搜索结果：nematology

Insect collections offer a unique and practical way to enrich students' education at every level. Collecting insects and identifying specimens provides an active, hands-on activity that connects students to the natural world in a way that lectures alone cannot. With the advancement of technology, non-lethal approaches to traditional museum collections can still provide an experiential learning opportunity without the need for ethical considerations. This review emphasizes the significance of insect exposure in primary school, secondary school, undergraduate instruction, and public outreach settings, utilizing both traditional and contemporary methods. The goal at all levels is to share information about the diversity and uniqueness of insects while reducing the fear and stigma surrounding entomology. While traditional insect collections have justifiable applications, newly developed non-lethal methods are just as valid. Determining the most suitable methods for the target audience is crucial for the future of entomology. This article is part of the 2025 Collaborative Publication Program organized by the Entomological Society of America Student Affairs Committee to address emerging issues in Entomology.

Palm lethal yellowing phytoplasmas (PLYPs) are plant pathogens that cause fatal infections in various palm species in tropical regions. The only confirmed vector of these pathogens is Haplaxius crudus Van Duzee (Hemiptera: Cixiidae), a planthopper found in the Neotropics and parts of North America. The recent identification of a new PLYP in Madagascar, 'Candidatus Phytoplasma katsepyensis', was the impetus for vector studies. In 2024, an expedition was launched to document planthopper diversity on palms in Madagascar where phytoplasmas had previously been observed to identify putative vectors. Insect specimens belonging to the genus Nesomyndus were collected in relatively high abundance (n = 101) and later determined to represent three species: N. australis, N. maculatus and N. madagascarensis. Additionally, five coconut palms tested positive by qPCR for phytoplasma among the sites surveyed. Among all specimens of all three species, only nine out of 61 specimens of N. maculatus were positive for phytoplasma based on qPCR and high resolution melt curve analysis (HRMA) with four of these nine specimens having detectable levels of phytoplasma in the salivary glands by digital PCR. All positive specimens were collected from a single site. The detection of the phytoplasma in the salivary glands provides strong evidence that N. maculatus is a competent vector of a phytoplasma strain affecting coconuts in Madagascar. Future efforts will determine if the other species are also capable of acquiring the phytoplasma as well as evaluate critical details of the transmission cycle.

Over 80% of animal species rely on exoskeletal cuticle for body stabilization and protection from the environment, including predators, conspecifics, and pathogens. Therefore, the exoskeleton should be thick and robust; insects with thin cuticles are likely to be more vulnerable to injuries, desiccation, pathogens, and insecticides, and are less likely to survive attacks by predators. Aside from internal processes that influence cuticle deposition, environmental factors can have large effects on the rate and quantity of cuticle deposited during juvenile and adult stages. However, we currently lack a comprehensive understanding of the various environmental factors that shape cuticle development. We therefore provide an overview of the existing literature on key environmental factors including temperature, diet, and insecticides, that shape insect cuticle deposition and overall robustness. By synthesizing empirical evidence examining the relationship between these environmental factors and cuticle thickness, we identify broad, generalizable patterns across taxa and identify exciting, clear paths for future research.

Insecticides can greatly limit the impacts of cockroaches on indoor environment and human health. Insecticide resistance, however, reduces the efficacy of insecticides and increases insecticide use by both residents and pest control professionals. This study examined the relationship between insecticide cross-resistance and associated gene expression across nine different German cockroach populations from the eastern U.S. Using vial bioassays, we identified significantly correlated resistance between three insecticides from different classes (indoxacarb, lambda-cyhalothrin, fipronil), with potential cross-resistance between indoxacarb and lambda-cyhalothrin being the most strongly correlated. In gene expression studies, we found that cockroach cytochrome P450 expression was most strongly associated with apparent cross-resistance across populations, while microbial gene expression was more variable. These findings provide new insights on cross-resistance and associated mechanisms that can broadly impact resistance management in this important urban pest.

