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

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Smallholder farmers’ knowledge, perception and management of Spodoptera frugiperda (Lepidoptera: Noctuidae) on Zea mays at irrigation schemes in Limpopo province, South Africa
Nethononda, Phophi D.; Hurley, Brett Phillip; Slippers, Bernard; Makhura, Moraka Nakedi (Elsevier, 2026-03)
The fall armyworm (Spodoptera frugiperda) was first detected in Limpopo province, South Africa, during the 2016/2017 cropping season and continues to cause significant damage to maize production in the region. Despite the significant damage caused by S. frugiperda to maize, there is a lack of documented information on smallholder farmers' responses and control practices in South Africa. This study investigated smallholder farmers' knowledge, perceptions, and management practices of S. frugiperda at the Dzindi and the Tshiombo irrigation schemes in Limpopo province, South Africa. In this study, an irrigation scheme refers to a communal water distribution system that channels water from a river to multiple plots under smallholder cultivation through furrows or canals. Data were collected through 16 focus group discussions with farmers from the two irrigation schemes. A total of 118 farmers participated in the interviews. Each was assigned a unique identifier, which allowed for the recording and analysis of individual responses where applicable. Thematic analysis was used to identify and summarize common themes from participants’ responses, while descriptive analysis using frequencies and percentages was employed to present the responses quantitively. Farmers perceived S. frugiperda as the most destructive insect pest, yet lacked knowledge of its biology, being unable to identify its eggs, pupae, or adult moths. Control was largely through insecticide use. At the Dzindi irrigation scheme, farmers adopted Bt maize but did not comply with resistance management practices. The findings underscore the urgent need for farmer education on insect biology, responsible pesticide use, and proper implementation of Bt maize. The study also highlights the importance of collective rather than individual efforts in managing S. frugiperda, as the consequences of mismanagement can affect all farmers. These findings reveal major gaps in Integrated Pest Management (IPM) practices among smallholder farmers in Limpopo province, South Africa. HIGHLIGHTS • First detection of Spodoptera frugiperda in Limpopo Province, South Africa, occurred during the 2016/2017 cropping season. • Smallholder farmers lack knowledge of the pest's biology, relying on insecticides for its management. • Concurrent use of insecticides and Bt maize raises concerns over the potential evolution of S. frugiperda resistance in the region.
Diversification of an emerging bacterial plant pathogen; insights into the global spread of Xanthomonas euvesicatoria pv. perforans
Timilsina, Sujan; Iruegas-Bocardo, Fernanda; Jibrin, Mustafa O.; Sharma, Anuj; Subedi, Aastha; Kaur, Amandeep; Minsavage, Gerald V.; Huguet-Tapia, Jose C.; Klein-Gordon, Jeannie; Adhikari, Pragya; Adhikari, Tika B.; Cirvilleri, Gabriella; Tapia de la Barrera, Laura Belen; Bernal, Eduardo; Creswell, Tom C.; Doan, Tien Thi Kieu; Coutinho, Teresa A.; Egel, Daniel S.; Félix-Gastélum, Rubén; Francis, David M.; Kebede, Misrak; Ivey, Melanie Lewis; Louws, Frank J.; Luo, Laixin; Maynard, Elizabeth T.; Miller, Sally A.; Nguyen, Nga Thi Thu; Osdaghi, Ebrahim; Quezado-Duval, Alice M.; Roach, Rebecca; Rotondo, Francesca; Ruhl, Gail E.; Shutt, Vou M.; Thummabenjapone, Petcharat; Trueman, Cheryl; Roberts, Pamela D.; Jones, Jeffrey B.; Vallad, Gary E.; Goss, Erica M. (Public Library of Science, 2025-04-09)
Emerging and re-emerging plant diseases continue to present multifarious threats to global food security. Considerable recent efforts are therefore being channeled towards understanding the nature of pathogen emergence, their spread and evolution. Xanthomonas euvesicatoria pv. perforans (Xep), one of the causal agents of bacterial spot of tomato, rapidly emerged and displaced other bacterial spot xanthomonads in many tomato production regions around the world. In less than three decades, it has become a dominant xanthomonad pathogen in tomato production systems across the world and presents a compelling example for understanding diversification of recently emerged bacterial plant pathogens. Although Xep has been continuously monitored in Florida since its discovery, the global population structure and evolution at the genome-scale is yet to be fully explored. The objectives of this work were to determine genetic diversity globally to ascertain if different tomato production regions contain genetically distinct Xep populations, to examine genetic relatedness of strains collected in tomato seed production areas in East Asia and other production regions, and to evaluate variation in type III secretion effectors, which are critical pathogenicity and virulence factors, in relationship to population structure. We used genome data from 270 strains from 13 countries for phylogenetic analysis and characterization of type III effector gene diversity among strains. Our results showed notable genetic diversity in the pathogen. We found genetically similar strains in distant tomato production regions, including seed production regions, and diversification over the past 100 years, which is consistent with intercontinental dissemination of the pathogen in hybrid tomato production chains. Evolution of the Xep pangenome, including the acquisition and loss of type III secreted effectors, is apparent within and among phylogenetic lineages. The apparent long-distance movement of the pathogen, together with variants that may not yet be widely distributed, poses risks of emergence of new variants in tomato production.
