Three species of the africana-group of the Genus Gryllotalpa (Orthoptera: Gryllotalpidae) were recorded from Cameroon during an investigation from March 2016 to March 2018: Gryllotalpa africana Beauvois from Buea and Tombel, and two new species, Gryllotalpa tombelensis Simeu-Noutchom and Kekeunou sp. nov. from Tombel and Gryllotalpa babetensis Simeu-Noutchom and Kekeunou sp. nov. from Babété. Gryllotalpa tombelensis is characterised by short wing morphology, vestigial hind wings, small phallic complex, short internal processes, and dorsoventrally flattened body. Gryllotalpa babetensis is distinct from other species of the africana-group by the mesoscutum being more exposed between the pronotum and the base of the fore wings, having a very large phallic complex, with very long internal processes of ectophallus (3 mm long). Both new species were collected in crop fields, but which differ in their habitat characteristics, such as soil moisture, pH and granulometry. A key and comments on the africana-group species of the genus Gryllotalpa and their habitat characteristics are also provided. The finding of the present study aims to help species identification and will help future taxonomists concerned with biodiversity of this group from Cameroon.

The cane rat (Thryonomys swinderianus) is a wild animal recently domesticated in Africa for meat production. The effect of dietary fibre levels on the digestive health and growth in the young cane rat remains largely unknown. Dietary fibre intake, however, seems to play an important role in its digestive functioning. The aim of this study was to investigate the effect of dietary fibre intake on young cane rats. The estimated optimal dietary fibre content of pelleted diets, which optimised growth without impairing health in young T. swinderianus was examined. The feed intake, growth and health of young cane rats were assessed for four diets with dietary fibre levels set at 7, 12, 20 and 24% acid detergent fibre (ADF) on four groups of 18 animals each. Growth was best with the 12% ADF diet followed by 20% ADF diet, with average live weights reaching 1 404 g and 1 325 g, respectively, at 114 days of age. In contrast and compared with the 12% ADF diet, the 24% ADF diet resulted in a 9% weight reduction. Additionally, the 7% ADF diet led to a 33% mortality rate due to enteritis (without diarrhoea), but was associated with inflammation in the stomach and small intestine. We conclude that the optimal fibre content for growing cane rats fed on complete pelleted diets would be between 12% and 20%.

Biological invasions by agricultural pests can have serious negative impacts, including decreases in crop yield and economic losses. The MT-1 and MT-8 genotypes of the wheat curl mite (Aceria tosichella) (hereafter ‘WCM’ refers to these two genotypes) are globally distributed pests of wheat and maize that have not been recorded in South Africa. This study examined whether WCM could be introduced to, and establish in, South Africa. Trade data were used to determine whether viable pathways of introduction are present. A species distribution model and data on wheat and maize production were used to determine whether WCM could establish where its hosts are grown. WCM is most likely to be introduced to South Africa as a contaminant of maize from Argentina, Brazil, Uruguay, and USA; on live plant imports from China and Germany; and on seed imports from Brazil and Australia. Some of these pathways are not currently prominent, but could increase in the future. Parts of South Africa were predicted by the species distribution model to be climatically suitable for WCM, and within some of these areas the host crops are grown. Therefore, if WCM is introduced, it is likely to establish and cause extensive damage to agriculture. We recommend that WCM be considered for inclusion in South Africa's import conditions as a quarantine pest.