The development of eco-friendly pest management strategies is crucial for sustainable agriculture. In this study, we investigated the bioactivity of Solidago canadensis leaf extract against Meloidogyne incognita juveniles (J2). In vitro assays showed that aqueous extracts exhibited greater nematistatic (immobilizing) activity than less polar solvent extracts. Fractionation of the aqueous decoction extract using column chromatography yielded 11 fractions (F), which were evaluated at 100, 200, and 300 mg L- 1. The crude extract showed 100% nematistatic activity at all concentrations, while among the fractions, F5, F7, and F9 were the most effective. In the pot experiment, the crude extract and F7 reduced gall formation by 55.3%, whereas F8, despite low in vitro nematistatic activity (21.5%), achieved the highest gall reduction (58.7%). Unexpectedly, some fractions increased gall formation. GC-MS analysis of F7 and F8 revealed 20 phytochemical compounds, including several with reported nematode-suppressive properties. These findings underscore the potential of S. canadensis extracts and specific fractions as botanical nematistatic agents and emphasize the importance of combining the in vitro and pot bioassays when evaluating botanical nematicides.

Telenomus remus Nixon is an important egg parasitoid of the fall armyworm (Spodoptera frugiperda (J.E. Smith)), a major agricultural pest. Originally described in Malaysia in the 1920s, T. remus has since spread across the globe. Although it was released in Florida in the 1970s and 1980s, subsequent surveys suggested it had failed to establish in the state. However, its unexpected detection parasitizing fall armyworm egg masses in Florida in 2009 and 2013 suggested a reassessment of this species within the state was warranted. In this study, we set out fall armyworm sentinel egg masses across 10 counties in Florida to evaluate the current distribution of this parasitoid across the state. We compared cytochrome c oxidase subunit I gene barcodes from our survey to publicly available sequences representing T. remus populations from 24 countries spanning 4 continents and conducted phylogenetic analyses to examine the relationship of T. remus haplotypes with other Telenomus species. Our findings indicate that T. remus is now widely distributed across Florida, though it remains absent in the southeastern region of the state. We also identified 2 T. remus mitochondrial haplogroups, one that is globally distributed in Asia, South America, Africa, and Florida, and a second that was confined to the Eastern Mediterranean region (Israel, Egypt, and Lebanon) and East Africa (Kenya and Tanzania). Our phylogenetic analysis suggests these are 2 mitochondrial variants or strains of the same species, though additional studies are needed to further characterize the genetic variation between these 2 strains, as well as any important biological or ecological differences.

Effective management of cockroaches in multifamily housing presents a significant challenge. Despite the negative impacts of German cockroaches, Blattella germanica (L.) (Blattodea: Ectobiidae), on human health and well-being as well as data-based integrated pest management (IPM) solutions to cockroach problems, infestations continue to persist. Residents of multifamily housing, who are facing cockroach infestations, represent a critical insight into this gap in implementation of effective pest solutions. Thus, there is a need to understand what factors drive the lack of adoption of IPM for cockroach control in multifamily housing. A nationally distributed survey of renters living in multifamily housing with cockroaches was used to gauge resident experiences with and perceptions of cockroaches and cockroach control in their homes. The results of this survey (N = 926) reflected that a majority of respondents (i) had previously experienced cockroaches during childhood and were unbothered; (ii) associated cockroaches with negative impacts to human health; (iii) will either report cockroach problems to property management or do something about it themselves (eg, mechanical control, apply pesticide products, hire professional pest control); (iv) are mostly and equally satisfied with products they purchase and apply and professional pest control they hire (despite a noted continual presence of cockroaches in their homes). These findings establish a comprehensive dataset of perceptions of and experiences with cockroach infestations, which can be applied to developing more successful management strategies for German cockroaches in multifamily housing.

