Arthropods are crucial to ecosystems, yet face multiple threats, with recent studies indicating global declines and many species at risk of extinction. The primary threats include land use change, climate change, invasive species, pesticides, pollution, and overexploitation, all of which can interact to compound this vulnerability. Although most insect conservation research comes from the Global North, South Africa has a long history of insect (and other arthropod) conservation, including comprehensive IUCN Red List assessments. We systematically assessed South African insect conservation in the peer reviewed literature (2000–2024) to identify research patterns, gaps, and implementation priorities. The Grasslands and Fynbos biomes are the most sampled, with the Succulent Karoo the least. Most work focused on beetles, dragonflies, butterflies, ants, grasshoppers, and spiders. Few studies provide publicly available data (<2%) or indicate where reference collections were housed (31%). The main threats identified in South Africa are habitat loss and fragmentation through agriculture, pesticides, timber plantations, and invasive species. Most studies highlighted solutions, including greening of urban and agricultural landscapes, reduced pesticide use, and establishing conservation corridors. Research output has increased fourfold between 2000–2004 and 2020–2024, but the lack of long-term monitoring and data accessibility challenges means we cannot confidently assess population trends across most of South Africa’s insect diversity. South Africa’s extensive conservation entomology research should inform policy changes and public education. South Africa has demonstrated the capacity for large-scale insect conservation, yet we need to build on these achievements by establishing monitoring networks which are essential for sustaining ecological function and human well-being.
Drosophila suzukii (spotted-wing drosophila) is an invasive pest causing significant economic losses in soft-skinned fruit crops globally. This study presents comprehensive temperature-dependent life table data and phenology models for an African D. suzukii population collected in Kenya. Developmental time, mortality, fecundity, and adult longevity were assessed under constant temperatures from 12 to 30 °C. Using Insect Life Cycle Modelling (ILCYM) software, linear and nonlinear models were applied to characterise the effects of temperature on life history traits. Additionally, spatial risk indices including Establishment Risk Index (ERI), Generation Index (GI), and Activity Index (AI) were mapped globally for current and future (2061–2080) climate scenarios. The models revealed developmental thresholds of 6.87–34.05 °C (egg-larva) and 9.13–31.97 °C (pupa), with optimal development and reproduction occurring between 20–27 °C. Mortality rates increased at thermal extremes, with minimal mortality near 19.9 °C. Peak intrinsic rate of natural increase (rm = 0.276 day-¹) and finite rate of increase (λ = 1.317) were observed at 27 °C, while population growth declined sharply above 30 °C. Mapped spatial risk indices indicate a largely unchanged pattern between current and future projections, with high risk areas in tropical regions and localised changes in intensity and also distribution. These findings are consistent with other studies which have also indicated that temperature-driven phenology influences the spatial risk patterns of most insects. Given the recent invasion and ongoing spread of D. suzukii in Africa, integrating empirical data with mechanistic modelling provides a robust framework to anticipate invasion risk and optimise surveillance and control under changing climatic conditions.
Cryptophlebia peltastica (Meyrick) (1921) (Lepidoptera: Tortricidae) is an agricultural and economically important pest of litchis and macadamias in South Africa. Non-chemical based control options for C. peltastica are required to reduce the economic importance of the pest. Understanding the biology of C. peltastica and effectively rearing this pest in the laboratory will facilitate the search for alternative control options. We adapted the Thaumatotibia leucotreta rearing protocol to successfully rear C. peltastica in the laboratory for the first time, allowing us to determine aspects of its biology. Females oviposited an average of 180.58 eggs per day, with a maximum of 506 eggs oviposited over their lifespan. Egg viability was 90.56 %. Five larval instars were determined using head capsule width measurement. The biology of C. peltastica was similar to that of T. leucotreta, also in the Grapholitini tribe of tortricids. This study is the first to report successful laboratory rearing and biological parameters of C. peltastica, the results of which have already proven to be useful in the discovery of a novel virus, which has been developed into a biopesticide and development of a postharvest cold disinfestation treatment.
