Exposure to sublethal stressor concentrations, which do not result in mortality, can trigger hormetic responses that enhance growth, reproduction or survival in both primary pest species and their secondary competitors, potentially contributing to the development of insecticide resistance and pest outbreaks. Hormesis, a dose-dependent biphasic response characterized by low-dose stimulation and high-dose inhibition, has garnered increasing attention in entomology and acarology owing to its significant implications for pest management and ecosystem service provision. By contrast, hormesis in natural enemies, such as pathogens, parasitoids and predators, can enhance their biological control performance under specific conditions. Although these responses may offer short-term benefits, they also introduce trade-offs and potential long-term risks. The underlying mechanisms of hormesis include hormonal modulation, stress-induced activation of cellular repair pathways and enhanced detoxification processes. Despite its significance, our understanding of hormesis in ecologically important insects and mites remains limited, with critical knowledge gaps regarding species-specific responses, the influence of environmental factors such as temperature and nutrition, and the long-term ecological consequences of repeated low-dose exposures. Furthermore, the interaction of multiple stressors, such as pesticide mixtures and abiotic factors such as climate change, remains poorly understood in the context of hormetic responses. Future research should focus on elucidating the molecular mechanisms of hormesis, its ecological implications, and the development of predictive models to assess its effects across various ecosystems. Integrating hormesis into pest management strategies could optimize pesticide use while minimizing adverse effects on beneficial organisms. Addressing these gaps is crucial for enhancing ecological resilience, safeguarding populations of beneficial organisms, and promoting sustainable agricultural practices in the face of environmental and anthropogenic challenges. © 2025 Society of Chemical Industry.
Rhipicephalus sanguineus (Latreille) is a species complex of ticks that are important vectors of many diseases to humans and other animals. In Arizona, the ranges of the 2 primary genetic variants-the temperate and the tropical lineages-overlap. The temperate and tropical lineages of R. sanguineus s.l. have divergent strains of the obligate Coxiella-like endosymbiont; however, it is unknown whether the microbiomes of the temperate and tropical lineages are otherwise different. There is growing evidence that non-pathogenic bacteria may be important components of vector-borne disease dynamics, even at low abundance. This research utilized a blocking primer to prevent sequencing of Coxiella to enable a closer examination of bacterial community structure of R. sanguineus s.l. ticks in Arizona. There were many commonalities among bacterial genera found within R. sanguineus s.l. ticks across the state, but no clear distinctions in bacterial community composition based on lineage, sex, female engorgement level, or collection location. Keywords: acarology, insect-symbiont interaction, microbiology, medical entomology.
Phytophagous mites of the family Tetranychidae cause agricultural losses, yet their viromes remain poorly characterized. We report the first viral survey of the peanut pest mite Tetranychus ogmophallos, identifying three novel positive-sense RNA viruses by high-throughput sequencing and genomic analyses. Tetranychus ogmophallos iflavirus 1 (ToIV-1) possesses a 10,003 nt genome encoding a typical iflavirus polyprotein and shares 58.8% amino acid identity with its closest relative, supporting recognition as a distinct species. Two additional viruses, Tetranychus ogmophallos nodavirus 1 (ToNV-1) and 2 (ToNV-2), were identified as bipartite alphanodaviruses with conserved RNA1:RNA2 abundance ratios of 2-3:1. Strand-specific RT-PCR confirmed genomic and antigenomic strands for ToIV-1 and ToNV-1, indicating active replication. Differential read analysis showed that ToIV-1 was 37-fold more abundant than ToNV-1, suggesting contrasting replication dynamics. These findings expand RNA virus diversity in spider mites and provide a basis for future studies on persistence and potential ecological relevance.
Spotted fever group (SFG) rickettsioses are tick-borne infectious diseases caused by more than 30 Rickettsia species. As ticks may harbor and transmit multiple pathogens during a single blood meal, sensitive and specific molecular detection methods are essential for early diagnosis. Conventional nested PCR is commonly used but is time-consuming and prone to cross-contamination due to multiple amplification steps. This study evaluated a dual-target one-step nested PCR assay developed as a rapid alternative to conventional nested PCR for SFG Rickettsia detection. Gene-specific primers targeting the Rickettsia outer membrane protein A (ompA) gene and the 17 kDa antigen gene were designed, with a Plasmodium falciparum thrombospondin-related anonymous protein (TRAP) gene included as an internal amplification control. Primer specificity was verified in silico, and assay performance was assessed using synthetic DNA templates. The dual-target one-step nested PCR achieved detection limits of 10 gene copies for the 17 kDa gene and 1000 gene copies for ompA, compared with 10 and 100,000 gene copies, respectively, using conventional nested PCR. Screening of 184 tick specimens identified one positive sample (0.54%) for the Rickettsia 17 kDa gene. Overall, the dual-target one-step nested PCR demonstrated comparable sensitivity to conventional nested PCR while reducing assay time and contamination risk, indicating its potential as a reliable tool for SFG Rickettsia detection.
