Research Articles (Forestry and Agricultural Biotechnology Institute (FABI))

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Gene transfer between fungal species triggers repeated coffee wilt disease outbreaks
(Public Library of Science, 2024-12-06) Wingfield, Brenda D.; Wingfield, Michael J.; brenda.wingfield@fabi.up.ac.za
Two outbreaks of coffee wilt disease have devastated African coffee production. A PLOS Biology study suggests that horizontal gene transfer via large Starship transposons between 2 fungal species played a key role in the repeated emergence of the disease.
Chalaropsis pruni sp. nov. (Ceratocystidaceae), a new species from Prunus serrulata var. pubescens in South Korea
(Magnolia Press, 2024-11-12) Cho, Sung-Eun; Seo, Sang-tae; Nam, Youngwoo; Wingfield, Michael J.; Lee, Dong-hyeon
A routine survey in a natural forest located in the Gangwon Province of Korea was undertaken in 2022 to establish an inventory of potentially pathogenic fungi that might affect tree health in the country. An ophiostomatoid fungus was consistently isolated from naturally occurring wounds on Prunus serrulata var. pubescens. Isolates were subjected to morphological and DNA sequence comparisons. The results showed that the fungus resided in a distinct taxonomic lineage, and the novel species is described here as Chalaropsis pruni sp. nov.
Transgenerational cross-susceptibility to heat stress following cold and desiccation acclimation in the angoumois grain moth
(Wiley, 2024-12) Mpofu, Precious; Machekano, Honest; Airs, Paul M.; Nyamukondiwa, Casper
The Angoumois grain moth, Sitotroga cerealella (Olivier), is a significant cosmopolitan primary pest of cereals worldwide and has thrived in divergent environments. However, the mechanisms underlying its survival in multiple contrasting environments are poorly understood. Here, we hypothesised that when facing diverse environmental stress, F1 generation exhibits transgenerational cross-protection as a mechanism to persist under divergent stressful environments. Notably, F1 acclimation to cold or desiccation conditions could either enhance or lower heat tolerance in the F2 generation. Specifically, we tested whether typical diurnal fluctuations and/or winter rapid or chronic cold temperatures (18–22 C) as well as desiccation acclimation of F1 parental population yields transgenerational cross-protection/susceptibility to heat stress on F2 offspring. F1 moths were exposed to cold hardening (2 h), chronic (72 h) and variable (fluctuating between 18 and 22 C for 72 h) temperature treatment groups. Desiccation treatment included incubation at 0%–1% relative humidity (24 h). F2 generation moths were then assessed for heat tolerance using critical thermal maxima (CTmax) at three different ramping rates (0.06, 0.25 and 0.5 C/min) as well as heat knockdown time (HKDT). Findings indicated that (i) desiccation, cold hardening and chronic low-temperature acclimations in F1 reduced heat tolerance in F2 populations and (ii) ramping rate was crucial to decipher differences between treatment groups, with lower ramping rates associated with lower CTmax. Transgenerational cross-susceptibility to heat stress indicates possible fitness costs of exposure to multiple contrasting stressors in the Angoumois grain moth and can be used in designing physical pest management strategies.