The tomato leaf miner Phthorimaea (Tuta) absoluta (Meyrick) (Lepidoptera: Gelechiidae) is an important invasive pest native to South America that causes damage to solanaceous crops in many parts of the world. Under laboratory conditions, the predatory capacity of Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) was assessed on P. absoluta life stages. All N. tenuis life stages preferred eggs, 1st to 3rd instar larvae of P. absoluta over 4th instar and pupa. In addition, adult N. tenuis fed voraciously on eggs (4.78 +/- 0.33 within 48h) and the 1stinstar (4.12 +/- 0.28 within 48h) of P. absoluta. Seven prey densities ranging from 5 to 110 eggs per leaf and 1st instar larva per individual petri dishes were exposed to adult female and the 5th nymphal stage of the predator for a functional response study. Adult and 5th nymphal N. tenuis females showed type III functional predatory response to varying densities of P. absoluta. The attack rate of adult female preying on 1st instar larva was the highest (0.025 h-1). The highest handling time was recorded for the 5th nymphal stage that fed on 1st instar larva (0.030 h). Life stage-specific application of N. tenuis should be advocated to improve the biological control of P. absoluta. In tomato-based agroecosystems in Ghana, mature females and late nymphs of N. tenuis should be released during peak egg laying periods and early larval stages of the pest. Predation on vulnerable stages will increase thereby decreasing insect numbers before the larvae mine into the plant and are shielded by plant tissue. To sustainably manage P. absoluta in Ghana, pheromone monitoring, botanical insecticides and cultural practices should be used along with biological control using N. tenuis and other compatible biocontrol agents.
The rapid and accurate identification of invasive pest insects at quarantine stations or ports of entry is crucial for preventing their establishment and spread in new territories. Here, we present an effective and rapid genetic identification technique utilising loop-mediated isothermal amplification (LAMP) to detect the presence of the peach fruit fly, Bactrocera zonata. The LAMP assay was designed to target the cytochrome oxidase subunit I (COI) gene region of B. zonata, ensuring high specificity and sensitivity, and to discriminate it from a range of other economically important Bactrocera species. By utilising isothermal conditions, LAMP eliminates the need for lengthy thermal cycling and enables rapid amplification of target DNA within a short period. Additionally, a rapid DNA extraction method combined with the use of an intercalating UV fluorescent dye allows for fast and reliable interpretation of results without the need for specialised equipment. Validation studies were conducted using known samples of B. zonata, as well as other Bactrocera species commonly encountered in quarantine settings including B. dorsalis, B. correcta, B. tryoni, B. oleae, B. cucurbitae and B. tau. The power of this LAMP assay lies in its specificity to accurately distinguish B. zonata from other closely related Bactrocera species. Moreover, the assay exhibits a remarkably short turnaround time, with results obtained in under an hour, facilitating timely decision-making at quarantine stations.
Inter-cultivar pollination is essential for high-quality blueberry production, as it increases both fruit set and fruit size. In commercial orchards, this is often achieved by alternating blueberry cultivars across rows, based on the assumption that honey bees move pollen between cultivars byswitching rows. However, honey bee movement patterns in orchards remain understudied, and it is unclear whether this design effectively supports intercultivar pollination. To address this knowledge gap in a South African context, we determined the frequency of honey bee foraging movements across versus along blueberry rows. While observing a focal foraging honey bee, we recorded the number of flowers visited on a blueberry bush, whether the bee transitioned between plants, and whether these transitions occurred along or across a row. Our observations revealed that honey bees predominantly foraged along rows (over 90% of transitions), rarely switching across rows. Consequently, alternating cultivars by row is likely to limit inter-cultivar pollination in South African blueberry orchards, potentially reducing yield. We recommend interplanting compatible cultivars within rows to enhance pollen transfer and fruit production. Given that honey bees are used globally as the primary managed pollinator, similar movement patterns may occur in other regions, suggesting that modifying planting designs could increase yields of blueberries and other bee-pollinated crops with minimal additional cost. However, these findings are based on observations from a single commercial orchard and should be replicated across multiple farms and environmental conditions to determine the generality of these patterns.
