Testing the Efficacy of Global Biodiversity Hotspots for Insect Conservation: The Case of South African Katydids

The use of endemism and vascular plants only for biodiversity hotspot delineation has long been contested. Few studies have focused on the efficacy of global biodiversity hotspots for the conservation of insects, an important, abundant, and often ignored component of biodiversity. We aimed to test five alternative diversity measures for hotspot delineation and examine the efficacy of biodiversity hotspots for conserving a non-typical target organism, South African katydids. Using a 1° fishnet grid, we delineated katydid hotspots in two ways: (1) count-based: grid cells in the top 10% of total, endemic, threatened and/or sensitive species richness; vs. (2) score-based: grid cells with a mean value in the top 10% on a scoring system which scored each species on the basis of its IUCN Red List threat status, distribution, mobility and trophic level. We then compared katydid hotspots with each other and with recognized biodiversity hotspots. Grid cells within biodiversity hotspots had significantly higher count-based and score-based diversity than non-hotspot grid cells. There was a significant association between the three types of hotspots. Of the count-based measures, endemic species richness was the best surrogate for the others. However, the score-based measure out-performed all count-based diversity measures. Species richness was the least successful surrogate of all. The strong performance of the score-based method for hotspot prediction emphasizes the importance of including species’ natural history information for conservation decision-making, and is easily adaptable to other organisms. Furthermore, these results add empirical support for the efficacy of biodiversity hotspots in conserving non-target organisms

Tackling an intractable problem: can greater taxon sampling help resolve relationships within the Stenopelmatoidea (Orthoptera: Ensifera)?

The relationships among and within the families that comprise the orthopteran superfamily Stenopelmatoidea (suborder Ensifera) remain poorly understood. We developed a phylogenetic hypothesis based on Bayesian analysis of two nuclear ribosomal and one mitochondrial gene for 118 individuals (84 de novo and 34 from GenBank). These included Gryllacrididae from North, Central, and South America, South Africa and Madagascar, Australia and Papua New Guinea; Stenopelmatidae from North and Central America and South Africa; Anostostomatidae from North and Central America, Papua New Guinea, New Zealand, Australia, and South Africa; members of the Australian endemic Cooloola (three species); and a representative of Lezina from the Middle East. We also included representatives of all other major ensiferan families: Prophalangopsidae, Rhaphidophoridae, Schizodactylidae, Tettigoniidae, Gryllidae, Gryllotalpidae and Myrmecophilidae and representatives of the suborder Caelifera as outgroups. Bayesian analyses of concatenated sequence data supported a clade of Stenopelmatoidea inclusive of all analyzed members of Gryllacrididae, Stenopelmatidae, Anostostomatidae, Lezina and Cooloola. We found Gryllacrididae worldwide to be monophyletic, while we did not recover a monophyletic Stenopelmatidae nor Anostostomatidae. Australian Cooloola clustered in a clade composed of Australian, New Zealand, and some (but not all) North American Anostostomatidae. Lezina was included in a clade of New World Anostostomatidae. Finally, we compiled and compared karyotypes and sound production characteristics for each supported group. Chromosome number, centromere position, drumming, and stridulation differed among some groups, but also show variation within groups. This preliminary trait information may contribute toward future studies of trait evolution. Despite greater taxon sampling within Stenopelmatoidea than previous efforts, some relationships among the families examined continue to remain elusive

Gryllacrididae (Orthoptera: Ensifera) in southern Africa

Although Gryllacrididae are a largely southern hemisphere insect family, they are relatively poorly represented in southern Africa, with three genera (Ametroides Karny, 1928, Glomeremus Karny, 1937, and Stictogryllacris Karny, 1937) and ten species and subspecies recorded from the region. All Ametroides and Glomeremus species are wingless while those of Stictogryllacris are long-winged. All species are arboreal and nocturnal, returning by day to characteristically silk-spun shelters between leaves. Here, we present a diagnosis, key to genera, and high-quality images to assist in identification of Gryllacrididae. By compiling all published information in one place, we hope to facilitate future researchers to investigate this poorly known group

Gryllacrididae (Orthoptera: Ensifera) in southern Africa

Although Gryllacrididae are a largely southern hemisphere insect family, they are relatively poorly represented in southern Africa, with three genera (Ametroides Karny, 1928, Glomeremus Karny, 1937, and Stictogryllacris Karny, 1937) and ten species and subspecies recorded from the region. All Ametroides and Glomeremus species are wingless while those of Stictogryllacris are long-winged. All species are arboreal and nocturnal, returning by day to characteristically silk-spun shelters between leaves. Here, we present a diagnosis, key to genera, and high-quality images to assist in identification of Gryllacrididae. By compiling all published information in one place, we hope to facilitate future researchers to investigate this poorly known group.https://jor.pensoft.netam2019Zoology and Entomolog