While herbivore-induced plant volatiles are well-established cues that guide natural enemies to herbivores in ecosystems, microbe-induced plant volatiles have recently gained attention as promising tools for achieving similar outcomes. However, how nocturnal predators respond to volatile cues induced by herbivory and/or endophytic fungal remains poorly understood, particularly in systems where the predator and plant do not share a tightly co-evolved or highly specialized relationship. To explore this, we investigated whether Spodoptera frugiperda infestation and Metarhizium robertsii endophytic colonization in sugarcane plants could enhance the olfactory attraction of the nocturnal earwig predator Doru luteipes by modifying nocturnal volatile emissions and altering endogenous levels of jasmonic acid and salicylic acid. Unexpectedly, the changes in volatile emissions and phytohormone levels induced by herbivory and microbial colonization led to a reduced attraction of the predator compared with undamaged control plants and with the no-plant control. These findings highlight the complexity of D. luteipes' responses to induced indirect defenses in sugarcane, suggesting that such strategies may not consistently enhance the recruitment of natural enemies.
Chimeric hypoallergens of Der p 1 and Blo t 1 (QBD2/QBD4) reduce IgE reactivity and airway inflammation in mice. QBD4 promotes Th1/regulatory responses, suppressing mucus and eosinophilia more effectively than QBD2.
The biological control of phytophagous mites mediated by predatory mites promotes the maintenance of plant physiology by mitigating damage and preserving key traits related to photosynthesis and development. The immune system of plants, upon perceiving the presence of phytophagous mites, triggers signals mediated by reactive oxygen species (ROS). Under intense infestations, these redox signals can trigger oxidative stress, which compromises vital characteristics related to plant fitness. The use of pesticides as a management strategy is increasingly limited by resistance and collateral physiological impacts on plants. The release of predatory mites has emerged as an effective and sustainable biological approach. Predator-mediated foraging may suppress phytophagous mite infestations and mitigate the physiological stress of plants by limiting metabolic expenditures and physiological disturbances related to photosynthesis, growth, and reproduction. Thus, we review the benefits and risks of signals mediated by ROS in plants under attack by phytophagous mites. We conceptualize a stress state for plants under attack by these organisms and describe the benefits of foraging predatory mites reported in the literature from a meta-analytical perspective. Based on existing studies, we show that these natural enemies mitigate damage and the intensification of foliar chlorosis, limiting impacts on leaf area, the number of leaves, and the size of the plants. Furthermore, we speculate how the intensity of stress in the plant could act as a key point in the signals emitted to attract predatory mites. Finally, we emphasize the urgency of integrating this new perspective into future studies to improve the evaluation of the efficiency of natural enemies to benefit plant performance.
The diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae), is one of the major pests of Brassica crops worldwide, causing significant economic losses. Using resistant plant genotypes is a promising strategy for integrated pest management, as it reduces reliance on chemical insecticides and helps mitigate resistance development. This study evaluated the resistance mechanisms of different collard green (Brassica oleracea var. acephala) genotypes to P. xylostella. Both antixenosis and antibiosis were investigated through oviposition preference tests and biological performance assessment. According to the results, there was significant variation between the genotypes. Some genotypes exhibited strong oviposition deterrence, while others affected larval survival, development time, and pupal weight. These resistance effects were associated with physical and morphological leaf traits. Genotypes 32 GUA and HS showed reduced attractiveness for oviposition and inhibited larval development and survival. These traits were linked to higher leaf wax load, increased leaf hardness, and specific leaf color parameters. These findings indicate that resistance in collard greens to P. xylostella is mediated by a combination of physical and morphological factors, such as plant substrate color, leaf hardness, and surface wax content. Identifying and utilizing resistant genotypes can contribute to the integrated management of P. xylostella and reduce the need for chemical control measures. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
The public health risk of ticks and tick-borne diseases (TBDs) have been steadily increasing, partly due to ticks expanding their range into human proximity. However, there is lack of up-to-date information on tick species composition in West Malaysia, particularly within high-risk ecosystems for tick exposure. This study investigates the presence of tick species in 6 ecosystems of Pahang and Terengganu, where human TBD cases have been reported, through morphological and molecular identification approaches. A total of 153 small mammals were caught, dominantly from recreational forest (RF), belonging to 13 species. Of these, 68 were infested with ticks, to make an overall prevalence of 44.4%. Additionally, a total of 351 individual of feeding and questing ticks were collected. A mix life stages of these ticks were then identified as Amblyomma cordiferum Neumann 1899, Amblyomma geoemydae (Cantor, 1847), Amblyomma testudinarium Koch 1844, Dermacentor auratus Supino 1897, Dermacentor compactus Neumann 1901, Dermacentor steini (Schulze, 1933), Dermacentor tricuspis (Schulze, 1933), Dermacentor sp., Haemaphysalis hystricis Supino 1897, Haemaphysalis sp., and Ixodes granulatus Supino 1897. The most prevalent species was D. auratus (43%), followed by D. steini (16%) and I. granulatus (12.3%). Interestingly, this study is the first to report high infestation of various developmental stages of ticks on Tupaia glis (Diard, 1820) in Malaysia, highlighting its potential as a competent host for both and ticks and pathogens. These findings offer valuable evidence for public health authorities and sheds new light on tick species in TBD-related ecosystems, which can be applied for tick-management programs in Malaysia.