Ants represent a crucial component of terrestrial ecosystems owing to their roles in nutrient cycling, soil aeration and predation. However, myrmecological studies are relatively rare in the Afrotropics, including Rwanda. This study reveals high ant diversity within Akagera National Park in eastern Rwanda, an ecologically rich area comprising savannas, woodlands and wetlands. A nonsystematic sampling scheme was used across different habitats within the park, implementing various sampling techniques, namely pitfall traps, leaf litter sifting, Winkler leaf litter extraction, vegetation sweeping and hand collection from rocks, rotten wood and dead trees. The findings indicate a high diversity of ant species, with six subfamilies comprising 41 genera including 119 named species and 68 morphospecies. A minimum of 17 of these morphospecies represent undescribed species. Of the collected species, 149 were recorded for the first time in Rwanda. These findings highlight the status of Akagera National Park as a biodiversity hotspot. They also provide a baseline inventory for future entomological, ecological and conservation efforts in Akagera National Park. We recommend additional studies to formally describe the morphospecies currently confirmed as undescribed and to further investigate the status of the remaining unidentified morphospecies.
The false codling moth (FCM, Thaumatotibia leucotreta Meyrick) is a major constraint on chilli pepper production and export in Ghana. Although chemical pesticides remain the main control strategy, their effectiveness is limited and export restrictions on synthetic residues highlight the need for sustainable alternatives. To address this challenge, the virulence of seven native Metarhizium isolates (UGKAP1, UGJKCS9, UGJKCS10, UGNAKC1, UGAFMF20, UGAFMF8 and UGSUHC1) obtained from agricultural fields in Ghana against final instar FCMs at 1 & times; 10(8) conidia/mL was evaluated via conidial-sand assays, and compared with that of two USDA ARSEF isolates (Beauveria bassiana ARSEF 252 and Metarhizium anisopliae sensu lato ARSEF 4570). As abiotic environmental factors can affect fungal efficacy, the influence of humidity on the infectivity of four selected isolates (UGJKCS9, UGJKCS10, UGSUHC1 and UGAFMF20) was assessed. All seven native isolates caused > 80% pupal mortality within 21 days. The pupal mortality rates of ARSEF 252 and ARSEF 4570 were 49% and 57%, respectively. The most virulent isolate, UGJKCS9, exhibited an LC50 of 2.7 & times; 10(6) conidia/mL and an LT50 of 3 days. High pupal mortality (82-100% at 10(5) and 10(7) conidia/mL) occurred across all tested humidity levels (43%, 75% and 98% RH) for all four isolates. These results indicate that the tested isolates, particularly UGJKCS9, exhibit strong potential as sustainable alternative control agents for FCMs in Ghana, warranting further evaluation under field conditions for integration into chilli pepper pest management programmes.
Long-proboscid flies of the genera Moegistorhynchus and Prosoeca (Nemestrinidae) are charismatic nectar-feeding insects with several species considered to be keystone pollinators, yet their conservation status is unknown. Recent taxonomic work has improved our understanding of some species identities and distributions, therefore providing a basis for conservation assessments. Building on this updated taxonomy, we conducted baseline IUCN Red List assessments for eight endemic species to evaluate their extinction risk. We estimated range-size metrics following IUCN guidelines and incorporated national spatial overlays to assess habitat loss, ecosystem threat status, and protected area coverage. We found that two species are classified as Endangered, one as Near Threatened, three as Data Deficient and two as Least Concern. All species assessed have experienced high habitat loss (28-57%) as a result of agriculture and urban expansion, particularly along coastal areas, and 8-31% of the remaining habitat falls within threatened ecosystems. Less than 11% of the ranges of the Endangered and Near Threatened species overlap with protected areas. Data Deficient species are known from fewer than three localities, underscoring the need for systematic surveys and intensive sampling of these poorly known taxa. Information on distributions, population sizes, host plants, and larval biology remains extremely limited for all taxa and is urgently needed. As thefirst Red List assessmentforflies in South Africa, and for a specialist fly pollinator, this study identifies threatened species, highlights data-deficient taxa, and provides important baseline information for future research and conservation efforts on this hyper-diverse insect group.