Gas exchange patterns and water loss rates in the Table Mountain cockroach, Aptera fusca (Blattodea: Blaberidae)

CITATION: Groenewald, B. et al. 2013. Gas exchange patterns and water loss rates in the Table Mountain cockroach, Aptera fusca (Blattodea: Blaberidae). Journal of Experimental Biology, 216: 3844-3853, doi: 10.1242/jeb.091199.The original publication is available at http://jeb.biologists.orgThe importance of metabolic rate and/or spiracle modulation for saving respiratory water is contentious. One major explanation for gas exchange pattern variation in terrestrial insects is to effect a respiratory water loss (RWL) saving. To test this, we measured the rates of CO2 and H2O release (Embedded Image and Embedded Image, respectively) in a previously unstudied, mesic cockroach, Aptera fusca, and compared gas exchange and water loss parameters among the major gas exchange patterns (continuous, cyclic, discontinuous gas exchange) at a range of temperatures. Mean Embedded Image, Embedded Image and Embedded Image per unit Embedded Image did not differ among the gas exchange patterns at all temperatures (P>0.09). There was no significant association between temperature and gas exchange pattern type (P=0.63). Percentage of RWL (relative to total water loss) was typically low (9.79±1.84%) and did not differ significantly among gas exchange patterns at 15°C (P=0.26). The method of estimation had a large impact on the percentage of RWL, and of the three techniques investigated (traditional, regression and hyperoxic switch), the traditional method generally performed best. In many respects, A. fusca has typical gas exchange for what might be expected from other insects studied to date (e.g. Embedded Image, Embedded Image, RWL and cuticular water loss). However, we found for A. fusca that Embedded Image expressed as a function of metabolic rate was significantly higher than the expected consensus relationship for insects, suggesting it is under considerable pressure to save water. Despite this, we found no consistent evidence supporting the conclusion that transitions in pattern type yield reductions in RWL in this mesic cockroach.http://jeb.biologists.org/content/216/20/3844Publisher's versio

Revealing hidden species distribution with pheromones: the case of Synanthedon vespiformis (Lepidoptera: Sesiidae) in Sweden

Synanthedon vespiformis L. (Lepidoptera: Sesiidae) is considered a rare insect in Sweden, discovered in 1860, with only a few observations recorded until a sex pheromone attractant became available recently. This study details a national survey conducted using pheromones as a sampling method for this species. Through pheromone trapping we captured 439 specimens in Southern Sweden at 77 sites, almost tripling the number of previously reported records for this species. The results suggest that S. vespiformis is truly a rare species with a genuinely scattered distribution, but can be locally abundant. Habitat analyses were conducted in order to test the relationship between habitat quality and the number of individuals caught. In Sweden, S. vespiformis is thought to be associated with oak hosts, but our attempts to predict its occurrence by the abundance of oaks yielded no significant relationships. We therefore suggest that sampling bias and limited knowledge on distribution may have led to the assumption that this species is primarily reliant on oaks in the northern part of its range, whereas it may in fact be polyphagous, similar to S. vespiformis found as an agricultural pest in Central and Southern Europe. We conclude that pheromones can massively enhance sampling potential for this and other rare lepidopteran species. Large-scale pheromone-based surveys provide a snapshot of true presences and absences across a considerable part of a species national distribution range, and thus for the first time provide a viable means of systematically assessing changes in distribution over time with high spatiotemporal resolution

Grasshopper and butterfly local congruency in grassland remnants

Grasshoppers could be considered as appropriate ecological indicators for grasslands owing to their sensitive response to environmental features. However, if grasshoppers are a good ecological indicator, they must (i) also represent other taxa, and (ii) provide additional information over straight measurement of environmental variables. To assess this, we compared the congruence of species richness patterns of grasshoppers with butterflies and environmental variables in two areas with extensive ecological networks (ENs). ENs are landscape-scale remnants of corridors and nodes of natural habitat running throughout a transformed, usually agricultural, landscape. Species richness of grasshoppers and butterflies did not differ among reference and EN sites, but guild composition differed significantly. While ENs adequately conserved overall diversity of these two groups, they were utilized preferentially by small-sized grasshoppers and shrub and tree-feeding butterflies. Reference sites had significantly more graminivorous and intermediate-mobility grasshopper species, as well as more butterfly species with widespread distribution, herbaceous dicot feeders and those with no recorded association to forest edges. Nevertheless, grasshopper and butterfly species richness' were highly correlated. These results were similar across geographic areas, despite the fact that the areas differed significantly in their overall richness and species composition. Although there were some specific significant correlations between environmental variables and diversity, none of the variables could adequately replace use of the insect assemblage for bioindication. We conclude that grasshopper species and guild richness are representative of the butterfly assemblage, and provide information which is not sufficiently clear when utilizing only environmental variables. © 2011 Springer Science+Business Media B.V