Maize striate mosaic virus (MSMV, species Mastrevirus striatis) is an emergent mastrevirus (Geminiviridae) in South America, transmitted by the corn leafhopper Dalbulus maidis. MSMV symptoms in maize (Zea mays) include mottling with mild chlorotic streaks, but the extent of its damage and host range remain unstudied. In greenhouse experiments, we assessed 17 plant species (including maize as a control) as hosts to MSMV by symptomatology and PCR detection in 9-30 test plants per species, which were inoculated by caging 20 viruliferous leafhoppers/plant during 48 h; 3-5 plants/species were exposed to aviruliferous leafhoppers (negative controls). MSMV was detected in four inoculated grass species, Urochloa brizantha, Andropogon gayanus, Saccharum spp. and Pennisetum glaucum, but only Saccharum spp. (cv. CTC-9005) showed symptoms (chlorotic stripes). In maize, the virus was detected in 51.8% of the inoculated plants, of which only 45.9% showed typical MSMV symptoms (mottling and/or chlorotic streaks). We also evaluated the MSMV pathogenicity in two maize hybrids after inoculation with viruliferous leafhoppers caged at a density of 20 individuals/plant for 72 h; the inoculated hybrid plants and respective controls (exposed or not to aviruliferous leafhoppers) were grown in pots in a greenhouse to assess symptoms and yield. A multivariate analysis showed that the MSMV impact on maize varied with infection type (symptomatic vs. asymptomatic). Both hybrids were highly affected when symptoms developed, whereas asymptomatic infection did not significantly alter plant development but still reduced grain yield in one hybrid. These findings are essential for understanding the virus impact, transmission ecology and management strategies.
The compatibility between insecticides and biological control agents is essential for the success of Integrated Pest Management (IPM) strategies. This study evaluated the lethal, sublethal, and transgenerational effects of 5 insecticides-malathion, bifenthrin, beta-cyfluthrin, diflubenzuron, and tebufenozide-on Trichogramma atopovirilia Oatman & Platner, 1983 (Hymenoptera: Trichogrammatidae), a parasitoid and potential biological control agent of Gymnandrosoma aurantianum Lima, 1927 (Lepidoptera: Tortricidae) in citrus orchards. The results showed that malathion, bifenthrin, and beta-cyfluthrin significantly reduced parasitism, emergence, and adult longevity. These insecticides were classified as harmful (Class 4), moderately harmful (Class 3), and slightly harmful (Class 2), respectively, according to the IOBC/WPRS guidelines. In contrast, diflubenzuron and tebufenozide were classified as harmless (Class 1), demonstrating minimal adverse effects on biological parameters and exhibiting low persistence under simulated field conditions. Transgenerational evaluations indicated that while emergence and sex ratio remained unaffected, longevity was reduced in certain treatments. These results highlight the importance of selecting insecticides that are compatible with natural enemies in IPM programmes, and suggest that insect growth regulators are a safe and effective alternative to conventional insecticides for conserving T. atopovirilia in citrus agroecosystems.