Fine scale patterns and drivers of plant species richness on a sub-Antarctic island
(Wiley, 2025-03) Tsamba, Joshua; Le Roux, Peter Christiaan; Pertierra, Luis R.; Kuhlase, Bongekile Sinenhlanhla Nontokozo; Greve, Michelle
AIMS : Cold environments, such as polar systems, are highly vulnerable to global change drivers such as climate change and invasive species. Therefore, it is essential to assess what drives the diversity of native and invasive species in these systems. LOCATION : We investigated what drives native and alien plant species richness on sub-Antarctic Marion Island and determined the scale-dependence of these drivers. METHODS : Native and alien plant species richness was surveyed at “small” (1 m2) and “large” (9 m2) sampling grains. Difference in richness between the two sampling grains was calculated to assess how local turnover contributes to species assemblage. The factors driving richness at both grains, and the differences in richness between the two grains, were analysed using simultaneous auto-regressive models. Drivers related to energy and environmental heterogeneity were correlated with native richness, whilst drivers related to productivity were related to alien richness. RESULTS : Biotic interactions with a cushion plant facilitated native richness, but restricted alien richness at low elevations. Further, some drivers of richness depended on spatial grain. Native richness was positively related to northness at large, but not small grain size, suggesting that higher northness increases local turnover at a grain size > 1 m2. On the other hand, topographical wetness index (TWI) boosted native richness at small but not large grains, implying that competition for water limits coexistence at low TWI (i.e., low moisture availability) only at small grain. Differences in native species richness between large and small grain sizes were more pronounced at low elevations, suggesting higher compositional heterogeneity at low altitudes. CONCLUSIONS : Our study highlights that drivers of plant species richness in a polar ecosystem differ between native and alien plant species. Additionally, the effects of some drivers on richness differ between sampling grains, and considering these differences provides insight into drivers of local patterns of species assemblage.
Survey of farmers' knowledge of yam pests and diseases and management practices in southern Ethiopia
(Oxford University Press, 2024-11) Gogile, Ashebir; Kebede, Misrak; Wada, Eyasu; Kidanemariam, Dawit B.; Abraham, Adane
Yam is a widely consumed food in the tropics and subtropics. Determination of pests (pathogens and insects) and diseases (developed pest invasions and symptoms) and the appropriate management practices are critical in existing crop production systems. This study aimed to document farmers’ knowledge about yam pests and diseases and their management practices in southern Ethiopia. Data were collected from 342 systematically selected farmers and 96 yam fields in 5 major yam-growing zones (Dawuro, Gofa, Gamo, Kembata-Tembaro, and Wolaita) in southern Ethiopia using a semi-structured interview guide. The results showed that 54.1% of the farmers saved their planting materials for the next growing season, while 39.2% of the farmers purchased the planting materials from the local market every year. Most farmers (63.5%) reported that the cultivation of yam has been declining annually due to pests and diseases. White yam (Dioscorea rotundata) (Poir, Dioscoreales, Dioscoreaceae) and water yam (Dioscorea alata) are severely damaged by pests and diseases, as perceived by 33.9% and 24.9% of farmers, respectively. Farmers use healthy-looking pest- and disease-free tubers (39.5%), remove infected plants (24.0%), practice crop rotations (17.3%), and use animal manure (7.0%) to manage yam pests and diseases. Farmers’ knowledge can be a starting point for seeking solutions to yam pests and disease risks. This study could play an important role in improving yam cultivation by identifying strategies to improve the recent decline in yam production to meet future food needs for a rapidly growing population.
The ascorbate-glutathione cycle coming of age
(Oxford University Press, 2024-05-03) Foyer, Christine H.; Kunert, Karl J.
Concepts regarding the operation of the ascorbate–glutathione cycle and the associated water/water cycle in the processing of metabolically generated hydrogen peroxide and other forms of reactive oxygen species (ROS) are well established in the literature. However, our knowledge of the functions of these cycles and their component enzymes continues to grow and evolve. Recent insights include participation in the intrinsic environmental and developmental signalling pathways that regulate plant growth, development, and defence. In addition to ROS processing, the enzymes of the two cycles not only support the functions of ascorbate and glutathione, they also have ‘moonlighting’ functions. They are subject to post-translational modifications and have an extensive interactome, particularly with other signalling proteins. In this assessment of current knowledge, we highlight the central position of the ascorbate– glutathione cycle in the network of cellular redox systems that underpin the energy-sensitive communication within the different cellular compartments and integrate plant signalling pathways.
Polyandry contributes to Gonipterus platensis (Coleoptera: Curculionidae) rearing
(PeerJ Inc., 2024-08) Ribeiro, Murilo F.; Cavallini, Gabriela; Solce, Gabriel N.; Favoreto, Ana L.; De Souza Passos, José R.; Hurley, Brett Phillip; Wilcken, C.F.