This study investigated the effect of nutrition on development of wings and adult body condition of Bactrocera dorsalis (Hendel), an exotic pest of Asian origin and a species of economic importance in South Africa. Six host fruit types were used to rear B. dorsalis: mango, guava, orange, grapefruit, papaya and apple. One day after emergence, adults were used for tethered flight assessments using computerised flight mills. Additional flies were assessed in terms of wing morphology using geometric morphometrics, flight muscle mass, and lipid content. There were significant differences in the larval and pupal developmental time as well as larval and pupal survival amongst the tested host fruit, with orange tending to lead to poor performance in development and survival. Host fruit type and sex had a significant effect on the flight performance and wing morphology of B. dorsalis. There was a significant difference between female and male wing shapes, indicating the presence of sexual dimorphism. Females were more likely to fly than the males, and flies that developed on grapefruit covered the shortest distance. Host fruit type influenced both the lipid content and the flight muscle mass, with development in grapefruit leading to the lowest values. Our results show that variation in flight performance of B. dorsalis individuals can be associated with differences in resource quality during their development, and may lead to regional and temporal differences in the ability of the pest to disperse.
South Africa has a diverse assemblage of true fruit flies in the subfamily Dacinae (Diptera: Tephritidae). Amongst its members are species with significant agricultural and ecological importance, yet this is the first comprehensive checklist available for this group in South Africa. This account was compiled using verified specimen lists, which are maintained by the Royal Museum for Central Africa (RMCA) database and includes material from 30 global museum collections. To supplement the database and obtain detailed information on pest status, distribution and known host plant records, additional literature records were sourced. In total, 105 species belonging to ten genera are documented. Of the species recorded, several include key pests of cultivated fruit and vegetables in South Africa, while most are non-pest species restricted to native host plants. In addition to known pest status and host range within South Africa, the observed distribution patterns on a continental and national scale, and the known attractants used for trapping fruit fly specimens are also briefly reported. This resource combines information into a single document and provides support to taxonomic, ecological and applied studies of dacine fruit flies in South Africa, as well as pest risk assessments of relevance to South Africa's fruit exports.
In early 2024, an outbreak of an unknown wood-borer was observed in Acacia mearnsii De Wild (black wattle) compartments in the Midlands of KwaZulu-Natal, South Africa, causing symptoms of excessive resin production. Larvae uncovered beneath the barkwere morphologicallyidentified as a flathead borer, prompting urgent investigation due to the historically low impact of wood-borers on black wattle in South Africa. DNA sequencing of the COI and CytB regions of the larvae failed to yield conclusive matches, so infested logs were collected and the infesting insects reared, resulting in the emergence of three adult beetles. Morphological examination of the adults revealed them as being Agrilus grandis Gory & Laporte 1839, a native African jewel beetle. Comparison to historical specimens housed in the FABI Insect Reference Collection based at the University of Pretoria revealed a previous, unpublished outbreak of the same species in Acacia mearnsii in 1974. However, this is the first official report of A. grandis infestations on A. mearnsii in South Africa.
The generalist egg parasitoid Trichogrammatoidea cryptophlebiae (Nagaraja, 1979) (Hymenoptera: Trichogrammatidae) is mass-reared in South Africa on Thaumatotibia leucotreta (false codling moth). However, alternative tortricid hosts may improve or enhance production. This study assessed the suitability of Cydia pomonella, Cryptophlebia peltastica and Lobesia vanillana as alternative hosts for the parasitoid through no-choice and choice trials. Host acceptance, emergence, superparasitism, unsuccessful emergence, sex ratio, and offspring morphology were measured. In no-choice assays, T. leucotreta and L. vanillana yielded the highest parasitism, while C. peltastica showed significantly less parasitism. Emergence was highest from C. pomonella and C. peltastica, but high superparasitism in these species resulted in increased unsuccessful development compared to the other species. Lobesia vanillana, the smallest host, classified by egg size, produced significantly smaller offspring of the parasitoid. Morphological analyses showed limited differences in forewing length, but significant host-and sex-dependent variation in hind tibia length. Choice trials revealed a consistent preference for T. leucotreta, particularly eggs that had been irradiated, suggesting its continued suitability for mass production of T. cryptophlebiae.These findings highlight key host-related traits affecting T. cryptophlebiae biology and rearing potential and confirm L. vanillana and C. peltastica as physiological hosts.