Decoding Cryptococcus : from African biodiversity to worldwide prevalence
Coelho, Marco A.; David-Palma, Ma´rcia; Aylward, Janneke; Pham, Nam Q.; Visagie, Cobus M.; Fuchs, Taygen; Yilmaz, Neriman; Roets, Francois; Sun, Sheng; Taylor, John W.; Wingfield, Brenda D.; Fisher, Matthew C.; Wingfield, Michael J.; Heitman, Joseph (Public Library of Science, 2025-02-03)
Fungal pathogens cause millions of infections and deaths annually, while also contributing to global food insecurity [1]. Among them, basidiomycete Cryptococcus species—particularly C. neoformans (Cn; previously C. neoformans var. grubii, serotype A; lineages VNI, VNII, VNBI, and VNBII), C. deneoformans (Cd; previously C. neoformans var. neoformans, serotype D; lineage VNIV), and the C. gattii (Cg) species complex (Fig 1A)—are significant opportunistic and primary pathogens, especially in sub-Saharan Africa [2,3]. These pathogens primarily cause cryptococcosis, manifesting as severe pulmonary infections or life-threatening meningoencephalitis in both immunocompromised and apparently immunocompetent individuals. Exposures are typically thought to occur by inhalation of desiccated yeast cells or spores from the environment [4]. While Cryptococcus species vary in their occurrence worldwide, mounting evidence suggests an evolutionary origin in Africa for most of the pathogenic Cryptococcus species, where they occupy diverse ecological niches such as trees, pigeon guano, and mammalian middens (Fig 1B). While Cn, Cd, and Cg are pathogenic, nonpathogenic species within the genus (such as C. amylolentus, C. wingfieldii, and C. floricola; Fig 1A) occur either as African microendemic species or are known thus far from only a single isolate in the Canary Islands (C. floricola) [5,6]. This review explores the likely African origins of Cryptococcus, its ecological diversity, and how pathogenic species spread globally, transitioning from environmental microbes to human pathogens.
Prostephanus truncatus outcompetes Sitophilus zeamais under varying temperatures and introduction sequence on stored maize grain
Mlambo, Shaw; Mvumi, Brighton M.; Machekano, Honest; Nyamukondiwa, Casper (Elsevier, 2026-01)
Coexistence of insect pests can result in facultative or antagonistic interactions. For sympatric pest species, explaining coexistence is crucial for understanding their combined impact, resource competition, and may inform management strategies. Prostephanus truncatus and Sitophilus zeamais commonly coexist as primary colonisers in stored maize grain. To determine how these species interact, two experiments mimicking competition scenarios on stored grain were conducted at 25, 30 and 35 °C (65 % RH). In Experiment 1, P. truncatus and S. zeamais were introduced simultaneously (interspecific) and in singular (intraspecific) populations at low (20), medium (40), and high (80) parental densities. In Experiment 2, we used similar temperatures and parental densities. However, one species was introduced 10 days after the other, and vice versa. Mini-polypropylene bags, each loaded with 65 ± 5g of dried orange maize grain, were used for both experiments. Progeny production, grain damage, grain weight loss, insect feeding dust and holes on bags bored by beetles, were recorded after 65 days of storage. Results showed that (i) P. truncatus outcompeted S. zeamais in interspecific interactions at 25 and 30 °C across parental densities, (ii) both species’ ecological performances were suppressed at 35 °C, (iii) P. truncatus caused higher grain damage regardless of the introduction sequence with S. zeamais and (iv) P. truncatus dispersed by tunnelling through polypropylene bags to avoid competition. Understanding interactions among sympatric pest species is essential for accurately predicting infestation outcomes and developing effective pest management under increasingly warming environments. HIGHLIGHTS • P. truncatus outcompeted S. zeamais across different temperatures and parental densities. • Ecological performance was suppressed at 35 °C for both P. truncatus and S. zeamais. • Sequence of introduction did not reduce P. truncatus competitive advantage over S. zeamais. • Tunneling was competition-induced and could trigger P. truncatus dispersal.