BACKGROUND: Gonipterus platensis Marelli, 1926 (Coleoptera: Curculionidae) is one of the main defoliating beetles in Eucalyptus plantations. Biological control with egg parasitoids is one of the main control strategies for this pest and a constant supply of fresh host eggs is required to rear the parasitoids. Polyandry can influence Gonipterus oviposition by increasing female fecundity and fertility; however, the high density of individuals in laboratory colonies can lead to male harassment, resulting in lower reproduction rate. The aim of this study was to measure the effects of monoandry and polyandry on the reproduction of G. platensis and the effects of male harassment on laboratory rearing conditions. METHODS: Reproductive parameters were compared between three treatments: monoandry, where the female was allowed to mate daily with the same male; no choice polyandry, where the female was allowed to mate daily with a different male; and polyandry with choice, where the female was allowed to mate daily, but with a choice between five different males. Another experiment varying the density of males was conducted to evaluate the effect of male harassment. RESULTS: Polyandry with choice resulted in the longest period of oviposition, highest fecundity and highest number of eggs per egg capsules when compared to monoandrous females. No negative effect related to male harassment in the laboratory, such as decreased fertility, fecundity, or number of eggs per egg capsule, was detected. CONCLUSION: Polyandry contributes to mass rearing as it increases fecundity and oviposition period on females and there is no evidence of male harassment on G. platensis.
Chromosome-level assemblies for the pine pitch canker pathogen Fusarium circinatum
(MDPI, 2024-01) De Vos, Lieschen; Van der Nest, Magrieta Aletta; Santana, Quentin C.; Van Wyk, Stephanie; Leeuwendaal, Kyle; Wingfield, Brenda D.; Steenkamp, Emma Theodora; emma.steenkamp@fabi.up.ac.za
The pine pitch canker pathogen, Fusarium circinatum, is globally regarded as one of the most important threats to commercial pine-based forestry. Although genome sequences of this fungus are available, these remain highly fragmented or structurally ill-defined. Our overall goal was to provide high-quality assemblies for two notable strains of F. circinatum, and to characterize these in terms of coding content, repetitiveness and the position of telomeres and centromeres. For this purpose, we used Oxford Nanopore Technologies MinION long-read sequences, as well as Illumina short sequence reads. By leveraging the genomic synteny inherent to F. circinatum and its close relatives, these sequence reads were assembled to chromosome level, where contiguous sequences mostly spanned from telomere to telomere. Comparative analyses unveiled remarkable variability in the twelfth and smallest chromosome, which is known to be dispensable. It presented a striking length polymorphism, with one strain lacking substantial portions from the chromosome’s distal and proximal regions. These regions, characterized by a lower gene density, G+C content and an increased prevalence of repetitive elements, contrast starkly with the syntenic segments of the chromosome, as well as with the core chromosomes. We propose that these unusual regions might have arisen or expanded due to the presence of transposable elements. A comparison of the overall chromosome structure revealed that centromeric elements often underpin intrachromosomal differences between F. circinatum strains, especially at chromosomal breakpoints. This suggests a potential role for centromeres in shaping the chromosomal architecture of F. circinatum and its relatives. The publicly available genome data generated here, together with the detailed metadata provided, represent essential resources for future studies of this important plant pathogen.