Sex-based disparities in disease burden and therapeutic response motivate efforts to prioritize women's health in drug development. We analyzed 195 drugs across 98 indications approved by the United States Food and Drug Administration (FDA) between 2015 and 2023 to assess whether industry focus and clinical trial enrollment reflect disease prevalence among males and females. Here, we show that therapies for female-predominant indications receive 1.5 times more approvals than male-predominant indications. Additionally, among trials leading to approval, female participation aligns with or exceeds disease prevalence in 67% of cases. Alignment is strongest in oncology, whereas cardiovascular and autoimmune diseases most often under-enroll women, with no improvement over time. We discuss that gains in female enrollment have plateaued and that further progress will require advances in diagnostics, greater use of objective endpoints, and improved tools to assess risks for women of reproductive potential.

The white-backed planthopper, Sogatella furcifera (Horváth, 1899), is a destructive rice pest that causes severe yield losses across Asia. Here, we manually curated a class of olfactory receptors: ionotropic receptors (IRs) genes using genomic and transcriptomic data, characterized tissue-specific expression profiles, and explored the functions of 3 IRco genes (SfurIR8a, SfurIR25a, SfurIR76b) via RNA interference (RNAi) and two-choice behavioral assays. We identified 14 IR genes and 3 IRco genes in S. furcifera, and the 3 IRco genes were predominantly expressed in the antennae of both sexes. qPCR verification confirmed that the expression of the 3 IRco genes was significantly downregulated after RNAi, with no obvious lethal effects on the nymphs. Behavioral assays showed that silencing any of the 3 IRco genes drastically impaired the host location ability of S. furcifera. Compared with the control, the relative response rate to rice seedlings dropped from positive to negative values at 2.5 and 3 h, the lack-of-response percentage increased notably, and the precise positioning rate on rice seedlings decreased significantly. These results demonstrate that SfurIR8a, SfurIR25a, and SfurIR76b are essential for olfactory perception and host-seeking behavior in S. furcifera. This study reveals the molecular basis of IRco-mediated olfactory processes in this pest and provides promising gene targets for developing novel olfactory-disruption strategies for rice pest management.

Root-knot nematodes (Meloidogyne spp.) are among the most damaging plant-parasitic nematodes, yet taxonomic uncertainties often complicate diagnostics and management. Here, we examined Meloidogyne silvestris populations from the Netherlands using an integrative approach combining morphology, isoenzyme profiles, and molecular markers. Morphological and morphometric traits, together with isozyme profiles, were highly consistent between the two Dutch populations and were complemented by near-identical 18S and 28S rDNA sequences, identical cox1 and cox2 barcodes, and a conserved mitochondrial genome architecture. In comparison with the original species description, these data support their identification as M. silvestris. We also present a nearly complete mitochondrial genome of M. silvestris, which expands genomic resources for root-knot nematodes. These findings highlight the value of integrative datasets for robust species delimitation and provide a framework for future studies on population structure, evolutionary dynamics, and diagnostic marker development within the genus.

Accurate identification of nematode communities is essential for understanding their ecological roles and functions in soil. However, the comparative analysis of morphology-based (MBI) and high-throughput sequencing (HTS) nematode community under contrasting irrigation regimes remains poorly understood. In this study, we investigated nematode community response in long-term mandarin and pomegranate orchard ecosystems managed under drip and surface irrigation using both identification approaches. Genera richness was consistently higher in HTS approach with 40 and 43 genera in mandarin and pomegranate orchards, respectively, compared with 29 genera each under MBI. This represents an improvement of 27.5-32.5% increase in genus detection. The Sorensen similarity index between approaches ranged from 0.37 to 0.53, indicating only low to moderate agreement. Identification approach showed a stronger effect on perceived nematode community composition than irrigation system (PERMANOVA, R2 = 0.61, p&#x2009;<&#x2009;0.01). HTS yielded higher Shannon diversity, evenness, structure index (SI), enrichment index (EI), and MI2-5 values, while MBI returned higher basal index and nematode channel ratio values, revealing that methodological choice could influence ecological interpretation of soil food web condition. Surface irrigation supported significantly greater bacterivorous nematode abundance, consistent with enhanced bacterial decomposition pathways under fluctuating soil moisture. In contrast, drip irrigation was associated with significantly higher MI, &#x2211;MI, and plant-parasitic index, collectively indicating a more structured, K-strategist-dominated community with greater plant-parasitic pressure. Soil food web assessment further revealed that MBI-based communities clustered predominantly in the structured quadrant, while HTS shifted communities toward the enrichment-structure transition zone, underscoring how detection capacity governs food web interpretation. These findings demonstrate that HTS and MBI provide complementary rather than interchangeable assessments of nematode biodiversity, and that irrigation management carries measurable, ecologically interpretable consequences for soil food web dynamics in orchard systems.