Udzungwana bispinosa, gen. et sp. n. is described from Tanzania and placed in a new corthyline subtribe Udzungwanina, subtribus n. Although this new subtribe lacks a single diagnostic character, the combination of characters makes it unique both within Corthylini and among other tribes. The new taxon is associated with dead hanging lianas in a tropical rain forest.
The African rice gall midge (AfRGM), Orseolia oryzivora (Diptera: Cecidomyiidae), is a major constraint to rice production in sub-Saharan Africa, causing significant yield losses, particularly under rainfed and irrigated lowland conditions. Farmers often rely on synthetic insecticides, but their high cost, associated environmental concerns and limited effectiveness necessitate sustainable alternatives. This study, conducted from 2023 to 2024 in the rice-growing community of Edozhigi, Niger State, Nigeria, evaluated the efficacy and adoption of neem-lime extract as an eco-friendly management strategy against AfRGM. A 4 x 3 factorial field experiment tested four rice varieties (FARO 37, FARO 44, FARO 66, FARO 67) with two neem-lime extract treatments: seed soaking only and seed soaking plus foliar spray, with a control. In 2023, 80 farmers were trained using a learning-by-doing approach, and adoption was assessed in 2024 through structured questionnaires. Results showed that seed soaking plus foliar spray significantly reduced AfRGM infestation compared to seed soaking alone, particularly when integrated with FARO 67. Tiller infestation negatively correlated with grain yield (R-2 = 0.34-0.84). The extract enhanced yields (5.67 t ha-1 in 2023; 6.92 t ha-1 in 2024) without adverse effects on agronomic traits. Adoption was high (79.5%), influenced by farming experience (chi(2) = 17.00, p = 0.002), farm size (chi(2) = 6.85, p = 0.032) and education level (chi(2) = 24.23, p = 0.001), but not by age or gender. Most adopters (80.6%) prepared the extract themselves. Neem-lime extract, particularly integrating with FARO 67, offers a practical and environmentally friendly alternative to chemical insecticides for AfRGM management.
The genus Culicoides Latreille is represented by 160 described species in the Afrotropical region. Evidence suggests that there may be at least 30 species still need to be described in South Africa. Culicoides baltusi Labuschagne and Meiswinkel†* sp. n. and Culicoides theileri Labuschagne and Meiswinkel sp. n. are described and illustrated for both sexes from material collected in South Africa, Botswana, Namibia and Zimbabwe since 1990. We propose that both species be placed in the subgenus Culicoides Latreille. Morphological and molecular evidence indicate that these two species are related to Culicoides brucei Austen. Culicoides theileri sp. n. is restricted to the drier western areas of the Northern and Western Cape provinces, while C. baltusi sp. n. on the other hand is widely distributed across southern Africa, as is C. brucei. These three species can be separated based on size and wing pattern. Breeding habitat of all three species is not known. Published research utilising precipitin tests and PCR indicate that the adult female blood feeding preferences of C. baltusi sp. n. and C. brucei are large mammals, including bovines and equids. Those of C. theileri sp. n. are not known, though it likely also feeds on large mammals. Extensive light trap data, collected over 30 years, were extracted from the National Collection of Insects of Veterinary Importance (NCIVI) database and are used to map the distribution ranges of C. baltusi sp. n., and C. theileri sp. n. and C. brucei in southern Africa. The description of these two new species increases our understanding of the diversity and distribution of Culicoides species in southern Africa. †*Rudy Meiswinkel is credited as co-author of the two new species as he contributed to the species descriptions prior to his death in 2022.