Sex pheromone receptor Ste2 orchestrates chemotropic growth towards pine root extracts in the pitch canker pathogen Fusarium circinatum
(MDPI, 2024-05) Ramaswe, J.B.; Steenkamp, Emma Theodora; De Vos, Lieschen; Fru, Felix Fon; Adegeye, O.O.; Wingfield, Brenda D.; emma.steenkamp@fabi.up.ac.za
In ascomycetous fungi, sexual mate recognition requires interaction of the Ste2 receptor protein produced by one partner with the α-factor peptide pheromone produced by the other partner. In some fungi, Ste2 is further needed for chemotropism towards plant roots to allow for subsequent infection and colonization. Here, we investigated whether this is also true for the pine pitch canker fungus, Fusarium circinatum, which is a devastating pathogen of pine globally. Ste2 knockout mutants were generated for two opposite mating-type isolates, after which all strains were subjected to chemotropism assays involving exudates from pine seedling roots and synthetic α-factor pheromone, as well as a range of other compounds for comparison. Our data show that Ste2 is not required for chemotropism towards any of these other compounds, but, in both wild-type strains, Ste2 deletion resulted in the loss of chemotropism towards pine root exudate. Also, irrespective of mating type, both wild-type strains displayed positive chemotropism towards α-factor pheromone, which was substantially reduced in the deletion mutants and not the complementation mutants. Taken together, these findings suggest that Ste2 likely has a key role during the infection of pine roots in production nurseries. Our study also provides a strong foundation for exploring the role of self-produced and mate-produced α-factor pheromone in the growth and overall biology of the pitch canker pathogen.
Inconsistencies within the proposed framework for stabilizing fungal nomenclature risk further confusion
(American Society for Microbiology, 2024-04) Kidd, Sarah E.; Hagen, Ferry; Halliday, Catriona L.; Abdolrasouli, Alireza; Boekhout, Teun; Crous, Pedro W.; Ellis, David H.; Elvy, Juliet; Forrest, Graeme N.; Groenewald, Marizeth; Hahn, Rosane C.; Houbraken, Jos; Rodrigues, Anderson M.; Scott, James; Sorrell, Tania C.; Summerbell, Richard C.; Tsui, Clement K.M.; Yurkov, Andrey M.; Chen, Sharon C.-A.
We read with interest the recent publication by de Hoog and colleagues in the Journal of Clinical Microbiology (1) and support the goal to stabilize fungal nomenclature. Although we recognize the importance of stable naming, we offeroffercomments on the need for clarity around the concepts introduced, consistency of the recommended nomenclature, process issues regarding the endorsement by professional groups and societies and the proposed oversight committee (working group), and the relationship between the proposed database and existing, officially recognized nomenclatural repositories.
The impact of past and current district-level climatic shifts on maize production and the implications for South African farmers
(Springer, 2025-02) Mangani, Robert; Mazarura, Jocelyn; Matlou, Solly; Marquart, Arnim; Archer, Emma Rosa Mary; Creux, Nicky; nicole.creux@fabi.up.ac.za
South Africa’s climate studies generally focus on coarser provincial levels, which aid policy recommendations, but have limited application at the farm level. District level climate studies are essential for farmer participation in climate change mitigation strategies and management. Our study aimed to investigate historical climate data for trends and their influence on maize yields at the magisterial level. Six sites were selected from three major maize-producing provinces in South Africa: Mpumalanga, Northwest, and Free State. Magisterial districts in each province were selected from different Köppen-Geiger climate zones. The climate variables assessed by the Mann–Kendall trend test included maximum or minimum temperature, rainfall, number of extreme high-temperature days, rainfall onset and cessation from 1986 to 2016. The average maximum temperatures were observed to have significant upward trends in most locations, except for Schweizer-Reneke and Bethlehem. The fastest rate of change was observed at Klerksdorp (0.1 °C per 30 years of study), while the Schweizer-Reneke district was the slowest (0.05 °C per 30 years of study). No significant changes were observed in rainfall onset, cessation, or total rainfall in Schweizer-Reneke, Standerton, and Bethlehem, which are scattered across the different provinces. The other districts in each province showed significant changes in these parameters. Rainfall accounted for the significant variation in maize yields over the study period, explaining between 18 and 40% of the variation in the North West, and between 1 and 17% in the Free State. These findings highlight the importance of understanding location-specific changes at a finer scale, which can help farming communities adjust agronomic practices and adapt to local climate shifts.