Assessing Gonipterus defoliation levels using multispectral unmanned aerial vehicle (UAV) data in Eucalyptus plantations
Nzuza, Phumlani; Schröder, Michelle L.; Heim, Rene J.; Daniels, Louis; Slippers, Bernard; Hurley, Brett Phillip; Germishuizen, IIaria; Sivparsad, Benice; Roux, Jolanda; Maes, Wouter H. (Elsevier, 2025-12)
Invasive insect pest Gonipterus sp. n. 2 (Coleoptera: Curculionidae) threatens Eucalyptus species, causing defoliation and yield loss through adult and larval feeding. Early detection is important for early intervention to prevent pest outbreaks. As conventional insect pest monitoring methods are time-consuming and spatially restrictive, this study assessed the potential of UAV monitoring. Multispectral imagery was obtained with Unmanned Aerial Vehicles (UAVs) across six different stands of young Eucalyptus dunnii with varying levels of Gonipterus sp. n. 2 infestations. Some stands were revisited, a total of 9 datasets were covered. Reference damage levels were obtained through visual assessments of (n = 89–100) trees at each site. Across sites, a decrease in canopy reflectance in both the visual and the near-infrared domains with increasing damage levels was consistently observed. Several vegetation indices showed consistent patterns, but none showed site independence. XGBoost, Support Vector Machine and Random Forest (RF) were used to predict damage levels using five input spectral data types. XGBoost performed best, closely followed by RF. Both models consistently selected very similar features. The best-performing models included reflectance, vegetation indices and grey-level co-occurrence matrix data. When data from 10 different wavelengths were used, the highest classification accuracy was 92 % across all sites in classifying defoliation levels. With a classical 5-band multispectral camera, accuracy was 88 %, but distinguishing medium damage from low remained challenging. However, the method was less reliable when trained and validated on separate fields. This study highlights the potential of multi-site datasets in increasing the model's generalization, using UAV based multispectral imagery to assess Gonipterus sp. n. 2 damage and demonstrating reliable upscaling from individual tree assessments to stand scale. However, it also recognises the difficulty of generating a robust model that performs well on untrained sites. HIGHLIGHTS • Canopy damage from Gonipterus sp. n. 2 was assessed across stands using UAV imagery, capturing defoliation, chlorophyll reduction. • The 5-band imagery perfomed comparable to the 10-band but was less effective at detecting subtle low vs no damage defoliation. • Similar pattern was observed across sites but absolute reflectance and vegetation indices are site specific.
Enhancing plantation forest sustainability : a review of Eucalyptus defence mechanisms to foliar fungal pathogens
Solis, Myriam; Hammerbacher, Almuth; Wingfield, Michael J.; Naidoo, Saloshnee (Springer, 2025-02)
PURPOSE OF THE REVIEW : In this review, we synthesize knowledge generated over many decades on the main defence responses of Eucalyptus to fungal leaf pathogens with the aim of identifying targets for breeding disease tolerant trees. We highlight physiological and molecular traits associated with host defence in relation to pathogen life-style. Overall, the purpose of this review is to identify resistance mechanisms that offer improved resilience of Eucalyptus plantations in the face of increasing threats by foliar fungal pathogens. The broad aim is to promote sustainable forestry through appropriate selection of resistance traits in trees that are widely planted for commercial timber production. RECENT FINDINGS : Eucalyptus is among the most important tree genera planted for commercial timber production worldwide. Numerous foliar pathogens have been reported on these trees in the last 30 years with numbers of recent reports increasing exponentially. The majority of these diseases affect the leaves and shoots of the trees. Knowledge on resistance traits in Eucalyptus to fungal foliar pathogens is limited. This is in part due to the high intra- and inter-species variation in molecular and physiological responses of the host and variation in responses to different pathogens, especially those with different trophic modes. A well-founded understanding of such host responses will provide valuable knowledge required to maintain healthy, sustainable Eucalyptus plantations, especially in the face of changing environmental conditions, where new diseases are caused by fungi previously not considered relevant. SUMMARY : Foliar diseases are among the most important challenges for Eucalyptus plantations globally. The effects of climate change and new or more serious outbreaks present an important threat to the sustainability of Eucalyptus plantations worldwide. Due to restrictions on the use of chemicals, more feasible solutions for disease management lie in selecting planting material with resistance traits. To achieve that goal, it is essential to understand the most important physiological and molecular responses of Eucalyptus to infection by pathogens that infect their foliar tissues. In this review we summarise the available knowledge of the main physiological defence barriers and genetic traits that play key roles in the broad defence against foliar fungal pathogens. Furthermore, we consider defence pathways that are specifically related to the lifestyle and trophic mode of the pathogens. In order to ensure the future sustainability of Eucalyptus plantations, it will be necessary to understand how disease resistance is affected by climate change, as well as the adaptability of the hosts and pathogens to newly emerging environmental conditions.