Native to Southeast Asia, the fly Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), or Spotted Wing Drosophila, has become a major pest of soft-skinned fruits in several countries globally. However, its distribution in sub-Saharan Africa was limited to Kenya and some Indian Ocean Islands. In 2021, an industry-funded surveillance project was initiated to determine whether the pest was present in the Western Cape and Eastern Cape provinces of South Africa. Trapping was conducted using lures developed for this species in bucket-type traps. The first D. suzukii detection was of a single male, trapped on the 25th of April 2022 in the Langkloof region in the Eastern Cape province. This research presents the first report of D. suzukii occurring within South Africa. We also present the results of ongoing surveys showing the current spread of the pest in South Africa.
Worldwide introductions of non-native bark and ambrosia beetles (Coleoptera: Scolytinae) are increasing, with several species now capable of attacking living trees and introducing pathogenic fungi having been recorded in naïve habitats. Here we provide the first record of the exotic Amasa parviseta Knížek & Smith 2024 in continental Africa, based on four specimens collected across the Western Cape province of South Africa. This species is known to primarily colonise stressed or dying Eucalyptus and other Myrtaceae species. While no impacts have thus far been documented locally on commercially grown Eucalyptus, the species’ known ability to vector pathogenic fungi in other regions highlights its potential threat to not only South Africa’s commercial forestry industry but also its native species of Myrtaceae. We recommend targeted monitoring of this non-invasive species and investigations into its symbiotic fungi for potential phyto-pathogenicity. The discovery of this potentially harmful exotic species in South Africa underscores the importance of ongoing surveillance for non-native scolytine beetles to ensure early detection, proper risk assessment, and phytosanitary interventions to prevent establishment and mitigation of possible negative impacts.
The simplification of landscapes associated with monocrop agriculture reduces the availability of habitats for beneficial arthropods that provide essential ecosystem services. Arthropod diversity can be increased through landscape enhancement, e.g. the cultivation of refuge strips (CRS). The aim of this pilot study was to investigate the effect of CRS, which is a novel management strategy in South Africa, on arthropod diversity in maize fields. Arthropod diversity and species composition was assessed along a transect from within CRS into two maize fields. The study was conducted on a large-scale commercial maize farm in the North-West province of South Africa. Two sampling methods were used (pitfall and pan traps). Traps were placed along three transects in each maize field during the pre-flowering and flowering stages of the maize crop. Each transect consisted of traps at the following distances: 0 m (within CRS), 5 m, 10 m and 20 m into the maize fields. A total of 270 pitfall and 270 pan trap samples were collected during this study. All arthropods were identified to morpho-species level and counted after which the Shannon-Wiener diversity (H’), Pielou’s evenness (J’) and Margalef’s diversity (d) were calculated. A total of 20 134 arthropods of 283 morpho-species were collected. Epigeal and flying arthropod diversity decreased as distance increased from the CRS. This trend was mirrored by the Pielou’s evenness index for epigeal arthropods while the evenness of flying arthropods indicated no clear pattern. Distinct arthropod communities were present within the CRS and the maize field. This pilot study indicates that the CRS supported a diverse arthropod community during the flowering stages of maize. However, as distance from the CRS increased, arthropod diversity decreased. Further studies should be conducted to determine the diversity within refuges and maize fields throughout the cropping season, as well as at longer distances away from refuges.
The Afrotropical hover flies placed in the genus Eristalis Latreille, 1804 (Diptera: Syrphidae) are revised and the taxonomic history of the placement, and identity, of the different species is presented. Five species are recognised, of which only three can be clearly defined: E. pallidibasis (Bigot, 1891), E. plumipes Bezzi ,1912, and E. tenax (Linnaeus, 1758). Eristalis apis Curran, 1939 syn. nov. is proposed as a junior synonym of E. pallidibasis (Bigot, 1891). Eristalis convexifacies Macquart, 1850 is known only from a badly damaged holotype. The identity of Simoides trichopus Bigot, 1891, (now considered to be an Eristalis) is uncertain as its type material could not be traced and the original description lacks sufficient detail. For the time being, S. trichopus is considered a nomen dubium. An identification key and detailed redescriptions are provided. Eristalis pallidibasis, E. plumipes and E. tenax are easily identified using DNA barcoding. The relationship of Afrotropical Eristalis with Afrotropical representatives of other eristaline genera is briefly discussed based on morphological data.