Addition of selected plant-derived semiochemicals to yellow sticky traps does not improve citrus psyllid captures
(Springer, 2024-11) Pullock, Dylan Andrew; Kruger, Kerstin; Manrakhan, Aruna; Yusuf, Abdullahi Ahmed; Pirk, Christian Walter Werner; cwweldon@zoology.up.ac.za
Fast and effective monitoring and surveillance techniques are crucial for the swift implementation of control methods to prevent the spread of Huanglongbing, a devastating citrus disease, and its invasive psyllid vector, Asian citrus psyllid, Diaphorina citri, into South Africa, as well as to control the native vector, African citrus triozid, Trioza erytreae. Monitoring for citrus psyllid pests can be improved by using semiochemical odorants to augment already visually attractive yellow sticky traps. However, environmental variables such as temperature and humidity could influence odorant release rates. Five field cages were used to test the ability of a selection of odorants to improve yellow sticky trap efficacy in capturing citrus psyllids. Environmental effects on odorant loss from the dispensers were also investigated. The odorants that most improved yellow sticky trap captures in field cages were then tested under open field conditions alongside lower concentrations of those same lures. Gas chromatography-mass spectrometry was used to calculate odorant release rates as well as to determine if any contamination occurred under field conditions. None of the odorants under field cage or field conditions significantly improved psyllid capture on yellow sticky traps. Temperature influenced odorant loss, and release rate from polyethylene bulbs decreased over time. Based on these results, the use of unbaited yellow sticky traps seems to be the most effective method for monitoring of Huanglongbing vectors.
Effects of physiological status and environmental factors on the lure responses of three pest fruit fly species (Diptera: Tephritidae)
(Springer, 2024-11) Pogue, Tania; Malod, Kevin; Weldon, Christopher William; cwweldon@zoology.up.ac.za
Biotic and abiotic factors influence how insects respond to stimuli. This can make it challenging to interpret captures in traps used to monitor pest abundance in management programmes. To address this, the lure response of three pest fruit flies (Diptera: Tephritidae) was evaluated in a semi-field setting with respect to several physiological and environmental factors. Using standardised methods with known fly numbers in field cages, the response to Biolure (food-based lure) was evaluated for Ceratitis capitata, Ceratitis cosyra and Bactrocera dorsalis. Response to the male lures was tested: E.G.O PheroLure for C. capitata and C. cosyra, Trimedlure for C. capitata, and methyl eugenol for B. dorsalis. The physiological variables evaluated were fly age, sex, weight, and total body nutritional composition. The environmental effects of temperature, relative humidity and light intensity were also assessed. Protein-deprived adults responded more strongly to Biolure. The response to Biolure was not sex-specific. Fly age influenced the response of all species to all tested lures. However, this effect was species and lure specific. Temperature was the most influential environmental factor, with response generally increasing with temperature. Lower thresholds for lure response, despite the proximity of responsive flies, range from 12.21 to 22.95 °C depending on the species and lure tested. These results indicate that trapping systems and management activity thresholds must take physiological and environmental variation into account to increase their accuracy.
Biogeography and global flows of 100 major alien fungal and fungus-like oomycete pathogens
(Wiley, 2024-04) Schertler, Anna; Lenzner, Bernd; Dullinger, Stefan; Moser, Dietmar; Monteiro, Miguel; Reino, Luis; Wingfield, Michael J.; Seebens, Hanno; Thines, Marco; Dawson, Wayne; Van Kleunen, Mark; Kreft, Holger; Pergl, Jan; Pysek, Petr; Weigelt, Patrick; Winter, Marten; Essl, Franz
AIM : Spreading infectious diseases associated with introduced pathogens can have devastating effects on native biota and human livelihoods. We analyse the global distribution of 100 major alien fungal and oomycete pathogens with substantial socio-economic and environmental impacts and examine their taxonomy, ecological characteristics, temporal accumulation trajectories, regional hot- and coldspots of taxon richness and taxon flows between continents. LOCATION : Global. TAXON : Alien/cryptogenic fungi and fungus-like oomycetes, pathogenic to plants or animals. METHODS : To identify over/underrepresented classes and phyla, we performed Chi2 tests of independence. To describe spatial patterns, we calculated the region-wise richness and identified hot- and coldspots, defined as residuals after correcting taxon richness for region area and sampling effort via a quasi-Poisson regression. We examined the relationship with environmental and socio-economic drivers with a multiple linear regression and evaluated a potential island effect. Regional first records were pooled over 20-year periods, and for global flows the links between the native range to the alien regions were mapped. RESULTS : Peronosporomycetes (Oomycota) were overrepresented among taxa and regional taxon richness was positively correlated with area and sampling effort. While no island effect was found, likely due to host limitations, hotspots were correlated with human modification of terrestrial land, per capita gross domestic product, temperate and tropical forest biomes, and orobiomes. Regional first records have increased steeply in recent decades. While Europe and Northern America were major recipients, about half of the taxa originate from Asia. MAIN CONCLUSIONS : We highlight the putative importance of anthropogenic drivers, such as land use providing a conducive environment, contact opportunities and susceptible hosts, as well as economic wealth likely increasing colonisation pressure. While most taxa were associated with socio-economic impacts, possibly partly due to a bias in research focus, about a third show substantial impacts to both socio-economy and the environment, underscoring the importance of maintaining a wholescale perspective across natural and managed systems.