The pine pathogen Diplodia sapinea : expanding frontiers
Wingfield, Michael J.; Slippers, Bernard; Barnes, Irene; Duong, Tuan A.; Wingfield, Brenda D. (Springer, 2025)
PURPOSE OF REVIEW : This review offers a thorough examination of the pine pathogen Diplodia sapinea, tracing its historical significance from its initial impact on South African non-native Pinus plantations to its recent emergence as a major threat to forests, particularly in Europe. It also highlights recent findings regarding its taxonomic position, genetic studies, and shifts from being perceived as a wound-infecting pathogen to an endophyte in healthy Pinus species that causes disease after stress. RECENT FINDINGS : Recent years have witnessed a dramatic increase in the damage caused by D. sapinea in natural and planted forests. This escalation is apparently strongly linked to climate change. The pathogen’s previously confused taxonomic position has been clearly resolved in the Botryosphaeriaceae, alongside several sibling species. Diplodia sapinea is now well-understood as an endophyte in healthy trees, which has significant implications for studies aimed at understanding its biology. Importantly, robust techniques including those utilizing genome sequences, are now available for rapid identification and population genetic studies of the pathogen and the factors that drive disease outbreaks. SUMMARY : Over the past century, D. sapinea has transitioned from a localized problem in South African non-native plantations to a global threat to both natural and planted forests, particularly in Europe. This review underscores the importance of historical context in understanding the evolution of the pathogen’s impact. It also lays the foundation for future research endeavours, leveraging modern technologies to address key questions surrounding its biology and ecology.
Extracting protoplasts from filamentous fungi using extralyse, an enzyme used in the wine industry
Wilson, Andi M.; Van Dijk, Alida; Marx, Bianke; Du Plessis, Deanne; Terblanche, Grant; Bornman, Simoné; Wilken, Pieter Markus; Duong, Tuan A.; De Fine Licht, Henrik H.; Wingfield, Brenda D. (Wiley, 2025-03)
The ability to extract protoplasts has contributed significantly to the study of fungi and plants. Protoplasts have historically been used to determine chromosome number via pulsed-field electrophoresis and for the functional characterization of genes via protoplast transformation. More recently, protoplasts have been used to extract the high-molecular-weight DNA required for long-read sequencing projects. The availability of efficient protoplast extraction protocols is thus integral to the study and experimental manipulation of model and non-model fungi. One major hurdle to the development of such protocols has been the discontinuation of enzymes and enzyme cocktails used to digest the fungal cell wall. Here, we provide five protoplast extraction protocols for use in various filamentous ascomycete species spanning the genera Ceratocystis, Fusarium, Metarhizium, Ophiostoma, and Sclerotinia. These protocols all use an inexpensive, readily available enzyme cocktail called Extralyse, a commercially available product commonly used in the wine making industry. Using this enzyme cocktail overcomes reliance on the laboratory-grade enzymes that have frequently been discontinued and are often cost prohibitive at the concentrations required. The protocols described here will allow further research, including genome editing, to be conducted in these fungal genera. Importantly, these protocols also provide a starting point for the development of protoplast extraction techniques in other filamentous fungi. This resource can therefore be used to expand the molecular toolkits available for fungi beyond the species described here, including those with relevance in both medical and biotechnological industries. Basic Protocol 1: Protoplast extractions from Ceratocystis eucalypticola and Ceratocystis fimbriata. Basic Protocol 2: Protoplast extractions from Fusarium circinatum. Basic Protocol 3: Protoplast extractions from Metarhizium acridum, Metarhizium brunneum, and Metarhizium guizhouense. Basic Protocol 4: Protoplast extractions from Ophiostoma novo-ulmi. Basic Protocol 5: Protoplast extractions from Sclerotinia sclerotiorum.
