady rate of description. We propose that <1% of the flora is still to be described. We document a relatively constant cohort of taxonomists, working over 250 years at what we interpret to be their 'taxonomic maximum.' Rates of description of new species were independent of plant growth-form but narrow-range taxa have constituted a significantly greater proportion of species discoveries since 1950. This suggests that the fraction of undiscovered species predominantly comprises localised endemics that are thus of high conservation concern. Our analysis provides important real-world insights for other hotspots in the context of global strategic plans for biodiversity in informing considerations of the likely effort required in attaining set targets of comprehensive plant inventories. In a time of unprecedented biodiversity loss, we argue for a focused research agenda across disciplines to increase the rate of species descriptions in global biodiversity hotspots.

Comparative morphology of the mouthparts of the megadiverse South African monkey beetles (Scarabaeidae: Hopliini): feeding adaptations and guild structure.

Although anthophilous Coleoptera are regarded to be unspecialised flower-visiting insects, monkey beetles (Scarabaeidae: Hopliini) represent one of the most important groups of pollinating insects in South Africa's floristic hotspot of the Greater Cape Region. South African monkey beetles are known to feed on floral tissue; however, some species seem to specialise on pollen and/or nectar. The present study examined the mouthpart morphology and gut content of various hopliine species to draw conclusions on their feeding preferences. According to the specialisations of their mouthparts, the investigated species were classified into different feeding groups. Adaptations to pollen-feeding included a well-developed, toothed molar and a lobe-like, setose lacinia mobilis on the mandible as well as curled hairs or sclerotized teeth on the galea of the maxillae. Furthermore, elongated mouthparts were interpreted as adaptations for nectar feeding. Floral- and folial-tissue feeding species showed sclerotized teeth on the maxilla, but the lacinia was mostly found to be reduced to a sclerotized ledge. While species could clearly be identified as floral or folial tissue feeding, several species showed intermediate traits suggesting both pollen and nectar feeding adaptations. Mismatches found between mouthpart morphology and previously reported flower visiting behaviours across different genera and species requires alternative explanations, not necessarily associated with feeding preferences. Although detailed examinations of the mouthparts allowed conclusions about the feeding preference and flower-visiting behaviour, additional morphological and behavioural investigations, combined with greater taxon sampling and phylogenetic data, are still necessary to fully understand hopliine host plant relationships, related to monkey beetle diversity.

Optimising Regionalisation Techniques: Identifying Centres of Endemism in the Extraordinarily Endemic-Rich Cape Floristic Region.

We used a very large dataset (>40% of all species) from the endemic-rich Cape Floristic Region (CFR) to explore the impact of different weighting techniques, coefficients to calculate similarity among the cells, and clustering approaches on biogeographical regionalisation. The results were used to revise the biogeographical subdivision of the CFR. We show that weighted data (down-weighting widespread species), similarity calculated using Kulczinsky's second measure, and clustering using UPGMA resulted in the optimal classification. This maximized the number of endemic species, the number of centres recognized, and operational geographic units assigned to centres of endemism (CoEs). We developed a dendrogram branch order cut-off (BOC) method to locate the optimal cut-off points on the dendrogram to define candidate clusters. Kulczinsky's second measure dendrograms were combined using consensus, identifying areas of conflict which could be due to biotic element overlap or transitional areas. Post-clustering GIS manipulation substantially enhanced the endemic composition and geographic size of candidate CoEs. Although there was broad spatial congruence with previous phytogeographic studies, our techniques allowed for the recovery of additional phytogeographic detail not previously described for the CFR.

Roles of Spatial Scale and Rarity on the Relationship between Butterfly Species Richness and Human Density in South Africa.

Wildlife and humans tend to prefer the same productive environments, yet high human densities often lead to reduced biodiversity. Species richness is often positively correlated with human population density at broad scales, but this correlation could also be caused by unequal sampling effort leading to higher species tallies in areas of dense human activity. We examined the relationships between butterfly species richness and human population density at five spatial resolutions ranging from 2' to 60' across South Africa. We used atlas-type data and spatial interpolation techniques aimed at reducing the effect of unequal spatial sampling. Our results confirm the general positive correlation between total species richness and human population density. Contrary to our expectations, the strength of this positive correlation did not weaken at finer spatial resolutions. The patterns observed using total species richness were driven mostly by common species. The richness of threatened and restricted range species was not correlated to human population density. None of the correlations we examined were particularly strong, with much unexplained variance remaining, suggesting that the overlap between butterflies and humans is not strong compared to other factors not accounted for in our analyses. Special consideration needs to be made regarding conservation goals and variables used when investigating the overlap between species and humans for biodiversity conservation.

Delivery of crop pollination services is an insufficient argument for wild pollinator conservation.

There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation. However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost-effective way. Here we show that, while the contribution of wild bees to crop production is significant, service delivery is restricted to a limited subset of all known bee species. Across crops, years and biogeographical regions, crop-visiting wild bee communities are dominated by a small number of common species, and threatened species are rarely observed on crops. Dominant crop pollinators persist under agricultural expansion and many are easily enhanced by simple conservation measures, suggesting that cost-effective management strategies to promote crop pollination should target a different set of species than management strategies to promote threatened bees. Conserving the biological diversity of bees therefore requires more than just ecosystem-service-based arguments.