Preliminary characterization of volatile organic compounds in African clawless otter Aonyx capensis spraint
(IUCN Otter Specialist Group, 2024) Nicolaides, Stephanie G.; Hammerbacher, Almuth; McIntyre, Trevor
Chemical communication plays an important role in mate selection, territoriality, resource guarding, parental care and disease transmission in many taxa. Studies investigating olfactory communication and scent communication in wild animal populations are rare. To date there has been no analysis of the odours encoded in African clawless otter anal gland secretions. The volatile organic compound profiles of 14 wild African clawless otter anal gland secretion and faecal samples were investigated to determine the composition of odour profiles and infer on the potential role of particular compounds. Faecal and anal gland secretions were analysed through gas chromatography mass spectrometry. Across all samples a total of 73 compounds were found of which a total of 34 were provisionally identified. Nine of the identified compounds function as sex pheromones and/or reproductive status signals in other vertebrates, suggesting that African clawless otter latrines likely also play an important role in reproductive communication between individuals of the species. Further studies matching the identities of known individual African clawless otters and their reproductive status with the olfactory characteristics of their spraint are required to further validate the interpretations reported here.
Ecological success of extreme halophiles subjected to recurrent osmotic disturbances is primarily driven by congeneric species replacement
(Oxford University Press, 2024-11) Bustos-Caparros, Esteban; Viver, Tomeu; Gago, Juan F.; Rodriguez-R, Luis M.; Hatt, Janet K.; Venter, S.N. (Stephanus Nicolaas); Fuchs, Bernhard M.; Amann, Rudolf; Bosch, Rafael; Konstantinidis, Konstantinos T.; Rossello-Mora, Ramon
To understand how extreme halophiles respond to recurrent disturbances, we challenged the communities thriving in salt-saturated (∼36% salts) ∼230 L brine mesocosms to repeated dilutions down to 13% (D13 mesocosm) or 20% (D20 mesocosm) salts each time mesocosms reached salt saturation due to evaporation (for 10 and 17 cycles, respectively) over 813 days. Depending on the magnitude of dilution, the most prevalent species, Haloquadratum walsbyi and Salinibacter ruber, either increased in dominance by replacing less competitive populations (for D20, moderate stress conditions), or severely decreased in abundance and were eventually replaced by other congeneric species better adapted to the higher osmotic stress (for D13,strong stress conditions). Congeneric species replacement was commonly observed within additional abundant genera in response to changes in environmental or biological conditions (e.g. phage predation) within the same system and under a controlled perturbation of a relevant environmental parameter. Therefore, a genus is an ecologically important level of diversity organization, not just a taxonomic rank, that persists in the environment based on congeneric species replacement due to relatively high functional overlap (gene sharing), with important consequences for the success of the lineage, and similar to the success of a species via strain-replacement. Further, our results showed that successful species were typically accompanied by the emergence of their own viral cohorts, whose intra-cohort diversity appeared to strongly covary with, and likely drive, the intra-host diversity. Collectively, our results show that brine communities are ecologically resilient and continuously adapting to changing environments by transitioning to alternative stable states.