Responses of fruit flies (Diptera: Tephritidae) to protein bait : effects of tree canopy, species, physiological state and weather
Ramaoka, Msizi Ronald; Manrakhan, Aruna; Weldon, Christopher W. (Elsevier, 2025-11)
The application of protein baits forms the core of fruit fly (Diptera: Tephritidae) control measures in many orchard environments. Protein baits target adult fruit flies, which need protein for reproductive maturation. A proper understanding of the factors influencing fruit fly responses to protein is required to optimise control outcomes. In this study, responses to protein bait by three fruit fly species, Ceratitis capitata (Wiedemann), C. cosyra (Walker), and Bactrocera dorsalis (Hendel), were investigated. This was done in two field cages erected over lemon trees within an orchard. The response of each species to protein bait presented as a station and positioned at different heights within the tree canopy was evaluated. For each species, effects of fly age, sex, and nutritional status were evaluated under conditions of varying temperature and relative humidity. The highest response occurred when protein baits were placed in the middle to upper tree canopy. Species, nutritional status, sex and age also affected protein foraging. Ceratitis capitata responded more to bait compared to B. dorsalis and C. cosyra. The lowest response to protein bait was by one-day-old protein fed flies, while 10-day-old protein-deprived flies were most responsive. Protein deprived females were more attracted to protein than males fed the same diet. Flies responded to bait when temperatures were between 20 and 30 °C. Based on the results, the success of protein baits in controlling fruit flies in a tree canopy is height dependent and can be lower in areas with alternative protein sources.
Short communication: Elevated testosterone correlates with enhanced innate immune function in a cooperatively breeding rodent
Wallace, Kyra Mary Elizabeth; Venter, S.N. (Stephanus Nicolaas); Bennett, Nigel Charles; Hart, Daniel William (Elsevier, 2025-10)
In many vertebrates, elevated testosterone is believed to compromise the immune function, reflecting a trade-off between reproduction and survival. However, such trade-offs may potentially be relaxed in cooperative breeders, where social conflict and sexual selection are reduced. We investigated the relationship between testosterone, cortisol, and innate immunity in captive male Damaraland mole-rats (Fukomys damarensis), a eusocial rodent with minimal aggression-driven reproductive competition. Using microbial killing assays (MKAs) and white blood cell counts as proxies of immune function, we found that urinary testosterone concentration was positively correlated with immune strength. Males with higher urinary testosterone concentrations exhibited significantly greater antimicrobial capacity and elevated total white blood cell counts. However, urinary testosterone was unrelated to independent immune cell differentials. While, reproductive status, age, body mass, and urinary cortisol concentrations had a limited effect on any immune metric. These findings, while correlative, challenge traditional endocrine-immune trade-off models and infer that, in this species, testosterone may signal condition rather than impose immunosuppressive costs.
Myco-ecological warfare with Meloidogyne species
Ramatsitsi, Ndivhuwo; Manyevere, Alen; Motloba, Tuelo (Taylor and Francis, 2025)
Root-knot nematodes (RKNs), Meloidogyne, are the most widely distributed plant-parasitic nematodes. This group of soil-borne pests represents one of the largest causes of plant biotic stress that are challenging to manage, deeming them economically important. Using fungal bio-control agents (BCAs) is considered economic and ecologically friendly. This review illuminates how fungal BCAs generally decrease the negative impacts of RKNs, i.e. either via antagonistic activities or by modifying effects on plant root morphology and physiology. Of the 38 reviewed BCAs, the most studied were Arthrobotrys, Aspergillus, Lecanicillium, Purpureocillium, Trichoderma, Pochonia and Fusarium endophytes. Of the several studied fungal BCAs, approximately 10 are globally marketed. Based on literature, an understanding of the intricate interactions between fungal BCAs and Meloidogyne is a prerequisite for carrying out an appropriate method for formulation of bio-control products. The major challenge in commercialising fungal BCAs has been attributed to inconsistency concerns under different conditions, incompatibilities of BCAs species and formulation procedures that result in reduced effectiveness.