Grasshopper bioindicators of effective large-scale ecological networks

Thesis (PhD)--University of Stellenbosch, 2011.ENGLISH ABSTRACT: Land use change is leading to rapid biodiversity loss in terrestrial ecosystems worldwide. Ecological networks (ENs) are systems of remnant natural habitat which remain intact in a transformed matrix, and have been suggested as a means to mitigate the effects of habitat loss and transformation and the resulting loss of biodiversity. Conceptually, ENs are similar to habitat corridors but are larger in scale and more heterogeneous in their design and management. Like corridors, the efficacy of ENs for biodiversity conservation has been called into question and requires empirical investigation. South Africa boasts a unique system of extensive ENs associated with exotic timber plantations, mostly within the highly endangered grassland biome and Indian Ocean Coastal Belt in KwaZulu-Natal Province, South Africa. In these regions, grasshoppers respond sensitively to management practices such as grazing, mowing and burning, justifying their a priori selection as an ecological indicator. In this study, I utilize grasshopper assemblages to determine the efficacy of ENs for biodiversity conservation and suggest guidelines for EN optimization. Specifically, I assess grasshopper assemblage sensitivity and robustness to habitat quality within ENs, congruence of grasshoppers with butterflies, and I identify indicator species which can be utilized by managers for EN assessment in future. I also perform a case study of isolated fragment utilization by a highly mobile generalist species, the bird locust, Ornithacris cyanea (Stoll, 1813) (Acrididae: Cyrtacanthacridinae). Grasshopper assemblages were sampled within ENs in two geographic regions (Zululand and the KwaZulu-Natal Midlands) and in two years (2007 and 2008) during the peak season of grasshopper abundance, late summer (February-April). Local-scale environmental variables relating to management practices and landscape-scale environmental variables relating to design of the ENs were quantified. Management practices explained, on average, two-thirds of the variability in grasshopper assemblages that could be explained, while design variables explained one-third. Grass height and the time since the last fire event were most consistently influential, while area, context, isolation, proportion of bare ground and proportion of forbs at a site, proved influential in some analyses but not others. This response was robust over time and among geographic regions. Grasshopper species richness and abundance were highly congruent with that of butterflies and did not differ among isolated fragments, connected corridors and reference sites, although they did differ among geographic regions. Not all grasshopper species responded similarly to ENs. There was a strong phylogenetic signal in species response to environmental variables, with the distribution of highly mobile families varying more among years. Linear, heavily disturbed power line servitudes had higher grasshopper abundance, and generalist species consistent with early successional assemblages. Reference sites had more graminivorous species and those with intermediate mobility. Three species of grasshopper were identified with IndVal and validated on an independently collected dataset as indicators of high habitat quality. A case study of the bird locust showed that populations of this highly mobile species were effectively isolated and undergoing anthrovicariance even at short distances. These results indicated that heterogeneous ENs supported diverse grasshopper assemblages, although movement among isolated fragments may have been limited. A grasshopper bioindication method for South Africa’s ENs is suggested and has great potential for assessment of a crucial and sensitive trophic layer within the ENs. This method should be field-tested and revised over time as grasshopper relative abundances and species compositions may change. Increased heterogeneity, simulation of multiple successional stages, and increased connectivity are expected to positively impact biodiversity, particularly of insect primary herbivores. Globally, ENs, if managed and designed appropriately, have potential to enhance biodiversity, particularly of smaller resident organisms which can utilize the ENs for movement and live within them.AFRIKAANSE OPSOMMING: Veranderinge in grondgebruik lei tot ‘n vinnige verlies van biodiversiteit in terrestriële ekosysteme wêreldwyd. Ekologiese netwerke (ENs) is sisteme van oorblywende natuurlike habitat wat ongeskonde bly in getransformeerde matrikse, en is voorgestel as ‘n manier om die verlies aan biodiversiteit as gevolg van habitatverlies en transformasie te verminder. Konseptueel, is ENs soortgelyk aan habitat