Managing wilding pines in the Cape Floristic Region, South Africa : progress and prospects
(Elsevier, 2025-02) Martin, Grant D.; Canavan, Kim; Chikowore, Gerald; Bugan, Richard; De Lange, Willem; Du Toit, Ben; Harding, Graham; Heath, Ronald; Hill, Martin; Hurley, Brett Phillip; Ivey, Philip; Muir, Debbie; Musedeli, Jufter; Richardson, David M.; Slippers, Bernard; Stafford, Louise; Turner, Andrew; Watson, Kirsten; Van Wilgen, Brian W.
The occurrence and continuing spread of wilding pines (genus Pinus) in the Cape Floristic Region (CFR), South Africa, impacts negatively on water resources, threatens the region's rich biodiversity, and increases the damage caused by uncontrolled wildfires. The invasive potential and threat of wilding pines has been regularly reported since the 1940s, leading to the development and implementation of various control strategies. The last substantial review of pine invasions and their management in the CFR (in 2012) recommended several actions, including securing more sustainable funding and adopting alternative control methods. We review the last 12 years of wilding pine research and management in the CFR, and provide updates on spread and impact, government funding, payments for ecosystems services initiatives, and contributions of the South African Forest industry. We note an increase in private funding, specifically to address invasion in priority catchment areas in the Greater Cape Town region, as well as a recent decline in government funding. Steps have also been taken to revive research aimed at biological control of pines originating from the Iberian Peninsula. The forest industry has deployed species with lower fecundity in some parts of the CFR and has also started experimenting with hybrids that could potentially be less invasive. New methods for applying herbicides may prove to be more efficient than currently used methods. We discuss five opportunities for addressing current shortcomings in the management of wilding pines, namely broadening sources of funding to increase sustainability, effectively integrating all available management techniques, accommodating the need for commercial forestry, focussing scarce funds on priority areas, and raising awareness. We stress that failure to contain rampant invasions by wilding pines will have far-reaching consequences for conservation in the CFR.
An integrative re-evaluation of the Fusarium sambucinum species complex
(Westerdijk Fungal Biodiversity Institute, 2025-03) Sandoval-Denis, M.; Costa, M.M.; Broders, K.; Becker, Y.; Maier, W.; Yurkov, A.; Kermode, A.; Buddie, A.G.; Ryan, M.J.; Schumacher, R.K.; Groenewald, J.Z.; Crous, Pedro W.
The species-rich Fusarium sambucinum species complex (FSAMSC; Fusarium, Nectriaceae, Hypocreales) is well-known for including devastating plant pathogens and toxigenic species. However, this group of grass-loving fungi also accommodates soil saprobes, endophytes, mycoparasites and rare opportunistic pathogens of humans and other animals. Recent publications have highlighted the vast phylogenetic and biochemical diversity of the FSAMSC, although a large number of taxa in FSAMSC have not been systematically described and still lack Latin binomials. In this study we established the phylogenetic breadth of the FSAMSC using an integrative approach including morphological, multilocus phylogenetic, and coalescence analyses based on five gene regions (calmodulin, RNA polymerase II largest and second largest subunits, translation elongation factor 1-α, and β-tubulin). Results obtained support the recognition of 75 taxa in FSAMSC, including all the currently known species segregates of the Fusarium head-blight pathogen F. graminearum s. lat. Thirty novel species are formally described and illustrated, while four phylogenetic species remain undescribed. An epitype is proposed for the generic type of Fusarium, F. sambucinum, from recently collected material identified by means of morphology, phylogenetics and mating experiments, fixing the phylogenetic application of the name. Additional notes are included on the typification of Fusisporium cerealis (syn. Fusarium cerealis).