Phosphite inhibits Phytophthora cinnamomi by downregulating oxidoreductases and disrupting energy metabolism
Prabhu, Sreedhara Ashok; Naicker, Previn; Duong, Tuan A.; Govender, Ireshyn Selvan; Engelbrecht, Juanita; Backer, Robert; Stoychev, Stoyan Hristov; Van den Berg, Noelani (Frontiers Media, 2025-08-25)
Phytophthora root rot caused by the hemibiotrophic oomycete, Phytophthora cinnamomi is a major biotic hindrance in meeting the ever-increasing demand for avocados. In addition, the pathogen is a global menace to agriculture, horticulture and forestry. Phosphite trunk injections and foliar sprays remain the most effective chemical management strategy used in commercial avocado orchards against the pathogen. Phosphite is known to counter P. cinnamomi both directly and indirectly through fortification of host defense. However, phosphite's direct mode of action is still not understood completely. This study identified a P. cinnamomi isolate GKB4 sensitive to phosphite (EC50 of 27.9 μg/mL) and investigated the direct impact of phosphite on this isolate through label-free quantitative SWATH-MS. Proteomics data analysis of untreated vs. phosphite-treated samples revealed that the xenobiotic affects the pathogen's growth by targeting the oxidoreductases whose abundance is significantly reduced. Further, perturbations in the energy metabolism and membrane/transmembrane proteins and transporters, and oxidative stress contribute to growth inhibition. The current study also identified increased putrescine biosynthesis, a polyamine, that when present at non-optimal concentrations could be cytostatic/cytotoxic. The differential expression of enzymes involved in the biosynthesis of secondary metabolites and the intermediates/precursors involved in their biosynthesis is an interesting finding that needs further investigation to ascertain their role in phosphite-induced stress. The pathogen's attempt to counter phosphite's growth-inhibitory effects—through upregulation of alternate bioenergetics pathways (amino acid catabolism and β-oxidation of fatty acids), mitochondrial translation and translocation machinery, peroxisomal proteins, and antioxidants—appears ineffective. This research furthers our limited understanding of the direct in vitro effects of phosphite on P. cinnamomi and has identified potential candidates for molecular functional investigation. HIGHLIGHTS • A phosphite-sensitive P. cinnamomi isolate (PcGKB4) was identified. • Label-free quantitative proteomics identified that phosphite inhibits PcGKB4 predominantly by downregulating oxidoreductases and glycolysis. • Phosphite increased the biosynthesis of putrescine. Depending on its intracellular levels it could promote growth or act as a cytostatic/cytotoxic agent. • Enhanced production of proteins involved in alternative energy metabolism, mitochondrial translation, peroxisomal proteins and antioxidants is a futile countereffort by the pathogen to revive growth.
Estimation of breed composition of South African sheep affected with wet carcass syndrome
Kooverjee, Bhaveni B.; Van der Nest, Magrieta Aletta; MacNeil, Michael D.; Scholtz, Michiel M.; Neser, Frederick W.C.; Soma, Pranisha (Frontiers Media, 2025-07-21)
Wet carcass syndrome (WCS), a condition that negatively affects the quality of carcasses after slaughter, is seriously threatening the South African sheep industry. Despite its economic impact, the underlying genetic mechanisms of WCS remain unknown. Initially, WCS was predominantly observed in Dorper sheep, leading to speculation that the condition was breed-specific. However, recent reports indicate WCS has occurred in various sheep breeds. This study aimed to determine whether WCS is breed-specific and whether breed composition influences its incidence. Meat samples from 164 WCS-affected and 83 unaffected sheep were collected and genotyped using the Ovine 50K SNP Bead Chip. Principal Component Analysis (PCA) and ancestry matrix assessments revealed that WCS-affected and unaffected sheep belonged to different commercial breeds. Additionally, crossbred animals were affected. These findings suggest that WCS is strongly associated with breed and that Dorper and Merino-types show heightened susceptibility. The genetic diversity of the affected animals suggests a multifactorial etiology, potentially involving environmental and managerial factors. Future studies should also explore the physiological mechanisms underlying WCS, including metabolic and stress-related pathways, to develop effective prevention strategies.
Determinants of mating success in a lek-mating species
Queffelec, Josephine; Allison, Jeremy D.; Slippers, Bernard; Greeff, Jacobus Maree (Wiley, 2025-11)
• Leks are male-biased aggregations formed for mating, where sperm is the only resource acquired by visiting females. • One of the many advantages of leks is the possibility to efficiently assess the quality of potential mates by comparing aggregated individuals of the same sex with one another. • When direct mate choice occurs in a lekking species, it is often exhibited by females, but some studies have also demonstrated the presence of male mate choice. • We investigate mate choice in the lek-forming European woodwasp, Sirex noctilio. • We determine the importance of age and size as predictors of mating success. • We demonstrate that mating is not random and that male and female traits affect mating success. • Age plays an important role in mating success in both males and females, with older males mating more and younger females being more attractive and more receptive to mating. • Relative male size seems to play a role in mating success, with males being more successful when attempting to mate with females that are larger than they are.