korridors, maar is groter in omvang en meer heterogeen in hulle ontwerp en bestuur. Soos korridors, is die effektiwiteit van ENs om biodiversiteit te bewaar bevraagteken, en vereis dit empiriese ondersoek. Suid-Afrika spog met ‘n unieke stelsel van uitgebreide ENs wat geassossieer is met uitheemse plantasies, meestal in die hoogs bedreigde grasveld bioom en Indiese Oseaan kusstrook in KwaZulu- Natal Provinsie, Suid Afrika. In hierdie streek reageer sprinkane sensitief op bestuurspraktyke soos beweiding, sny en brand. In hierdie studie het ek sprinkaan gemeenskappe gebruik om die effektiwiteit van ENs vir bewaring van biodiversiteit te bepaal en om riglyne te stel vir EN optimering. Spesifiek het ek sprinkaan gemeenskap sensitiwiteit en robustness tot habitat kwaliteit bepaal, oreenstemming tussen sprinkane en skoenlappers getoets, en het ek indikator species geïdentifiseer wat in die toekoms deur bestuurders gebruik kan word vir EN assessering. Ek het ook ‘n gevallestudie gedoen van geïsoleerde fragment benutting deur ‘n hoogs mobiele, algemene spesie, Ornithacris cyanea (Stoll, 1813) (Acrididae: Cyrtacanthacridinae). Sprinkaan gemeenskappe was versamel in twee geografiese gebiede (Zululand en die KwaZulu-Natal Midlands) en in twee jare (2007 en 2008) gedurende die seisoen van hoogste sprinkaan aktiwiteit, laat somer (Februarie – April). Plaaslike-skaal omgewingsveranderlikes met betrekking tot bestuurspraktyke en landskap-skaal omgewingsveranderlikes met betrekking tot die ontwerp van ENs is gekwantifiseer. Bestuurspraktyke verduidelik, gemiddeld, twee derdes van die variasie in die sprinkaan gemeenskappe, terwyl ontwerpveranderlikes een derde verduidelik. Grashoogte en tyd sedert die laaste brand was konsekwent invloedryk, terwyl area, konteks, isolasie, hoeveelheid kaal grond en hoeveelheid kruidagtige plantegroei invloedryk was in sekere analyses, maar in ander nie. Hierdie reaksie was konstant oor tyd en tussen geografiese gebiede. Sprinkaan spesies rykheid en hoeveelheid was hoogs kongruent met die van skoenlappers, en het nie verskil tussen geïsoleerde fragmente, verbinde korridors en verwysingsareas nie, maar hulle het verskil tussen geografiese streke. Nie alle sprinkaan spesies het soortgelyk gereageer tot ENs nie. Daar was ‘n sterk filogenetiese sein in spesies reaksies op die omgewingsveranderlikes, met meer variasie tussen jare in die verspeiding van hoogs mobiele families. Liniêre, hoogs versteurde kraglyn dienspaaie het hoer sprinkaan hoeveelhede gehad en algemene spesies wat geassosieer is met gemeenskappe in vroeë stadiums van suksessie. Verwysingsareas het meer graminivorous spesies gehad en spesies met intermediêre mobiliteit. Drie sprinkaan spesies is geïdentifiseer met IndVal en bevestig met ‘n onafhanklik versamelde dataset as indikators van hoë kwaliteit habitat. ‘n Gevallestudie op O. cyanea het aangedui dat populasies van hierdie hoogs mobiele spesie geïsoleerd is en dat hulle anthrovicariance ondergaan, selfs op kort afstande. Hierdie resultate dui aan dat heterogene ENs diverse sprinkaan gemeenskappe ondersteun, hoewel beweging tussen geïsoleerde fragmente dalk beperk is. Verhoogde heterogeneïteit, simulasie van verskeie suksessiewe fases en meer konnektiwiteit sal moontlik ‘n positiewe invloed op biodiversiteit hê, aangesien sprinkane verteenwoordigend was van insek primêre herbivore. Wêreldwyd, as ENs op ‘n gepaste manier bestuur en ontwerp word, het dit die potensiaal om biodiversiteit te bevorder. Dit is veral belangrik vir kleiner, plaaslike organisms wat ENs kan benut vir beweging en as leefhabitat. ‘n Sprinkaan bioindikasie metode vir Suid-Afrika se ENs is voorgestel en het groot potensiaal vir die assessering van ‘n belangrike en sensitiewe trofiese laag binne die ENs. Hierdie metode moet in die praktyk getoets word en hersien word oor tyd om veranderinge in sprinkaan relatiewe hoeveelhede en spesies komposisies in ag te neem

Notes on southern Africa Jerusalem crickets (Orthoptera: Stenopelmatidae: Sia)

Please help populate SUNScholar with the full text of SU research output. Also - should you need this item urgently, please send us the details and we will try to get hold of the full text as quick possible. E-mail to [email protected]. Thank you.Journal Articles (subsidised)AgriwetenskappeBewaringsekologie en Entomologi

A revision of the South African katydid genus Austrodontura Fontana & Buzzetti (Orthoptera: Tettigoniidae: Phaneropterinae)

The South African genus Austrodontura Fontana & Buzzetti of brachypterous katydids is revised. A. capensis (Walker, 1869) is redescribed and A. castletoni sp. n. from the Eastern Cape Province is described, A. raggei Fontanta & Buzzetti is considered a junior synonym of A. capensis. Acoustic behavior of A. castletoni is described. Copyright © 2011 · Magnolia Press.Articl