Tobacco thrips, Frankliniella fusca Hinds (Thysanoptera: Thripidae), are economically important early-season pests of seedling cotton and peanut in the southern United States, causing stand loss, delayed growth, and transmission of tomato spotted wilt virus (TSWV) in peanut. Historically, managing F. fusca has depended on insecticide seed treatments and in-furrow applications. However, control efforts are becoming more limited due to insecticide resistance and the partial suppression of virus transmission. ThryvOn cotton, which expresses the Bt protein Cry51Aa2.834_16, suppresses thrips feeding and reproduction without causing high mortality, raising questions about how this trait may influence thrips host use in mixed cropping systems. We evaluated oviposition preference and population abundance of F. fusca on peanut, ThryvOn cotton, and non-ThryvOn cotton using greenhouse no-choice, two-choice, and three-choice assays, as well as a field experiment in which all crops were planted side by side. Across all greenhouse assays, F. fusca consistently laid the greatest number of eggs on peanut, intermediate numbers on non-ThryvOn cotton, and the fewest on ThryvOn cotton. Field results closely reflected these patterns, with peanut supporting significantly higher egg, nymph, and adult densities throughout early vegetative growth, while ThryvOn cotton consistently harbored the lowest thrips populations. Our findings suggest that F. fusca exhibits a preference for peanut over cotton, particularly ThryvOn cotton, indicating that reduced host suitability of ThryvOn cotton may influence early-season thrips distribution in diversified cropping systems. Although thrips movement was not measured, this preference highlights the need to consider interactions when developing regional management strategies.

Potato cyst nematodes (Globodera pallida and G. rostochiensis) are quarantine pests that threaten global potato production. While European and North American populations often exhibit limited genetic diversity, native Andean populations possess a broader virulence spectrum. This study evaluated the virulence of 10 Peruvian Globodera populations compared to U.S. reference populations (G. pallida Pa2/3 from Idaho and G. rostochiensis Ro1 from New York) using a panel of potato genotypes comprising standard differentials, breeding clones, and commercial varieties. While the U.S. populations displayed expected virulence profiles, the Peruvian populations exhibited high diversity and complex virulence phenotypes. We identified a distinct "Pa1-like" G. pallida lineage (PER10) that was avirulent on H2 resistance in clone P55/7, a differential typically susceptible to the U.S. G. pallida population, and partially overcame the Pa2/3 resistance in the variety 'Maria Huanca'. Furthermore, specific Andean G. pallida populations (e.g., PER22) were virulent, overcoming partial resistance in the H3 breeding clone 12674ab1 with significantly higher reproduction than the U.S. G. pallida population. In contrast, the H1 gene in clone NY121, which confers resistance to G. rostochiensis Ro1, remained effective against the Andean G. rostochiensis population (PER26). These findings quantify a significant virulence gap between the U.S. and Peruvian Globodera populations, indicating that current U.S. resistance sources may be vulnerable to specific Andean Globodera lineages. The results underscore the necessity of strict quarantine measures and the pyramiding of diverse resistance genes to manage the virulence reservoir present in these native populations.