Climate and land use change are anticipated to alter the distribution of wildlife, due to their impact on the quantity and quality of forage availability, water cycle, as well as competition for key resources. Using an ensemble of species distribution models (SDMs), we sought to predict changes in the distribution of the African elephant (Loxodonta africana) in response to climatic and land cover change in Africa. We found that African elephant distribution is driven predominantly by changes in temperature followed by changes in precipitation and land cover. Our results show that 17.1% of the continent shows high suitability for L. africana under the current climatic conditions, while 56.6% is unsuitable under similar climatic conditions. The modelled current suitability shows that high and moderately suitable areas for L. africana are predicted to occur in the eastern, southern and part of western Africa. In 2050, unsuitable area for elephants under Representative Concentration Pathway (RCP) 4.5 and RCP 8.5 is projected to increase by 12.7% and 14.1%, respectively. In contrast, the highly suitable area for L. africana is projected to decrease by 51.3% and 67.6% under RCP 4.5 and RCP 8.5, respectively. Compared to the current climatic conditions, in 2070 highly suitable areas for L. africana are projected to decrease by 74.5% and 85.9% under RCP 4.5 and RCP 8.5 scenarios, respectively. Climate change and land cover change are expected to worsen and become one of the major drivers for the loss of several wildlife species like the African elephant due to their impact on availability of water and forage. Therefore, conservation and management of elephant populations under global change calls for carefully designed migratory corridors and conservation of trans-frontier landscapes to enable dispersal of the elephants and other associated species to more conducive environments.

The bean Phaseolus vulgaris is widely consumed by the Congolese population, because it is rich in protein and has a good nutritional quality. Beetles of the subfamily Bruchinae are pests of bean seeds in the field and storage in the Republic of Congo (RC). Their attacks cause a reduction in seed weight, leading to a decrease in the nutritional and commercial value of the seeds. The purpose of our study was to identify the post-harvest diversity of bean bruchids in two bean producing regions in the Congo (Niari and Bouenza) using molecular taxonomy (12S rRNA marker). The bean weevil, Acanthoscelides obtectus (Say), and cowpea weevil, Callosobruchus maculatus (Fabricius), were identified. Acanthoscelides obtectus, recognised as the main pest of beans, was found in all ten localities sampled, whereas C. maculatus, recognised as the main pest of pigeon peas (Cajanus cajan) and chickpeas (Cicer arietinum), was found in two of the ten. Better knowledge of the diversity of bruchids present in the RC will make it possible to propose effective control methods with little impact on environmental and human health.

The alien invasive mussel, Mytilus galloprovincialis, forms biogenic habitats in the embayment of Knysna Estuary. Invertebrate macrofauna inhabiting mussel beds were sampled from six sites in the embayment. In addition, mussel cover, mussel bed depth, density and size of mussels were recorded. With the exception of two sites (The Heads and Featherbed) where some Perna perna was present, we confirmed that the mussel beds were composed of the invasive species M. galloprovincialis. At The Heads, mussel beds were single-layered and in patches, whereas at other sites they were multi-layered with 100% cover. Bed depth, mussel density and shell size varied among sites. A total of 65 taxa (mainly Crustacea and Mollusca) were identified across all sites with species richness and diversity being significantly different among sites. Forty-three percent of taxa were new records for the estuary. Macrofaunal richness and diversity were highest at the two sites (The Heads and Featherbed) closest to the mouth of the embayment. There were negative relationships between species diversity and mussel density, and diversity and macroinvertebrate abundance. At most sites macrofaunal abundance was dominated by one or two species. Multivariate analysis revealed a significant difference in species composition among sites. Where wave action was present (The Heads, Featherbed and Leisure Isle) only a few deposit feeders were present in the mussel beds. At sites where wave action was minimal (Thesen Wharf, Marina and Railway Bridge) fine silt was present in the mussel matrix and there was an increase in the number of deposit feeding species.