Central nervous system infection by free-living nematode Cephalobus cubaensis in a human host in Africa
(MDPI, 2025-02) Sriruttan-Nel, Charlotte; Cairns, Chelline; Boughan, Shareen; Moodley, Bhavani; Sun, Lisa Ming; Chan, Wai Yin; Ismail, Arshad; Mwazha, Absalom; Bennimahadeo, Praniel; Manickchund, Nithendra; Moyo, Mthabisi; Nkwanyana, Thabani; Msimang, Mpumelelo Z.; Essa, Ahmed; Frean, John; Moosa, Mahomed-Yunus
BACKGROUND : Human central nervous system infections due to free-living nematodes, although extremely rare, are usually fatal. Immunodeficiency has not been a feature of most of these cases, unlike the situation pertaining to disseminated Strongyloides stercoralis infection. CASE REPORT : An elderly immunocompetent man presented with a history of tinnitus and otalgia, progressing to central nervous system involvement with confusion, weakness, and other neurological signs. Examination revealed a unilateral external auditory canal soft tissue mass and radiological evidence of ipsilateral temporal bone destruction and brain parenchymal disease. A biopsy of the ear canal mass revealed the presence of an unidentified nematode species, and treatment with anthelminthics was started. The patient’s clinical condition deteriorated and he died shortly after admission to the intensive care unit. The immediate cause of death was bronchopneumonia. During the autopsy, an extensive involvement of the right middle cranial fossa was found, with destruction of the squamous and petrous parts of the temporal bone. RESULTS : We identified adult, larval, and egg stages of a free-living nematode in the antemortem external auditory canal tissue mass and the post-mortem brain samples. Polymerase chain reaction assays, with Sanger and whole-genome sequencing, identified Cephalobus cubaensis. This is a free-living species not previously known to be pathogenic to humans, although nematodes of the same genus have caused mastitis in horses. CONCLUSIONS : Microscopic appearance and the invasive behaviour of the pathogen evoked a putative diagnosis of Halicephalobus gingivalis, the most frequently reported free-living nematode infecting humans. However, this nematode’s size and anatomical features, and the clinical presentation and duration of illness, prompted the consideration of an alternative species. We speculate that an initial bacterial otitis externa provided the opportunity for colonization by the nematode from an environmental source and subsequent invasion.
The role of pheromones and temporal mechanisms in the reproductive isolation of Monochamus maculosus, Monochamus notatus, and Monochamus scutellatus (Coleoptera: Cerambycidae)
(Oxford University Press, 2025) Andrade, Samara M.M.; Mctavish, Michael J.; Smith, Sandy M.; Allison, Jeremy D.
The mechanisms used to facilitate mate location among insects—such as pheromones—can inhibit interspecific attraction and confer reproductive isolation. However, pheromone components seem conserved within the genus Monochamus (Coleoptera: Cerambycidae) with the compound 2-(undecyloxy)ethanol (referred to as monochamol) being identified as the sex-aggregation pheromone or putative pheromone attractant for at least 15 species in this genus. This pheromone parsimony suggests the existence of additional isolating mechanisms. Here we describe the results of laboratory and field assays of additional mechanisms, including laboratory volatile collections and field trapping experiments that assessed the potential presence of additional pheromone components, diel rhythms of pheromone production, and phenological/diel flight activity in the reproductive isolation of sympatric populations of three species of Monochamus in the Great Lakes Forest Region of Ontario, Canada. Chemical analyses of volatile extractions indicate that monochamol is produced by male Monochamus maculosus and Monochamus scutellatus, but no qualitative differences were observed in male extracts of these two species suggesting that there are no additional pheromone components that confer specificity. No quantitative differences were found in the production of monochamol by male M. scutellatus during the photophase and scotophase suggesting there is no diel rhythm in pheromone production. Our results indicate that M. scutellatus flies earlier in the season and day than M. maculosus and Monochamus notatus, which could partially contribute to their reproductive isolation. Overall, no obvious differences in pheromone composition were observed but minor differences in flight times were observed, suggesting other isolating mechanisms may exist.

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