Phylogenetic analyses reveal multiple new stem-boring Tetramesa taxa (Hymenoptera: Eurytomidae): implications for the biological control of invasive African grasses

Many native South African grass species have become invasive elsewhere in the world. The application of biological control to invasive grasses has been approached with trepidation in the past, primarily due to concerns of a perceived lack of host specific herbivores. This has changed in recent times, and grasses are now considered suitable candidates. The Tetramesa Walker genus (Hymenoptera: Eurytomidae) has been found to contain species that are largely host specific to a particular grass species, or complex of closely related congeners. Very little taxonomic work exists for Tetramesa in the southern hemisphere, and the lack of morphological variability between many Tetramesa species has made identification difficult. This limits the ability to assess the genus for potential biological control agents. Species delimitation analyses indicated 16 putative novel southern African Tetramesa taxa. Ten of these were putative Tetramesa associated with Eragrostis curvula (Schrad.) Nees and Sporobolus pyramidalis Beauv. and S. natalensis Steud., which are alien invasive weeds in Australia. Of these ten Tetramesa taxa, eight were only found on a single host plant, while two taxa were associated with multiple species in a single grass genus. The Tetramesa spp. on S. pyramidalis and S. africanus were deemed suitably host-specific to be used as biological control agents. Field host range data for the Tetramesa species on E. curvula revealed that the wasp may not be suitably host specific for use as a biological control agent. However, further host specificity testing on non-target native Australian species is required

Sample size assessments for thermal physiology studies: An R package and R Shiny application

Required sample sizes for a study need to be carefully assessed to account for logistics, cost, ethics and statistical rigour. For example, many studies have shown that methodological variations can impact the critical thermal limits (CTLs) recorded for a species, although studies on the impact of sample size on these measures are lacking. Here, we present ThermalSampleR; an R CRAN package and Shiny application that can assist researchers in determining when adequate sample sizes have been reached for their data. The method is particularly useful because it is not taxon specific. The Shiny application offers a user‐friendly interface equivalent to the package for users not familiar with R programming. ThermalSampleR is accompanied by an in‐built example dataset, which we use to guide the user through the workflow with a fully worked tutorial.Funder: National Research Foundation; doi: http://dx.doi.org/10.13039/501100001321 Funder: South African Research Chairs Initiative of the Department of Science and Technology Funder: Working for Water (WfW) programme of the Department of Environmental Affairs: Natural Resource Management programme (DEA: NRM

Sample size assessments for thermal physiology studies: An R package and R Shiny application

Required sample sizes for a study need to be carefully assessed to account for logistics, cost, ethics and statistical rigour. For example, many studies have shown that methodological variations can impact the critical thermal limits (CTLs) recorded for a species, although studies on the impact of sample size on these measures are lacking. Here, we present ThermalSampleR; an R CRAN package and Shiny application that can assist researchers in determining when adequate sample sizes have been reached for their data. The method is particularly useful because it is not taxon specific. The Shiny application offers a user‐friendly interface equivalent to the package for users not familiar with R programming. ThermalSampleR is accompanied by an in‐built example dataset, which we use to guide the user through the workflow with a fully worked tutorial

Historical diversification of Pseudonympha Wallengren, 1857 (Lepidoptera: Nymphalidae: Satyrinae).

The butterfly genus Pseudonympha and several related genera are endemic to southern Africa. Although many of the species are montane, some inhabit the arid interior of South Africa, offering an opportunity to study the palaeobiogeography of this biome. Morphological data (for all species of Pseudonympha and allied African and Asian genera) and molecular data (WG and COI genes for nine of the 15 species of Pseudonympha and all of the southern African endemic genera of Ypthimina) were compiled. Phylogenetic analysis indicated that Pseudonympha apparently originated in the Cape Fold Mountains about 15 Mya ago and spread steadily eastwards and northwards along the Great Escarpment during the aridification of the region, perhaps assisted by orogeny in the east and oceanic cooling in the west. Aridification cycles seem to have intermittently isolated some early lineages in elevated habitats in the interior, so that those lineages show lower speciation rates (or perhaps higher extinction rates) than those in the east. Four species delineation techniques indicated that some species are taxonomically oversplit. Based on genetic polyphyly and morphological similarity, we propose that the status of P. swanepoeli be reduced to that of a subspecies of P. varii, such that all the north-eastern populations from Harrismith to Tzaneen fall under P. varii swanepoeli van Son stat. n., and all the southern populations fall under P. varii varii van Son stat. n. Ultimately, the diversification of both of these lineages seems tied to their host plants’ response to aridification brought on by continental drift and orogeny. Sympatric organisms (eg cicadas) with biologies focused around different resources (eg savanna trees) show other patterns of diversification. The phylogenetic analysis of the subtribe Ypthimina also supports the monophyly of Paternympha, paraphyly of Ypthima, recognition of Thymipa Moore stat. rev. as a phylogenetic independent genus, and new relationships for Strabena

Addressing the red flags in cochineal identification: The use of molecular techniques to identify cochineal insects that are used as biological control agents for invasive alien cacti

Invasive Cactaceae cause considerable damage to ecosystem function and agricultural practices around the world. The most successful biological control agents used to combat this group of weeds belong to the genus Dactylopius (Hemiptera: Dactylopiidae), commonly known as ‘cochineal’. Effective control relies on selecting the correct species, or in some cases, the most effective intraspecific lineage, of cochineal for the target cactus species. Many of the Dactylopius species are so morphologically similar, and in the case of intraspecific lineages, identical, that numerous misidentifications have been made in the past. These errors have resulted in failed attempts at the biological control of some cactus species. This study aimed to generate a multi-locus genetic database to enable the accurate identification of dactylopiids. Genetic characterization was achieved through the nucleotide sequencing of three gene regions (12S rRNA, 18S rRNA, and COI) and two inter-simple sequence repeats (ISSR). Nucleotide sequences were very effective for species-level and D. tomentosus lineage-level identification, but could not distinguish between the two lineages within D. opuntiae commonly used for biological control of various Opuntia spp. Fragment analysis through the use of ISSRs successfully addressed this issue. This is the first time that a method has been developed that can distinguish between these two D. opuntiae lineages. Using the methods developed in this study, biological control practitioners can ensure that the most effective agent species and lineages are used for each cactus target weed, thus maximizing the level of control

Sample size assessments for thermal physiology studies: An R package and R Shiny <scp>application</scp>

From Crossref journal articles via Jisc Publications RouterHistory: received 2023-03-10, accepted 2023-07-28, epub 2023-08-17, issued 2023-08-17, published 2023-08-17Article version: VoRPublication status: PublishedFunder: National Research Foundation; FundRef: https://doi.org/10.13039/10.13039/501100001321AbstractRequired sample sizes for a study need to be carefully assessed to account for logistics, cost, ethics and statistical rigour. For example, many studies have shown that methodological variations can impact the critical thermal limits (CTLs) recorded for a species, although studies on the impact of sample size on these measures are lacking. Here, we present ThermalSampleR; an R CRAN package and Shiny application that can assist researchers in determining when adequate sample sizes have been reached for their data. The method is particularly useful because it is not taxon specific. The Shiny application offers a user‐friendly interface equivalent to the package for users not familiar with R programming. ThermalSampleR is accompanied by an in‐built example dataset, which we use to guide the user through the workflow with a fully worked tutorial