Bark and ambrosia beetle communities (Coleoptera: Curculionidae: Scolytinae: Platypodinae) across five mangrove forests in South Africa
Osorio, Jhon Alexander; Chara, Jenny (SpringerOpen, 2025-06)
BACKGROUND : Mangrove forests are of fundamental significance that support a diverse array of species, but despite their importance and the benefits they provide, the health of these trees is under constant threat. This is due to a variety of environmental and human factors, which lead to their weakening and susceptibility to colonization by insect pests. Although the diversity of bark and ambrosia beetles has been well documented worldwide, there is limited information available regarding their relationships with mangroves. To investigate the diversity and distribution of ambrosia and bark beetles associated with mangrove habitats in South Africa, extensive field surveys and species sampling across various mangrove sites were carried out, as well as Lindgren and Panel traps were installed along five estuaries in KwaZulu–Natal and one in the Eastern Cape Province, from October to December 2013 and January to February 2014. RESULTS : A total of 8677 individuals comprising 11 genera and 16 species of ambrosia and bark beetles were captured. Of these, the most abundant was Hypothenemus eruditus (n = 2178; 25.10%), followed by Ambrosiodmus natalensis (n = 863; 10.36%), Xyleborus affinis (n = 844; 9,73%) and Premnobius cavipennis (n = 833; 9,60%), respectively. The remaining species registered an incidence lower than 7%. From the analysis of representativeness by rarefaction curves, there was no trend toward an increase in species as the number of trajectories increased. CONCLUSIONS : This research contributes to understanding the biodiversity of ambrosia and bark beetle assemblages within South African mangrove ecosystems and underscores the importance of conserving these habitats in the face of environmental and anthropogenic pressures. The findings provide a valuable baseline for future studies and management strategies aimed at preserving mangrove health and monitoring beetle community dynamics in these critical coastal environments.
BISMiS Live : a digital platform for global communication among microbial systematists
Jangid, Kamlesh; Li, Wen-Jun; Venter, S.N. (Stephanus Nicolaas); Teo, Wee Fei Aaron; Whitman, William (Elsevier, 2025-09)
BISMiS Live, launched on March 20, 2021, emerged as a timely response to the disruption caused by the CoViD-19 pandemic, offering a global virtual platform for discourse in microbial systematics. Spearheaded by the Bergey's International Society for Microbial Systematics (BISMiS), this monthly webinar series hosted renowned experts and engaged thousands of participants across 84 countries. The initiative emphasized inclusivity, scientific depth, and digital accessibility, with sessions archived on YouTube (@BISMiS_) for broader impact. Behind each event lies a dedicated team managing speaker coordination, technical execution, and global outreach. BISMiS Live has grown into an educational resource, integrated into university curricula and inspiring the next generation of microbial taxonomists. With suggestions for future innovation, such as student lightning talks, thematic series, and podcast formats, the platform is poised to evolve further. BISMiS Live stands as a digital bridge connecting systematists worldwide, sustaining knowledge exchange and community through innovation and collaboration. HIGHLIGHTS • BISMiS Live is a global webinar series on microbial systematics to promote inclusive, digital scientific exchange. • Run by volunteers, it is a key education/outreach tool with top experts and archived sessions on YouTube @BISMiS_. • Participants from 84 countries include students, postdocs, and faculty with diverse backgrounds and expertise. • Future plans include student talks, theme series, and a podcast format for broader impact.
Semiochemical-based strategies for sustainable management of the fall armyworm, Spodoptera frugiperda (J.E Smith) (Lepidoptera: Noctuidae)
Sisay, Birhanu; Nakamura, Akihiro; Mihretie, Aderajew; Tamiru, Amanuel; Weldon, Christopher William; Ashton, Louise A. (Springer, 2025-10)
Semiochemicals are produced by diverse taxa to mediate intra- and interspecific communication. These chemical cues are becoming increasingly important in integrated pest management (IPM) for manipulating key behaviors such as mating, foraging, and host selection in both plant–insect and insect-insect interactions. Semiochemical-based approaches regulate pest populations through techniques such as monitoring, mass trapping, and mating disruption. Understanding the chemical cues that mediate these interactions is crucial for developing sustainable and targeted pest management options. This review explores the role of semiochemicals in managing insect pests, with a focus on the fall armyworm (Spodoptera frugiperda), a globally significant pest native to the Americas. We discuss composition, variability, efficacy, specificity, and applications of plant volatiles and sex pheromones in pest management. Additionally, we address challenges associated with the adoption of semiochemical-based approaches and highlight emerging research directions to enhance their integration into IPM programs. By synthesizing current knowledge, this review underscores the potential of semiochemical-based strategies to reduce reliance on conventional insecticides while improving pest control efficiency. The strategic application of plant volatiles and sex pheromones in agricultural systems offers an opportunity to develop more ecologically sound and sustainable pest management practices, thereby fostering resilient cropping systems with minimal environmental impact.