Birds select breeding habitats based on biotic and abiotic environmental factors, resulting in a non-random spatial distribution of nests. This study investigated the onset of nesting, nest location, the relationship between nest height and water depth, nest materials, and the structure and characteristics of Black Crowned Crane nests in the Lake Tana region, Ethiopia. A total of 52 nests were recorded in four wetlands from 2014 to 2015. Nesting activity predominantly took place from September to October. There was a significant difference in the distance from nests to the edge of the wetland (χ² = 24.843, n = 46, df = 3, p < 0.001). However, in all study areas the distance between nests, which indicates the degree of territoriality, did not show any significant difference (χ² = 6.016, n = 34, df = 3, p = 0.111). In addition, nests were constructed in the wetland where the water depth ranged from 80 to 220 cm. Nest height (H_2i) and water depth (WD_i) at nesting sites were highly correlated, and the regression equation (H_2i = 13.77 + 1.03WD_i) indicated that when the water depth increases, the nest height also increases. The shallowest depth where a nest was constructed was 80 cm. Vegetation type varied, but cranes used Leersia hexandra, Oryza longistaminata, and Cyprus rotundus plants as their selected nesting material. The average vegetation height observed at nests with eggs, measured one metre away from the nest rim, ranged from 20 to 90 cm (44.83 ± 2.397), n = 48. The vegetation height at each study site showed no significant difference (F₍₃₎ = 2.527, p = 0.07). The mean nest length, width, and height from the surface of the water between nests were not significantly different. Nesting density was variable depending on the size of the wetland, water depth, and vegetation type and cover.

Mosquito resistance to insecticides has recently increased the burden of the majority of mosquito-borne diseases, and controlling the spread of these diseases should mainly rely on vector control measures. The present study aimed to investigate the toxicity of locally isolated mosquitocidal Bacillus thuringiensis (Bt) isolates and toxin complexes (TCs) from the two nematode bacterial symbionts Photorhabdus luminescens akhurstii (HRM1) and Photorhabdus luminescens akhurstii (HS1) on Aedes caspius. Out of sixty-eight local Bt isolates, four showed LC₅₀ values ranging from 13.8–15.6 ppm, similar to LC₅₀ recorded against the reference Bacillus thuringiensis israelensis (Bti-H14) (13.0 ppm). Seventeen isolates were more toxic than the Bti-H14 by 1.3–11.1 fold (LC₅₀ values 1.17–9.9 ppm vs 13.0 ppm). Two isolates were less toxic than Bti-H14, showing LC₅₀ values of 39.4 and 24.1 ppm, respectively. Additionally, the TCs from HRM1 and HS1 showed promising larvicidal toxicity, with HS1 being 2.74 fold more toxic than HRM1. Larval morphological features and body size were altered upon HS1 toxin-treatment. This study suggests that there is a new effective local Bt strain, and TCs toxin complexes could be used as eco-friendly biocontrol agents that might contribute to controlling mosquito-borne diseases. The synergistic effect of the Bt-TCs combination on mosquito larvae should be further investigated.

Multimammate mice (Mastomys natalensis) are a key rodent pest species to cereal crop production in Sub-Saharan Africa. This study aimed at generating information on the population fluctuation and breeding patterns of M. natalensis in a maize dominated agro-ecosystem in the Mayuge district, Eastern Uganda. The area is characterised by a bimodal rainfall pattern with rains in the periods March to May and August to November. A Capture–Mark–Recapture study was established in cultivated and fallow field habitats with, in each habitat, two plots of 60 m by 60 m with 49 evenly spaced trapping points. Trapping was conducted monthly for three consecutive nights, and the study extended from January 2016 to June 2018. A Generalised Linear Mixed Model analysis showed significantly higher population density estimates (β = 0.69, p < 0.0001) in fallow land compared to cultivated fields, and also significantly higher density estimates(β = 0.75, p = 0.006) in the first wet season and lowest in the first dry season. The percentage breeding females differed significantly across months (χ² = 27.05, df = 11, p = 0.003) and seasons (χ² = 17.64, p = 0.0003). Breeding females occurred throughout all the months of trapping, but with significantly higher percentages in the months of March to July (i.e. first wet season extending to second dry season) and generally lowest in the first dry months (i.e. January and February in 2017, and February 2018). The results of this study have important consequences for the timing of control efforts, and recommends that control should be initiated during the dry seasons prior to wet seasons to counteract potential damaging population build up in later wet seasons when crop planting is expected.