Trapped arthropods have been shown to benefit plants in several ways, but few studies have examined the potential costs of arthropod entanglement. Milkweeds (Asclepias spp.) have an unusual pollination system that requires relatively large packets of pollen (pollinia) to become attached to the appendages of insect pollinators and be pulled through a narrow opening in the flower. Honey bees (Apis mellifera) commonly become trapped and die with their legs still attached to milkweed flowers. In this study, we conducted a field experiment to examine how dead trapped honey bees affect floral visitation. We expected that the presence of a dead trapped bee would reduce floral visitation via two non-mutually exclusive pathways: (1) a direct deterrent effect on floral visitors and (2) an indirect deterrent effect mediated by an increased abundance of scavenging predators such as ants. The presence of a dead bee reduced floral visitation by 37% compared with controls, and this effect was stronger and more robust for honey bee visitors than non-Apis visitors. While ant densities were 51% higher on floral umbels with a dead bee and ants reduced floral visitation by 30%, our path analysis indicated that the direct deterrent pathway explained 91% of the total effect, consistent with an aversion to dead conspecifics among honey bees. Our results suggest that the lethal entanglement of honey bees is likely to incur an ecological cost for milkweed flowers, although the deterrence of honey bees could also shift the pollinator communities on milkweeds with unexpected consequences.

Understanding how fertilization shapes the composition and functioning of soil nematodes is critical for maximizing agricultural sustainability and plant productivity. However, we lack a unified understanding of how different fertilizer regimes influence the nematode-plant productivity relationship across the globe. This study aimed to investigate whether targeted fertilization, such as organic fertilization, alters nematode community structure and function, and how these changes relate to plant productivity. Here, we integrate a global meta-analysis of fertilization experiments and machine learning-based predictions to address this gap. We show that fertilizer type strongly regulates nematodes and plant performance globally. Organic fertilizers increase total nematode abundance, shift community composition toward bacterivore dominance and promote plant productivity, whereas mineral fertilizers weaken this positive effect and lead to a negative correlation between plant productivity and herbivores. Structural equation and global prediction models further indicate that these positive effects of bacterivores and organic fertilization on plant productivity are particularly strong in warmer climates, such as South Asia, Central Africa, and Northern South America, suggesting climatic modulation of fertilizer and soil nematode effects. These findings highlight that agricultural management traits fundamentally shape plant-nematode interactions, emphasizing the pivotal role of soil nematodes in linking fertilization practices to ecosystem productivity.

Pollen is essential for western honey bee (Apis mellifera L.) brood development, but the quality and quantity of pollen in the environment varies seasonally. Beekeepers often provide pollen substitute patties (PSPs) as a source of protein, lipids, and micronutrients when high-quality natural pollen is unavailable. Previous dye-tracing research has established that honey bees do not use PSPs the same way they use natural pollen; it is consumed by adult workers but is not stored or fed to larvae. Here, we determined the age at which adult workers interact with and consume PSPs to understand PSP utilization in honey bee colonies. We released cohorts of marked, newly emerged workers into hives containing dyed PSPs, undyed PSPs (negative control), dyed fondant (positive control), and dyed modeling clay (consumption control). We recorded the number of marked workers interacting with the treatments for 4 weeks following worker release. Additionally, we collected 20 marked workers daily from all colonies to assess the presence of dye in their guts. We constructed generalized linear mixed effect models and used Akaike's Information Criterion to perform model selection. Using our top models, we found PSP interaction and consumption gradually increased with worker age until peaking between 18 and 22&#x2009;days post cell emergence. These patterns suggest that older workers of pollen packer and foraging age, rather than nurse bees, are the primary consumers of PSPs. Our research suggests that PSP utilization may be driven by resource handling behaviors or carbohydrate consumption, rather than brood provisioning, when colonies are not pollen-limited.