Leaf area index-based phenotypic assessment of sweet potato varieties using UAV multispectral imagery and a hybrid retrieval approach
Tsele, Philemon; Ramoelo, Abel; Moleleki, Lucy Novungayo; Laurie, Sunette; Mphela, Whelma; Tshuma, Natasha (Elsevier, 2025-08)
Phenotyping based on the estimation of plant traits such as the leaf area index (LAI) could aid the identification and monitoring of the sweet potato health, growth status and gross primary productivity. Integrating radiative transfer models (RTMs), active learning algorithms and non-parametric regression methods using unmanned aerial vehicle (UAV) multispectral imagery have the potential for accurately estimating LAI across multiple crop varieties at varying growth stages. This study tested the boosted regression trees (BRT) and kernel ridge regression (KRR) for inversion of the PROSAIL RTM to retrieve LAI across 20 sweet potato varieties during peak growth stage. Furthermore, the study attempted to constrain the inversion process by using active learning (AL) techniques which ensured the selection of informative samples from a pool of RTM simulations. Results show that the most accurate LAI retrieval over the heterogeneous sweet potato canopy was achieved by integrating smaller PROSAIL simulations with the random sampling AL and KRR methods. The LAI retrieval accuracy had a coefficient of determination (R2) of 0.52, root mean squared error (RMSE) of 0.88 m2.m-2 and relative RMSE of 12.23 %. However, the BRT performance in-comparison to KRR, captured more spatial variability of observed LAI with a better prediction accuracy across the 20 sweet potato varieties. The hybrid approach developed in this study, show potential for accurate phenotyping of LAI dynamics across multiple sweet potato varieties during a matured growth stage. These findings have significant implications for sweet potato breeding programmes that are critical for developing new cultivars in South Africa.
Plant pathogen name game : Cross Kingdom Review for the naming of biotic agents associated with plants
Bull, Carolee T.; Salgado-Salazar, Catalina; Romberg, Megan K.; Allen, Cavan; Kantor, Mihail; Handoo, Zafar; Aboughanem-Sabanadzovic, Nina; Sabanadzovic, Sead; Coutinho, Teresa A. (Annual Reviews, 2025-09)
To communicate across scientific disciplines, regulatory bodies, and the agricultural community, the naming of plant pathogens assigned to specific taxa is critical. Here, we provide an overview of the nomenclatural systems governing the naming of plant-pathogenic nematodes, fungi, oomycetes, prokaryotes, and viruses. Although we focus on the nature of the nomenclatural codes, we briefly discuss fundamental principles of taxonomy, including classification and identification. Key elements of the codes of nomenclature that ensure stability and clarity when naming species of pathogens are defined. When comparing the practice of nomenclature across different kingdoms, the classification and nomenclatural systems differ, and thus unique challenges are faced. We provide guidance from the codes and current practice for naming novel species. When there are nomenclatural conflicts, international committees play a critical role in their resolution. They also play a role in updating the codes to reflect new advancements in science. With this review, we aim to assist plant pathologists, journal editors, and those in related fields by providing an entrée to the legalistic requirements of the codes. Authors must consult and follow the rules of the appropriate code for any proposal of new or new combinations of names. To those interested in naming new species (or renaming the current ones), we recommend collaborations with experts in the field of taxonomy to ensure that rules for accurate and consistent naming practices and procedures are followed and to increase the likelihood that the proposed nomenclature is correct and acceptable.
Cryphonectriaceae : biodiverse and threatening tree pathogens in the tropics and southern hemisphere
Wingfield, Michael J.; Pham, Nam Q.; Marincowitz, Seonju; Wingfield, Brenda D. (Annual Reviews, 2025-09)
The chestnut blight pathogen Cryphonectria parasitica is well-known for the devastation it caused to North American forests. It is less well recognized that numerous other fungi in the Cryphonectriaceae are emerging as threats to native and planted forests in the tropics and Southern Hemisphere. Unlike C. parasitica, these fungi, such as Chrysoporthe cubensis, initially gained attention due to a canker disease in plantations of non-native Eucalyptus. More than four decades of research have revealed a wide diversity of Cryphonectriaceae species that infect many other tree genera in the Myrtales. These fungi often exist as endophytes but become problematic when trees are planted outside their native range. Growing numbers of species are also undergoing host shifts from native to susceptible trees such as Eucalyptus, posing serious risks to both natural and planted forests. These fungi provide an example of the biodiversity of tree-infecting fungi that is understudied, despite their significant potential to harm forest ecosystems.

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