Polyandry is a common reproductive behaviour in nature, and it was observed in several plant parasitic cyst nematodes. For the potato cyst nematode Globodera pallida, polyandry is assumed but has never been demonstrated and quantified. Since the potato resistance used to control this nematode, i.e., the resistance conferred by GpaV from Solanum vernei, acts by masculinizing populations, and because polyandrous mating is more frequent in male-skewed populations, the level of polyandry can be expected to decrease during the nematode adaptation process to potato resistance. Aims of this study were thus to determine whether polyandry occurs in G. pallida and to explore the polyandry evolution during the adaptation process to the potato resistance. Using G. pallida lineages obtained from experimental evolution on susceptible and resistant potato cultivars, we explored and quantified the genetic evidences of multiple paternity within cysts by genotyping juveniles using microsatellite loci. Results clearly highlighted multiple paternity in G. pallida and showed that 100% of females were polyandrous, with an average of seven fathering males. Contrary to our expectations, the frequency of polyandrous females and the female mating rate with different males, estimated from the minimum number of fathers, appeared to remain stable throughout the adaptation process to a masculinizing resistance. The level of polyandry highlighted here may represent an important parameter to consider in demo-genetic models designed to compare nematode population control strategies.

This study aims to identify and characterize the key virulence factors responsible for the activity of Bacillus velezensis A-27 against Heterodera glycines. Crude extracellular proteins derived from the A-27 fermentation broth resulted in 83.7% mortality in second-stage juveniles (J2s) within 48&#xa0;h, based on independent biological replicates, leading to severe damage to both the digestive and reproductive systems. Bioassay-guided fractionation isolated a protein fraction of approximately 39&#xa0;kDa that exhibited high nematicidal activity (55% mortality). LC-MS/MS analysis identified this protein as AprE, a serine peptidase belonging to the S8 family. Recombinant AprE expressed in Escherichia coli demonstrated dose-dependent nematicidal activity, achieving 99% mortality in J2s at a concentration of 100&#xa0;ng/&#x3bc;L within 24&#xa0;h (LC50&#xa0;=&#xa0;0.7719&#xa0;ng/&#x3bc;L), and reproduced the internal morphological damage observed in J2s treated with the crude protein extract. The critical role of AprE was further confirmed by a significant reduction in virulence observed in the A-27-&#x394;AprE mutant compared to the wild-type strain at 48&#xa0;h (83% vs. >99% mortality). Additionally, screening of 2967 metabolites revealed seven major compounds with direct-contact activity. Methyl acetoacetate proved to be the most potent (LC50&#xa0;=&#xa0;191&#xa0;mg/L) at 24&#xa0;h, followed by isobutyric acid, benzyl alcohol, glutaric acid, suberic acid, dibutyl phthalate, and elemonic acid. We conclude that the extracellular protease AprE serves as an important virulence factor in B. velezensis A-27, with secondary metabolites significantly enhancing its efficacy.

Environmental sex determination (ESD) enables organisms to adjust their sexual fate in response to external cues. Fluctuating sex ratios have long suggested the presence of ESD in populations of plant-parasitic nematodes. We show that in the potato cyst nematode Globodera pallida sex is regulated by nutritional cues. By manipulating sucrose availability to the host plant, we could steer the sex determination of G. pallida. Whereas high-sucrose medium promotes female development, low-sucrose medium promotes male development. Transcriptome analyses on the early stages of parasitism reveal that female development requires extensive transcriptional activation and post-transcriptional regulation. We identify Gp-lin-29, a transcription factor homologous to lin-29 in Caenorhabditis elegans, as a potential regulator of ESD. Small RNA sequencing uncovered the male-biased expression of Gp-let-7, a putative repressor of Gp-lin-29, and the female-biased expression of four miRNAs, including Gp-miR-100, located at the same genomic locus as Gp-let-7. Target prediction and enrichment analyses suggest that these female-biased miRNAs may actively suppress male developmental programs. Together, our findings support a model in which G. pallida juveniles follow a default male developmental trajectory unless redirected by favourable environmental cues to become female. This study provides mechanistic insight into ESD in cyst nematodes and positions G. pallida as a tractable system for exploring epigenetic regulation of developmental plasticity.