Soybean yield is often reduced by pest attacks. Among these, Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) stands out as one of the most important defoliating pests of soybean. Therefore, the development of new bioinsecticides targeting Lepidopteran pests is an urgent need. Protease inhibitors (PIs) have emerged as promising molecules in this context. In this study, we designed four peptides (TGPCK, TGPCR, AVIMK, and AVIMR) inspired by the reactive center loops of BPTI and SKTI to assess their potential as competitive inhibitors of trypsin-like proteases in A. gemmatalis. In silico and kinetic analyses revealed that peptide binding affinity was influenced by specific chemical interactions, with pi-sigma bonds correlating with higher affinity for AVIMK, while alkyl/pi-alkyl and C-H bonds were associated with lower affinity for AVIMR and TGPCK. Key residues (His57, Asp102, Ser195, Asp189, S195, and G197) played a crucial role in ligand binding. Enzyme inhibition assays confirmed that all peptides acted as competitive inhibitors of A. gemmatalis trypsin-glen proteases, with TGPCK displaying the highest efficacy. These findings highlight BPTI-derived peptides as potential candidates for future pest management strategies. Further studies should evaluate their effects when applied to plants, considering possible metabolic interactions and phytotoxicity.
This study investigates the potential of a protein-DNA aptamer conjugate to enhance aptamer binding to recombinant human intercellular adhesion molecule 1 (rhICAM-1). Aptamers are single-stranded nucleic acids that bind target molecules through hydrogen bonding and hydrophobic interactions. Conjugating aptamers with antibodies or proteins has been shown to improve their binding affinity. Using Systematic Evolution of Ligands by Exponential Enrichment (SELEX), eight rounds of selection were performed with ICAM-1-coupled Dynabeads Protein A, identifying a DI05 as having the strongest binding affinity to rhICAM-1. An antibody inhibition assay showed a significant reduction in rhICAM-1 binding to immobilized aptamers (DI05, DI20, DI31, and DI33). Additionally, the binding affinity of eGFP-conjugated DI05 to rhICAM-1 was higher than that of unconjugated DI05. Docking simulations revealed close contact between DI05 and ICAM-1, with interactions primarily mediated by hydrogen bonds within three hairpin structures at ≤2.8 Å. These findings highlight the potential of aptamer-small protein conjugates as a promising strategy to enhance aptamer binding characteristics.
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Social inequality among individuals is a common cause of conflict in the animal kingdom. In eusocial insects, such as ants, bees, wasps, and termites, for example, the large differences in reproductive potential between castes result in conflicts over caste fate during development. Here, we present the first comprehensive review on caste fate conflict, drawing on data from diverse taxa and recent theoretical advances. In many eusocial species, caste fate is determined by differential feeding, which results in caste fate being socially controlled, thereby aligning larval development with the collective needs of the colony. However, in some taxa, mechanisms of individual self-determination disrupt this balance, leading to overproduction of reproductive individuals at the expense of workers, with significant costs to colony fitness. Such conflicts are particularly pronounced in some stingless bees and lower termites, where larvae can bypass social control to determine their own caste fate. Indications of caste conflict can also be found in other groups, such as in some parasitic ants and in ant hybrid zones. Overall, the observed dynamics illustrate how conflicts in biological systems can be resolved in favour of either individual or collective interests, and how this affects the functioning of higher levels of organisation.
Blomia tropicalis is an important source of inhalant allergens in Southeast Asia and Latin America. Previous proteomics identified multiple Blo t 2 isoforms, yet their clinical relevance to Latin American populations and association with asthma phenotypes remain a priority in the field. To produce and purify the two recombinant isoforms rBlo t 2.2 and rBlo t 2.5 and physicochemically characterize them. Isoforms were expressed in E. coli Shuffle T7 and purified via cation-exchange chromatography. Structural features were verified by mass spectrometry and Fourier-transform infrared spectroscopy. Further, proteolytic stability and LPS-binding activity were determined. IgE-reactivity and allergenic activity were evaluated by Western blot, ELISA and mediator release assays. Sensitization patterns were analyzed in serum samples of Blomia tropicalis-allergic individuals with and without asthma from Brazil, Colombia, and Ecuador. Both isoforms were correctly folded with proper disulfide bonds and exhibited high stability against endolysosomal proteases. Recombinant Blo t 2.2 lacked specific LPS-binding activity and displayed low cross-reactivity with rDer p 2. Across the three countries, the average sensitization rate to rBlo t 2.2 was 50%. Specifically, sensitization was observed in 47% of Brazilian teenagers and 52% of adults, 53% of Colombian individuals, and 48% of Ecuadorian children and teenagers. Sera from the Ecuadorian study exhibited the highest IgE reactivity. The rBlo t 2.2 isoform displayed significantly higher IgE-binding than rBlo t 2.5 in Brazil. Sensitization to rBlo t 2.2 was significantly more frequent in severe asthma patients than in mild asthma and rhinitis patients. rBlo t 2.2 is a stable, mid-tier to major isoform and a candidate biomarker for severe asthma in Brazil. Its structural and immunological characteristics support its inclusion in molecular diagnostic panels. However further investigations with larger sample sizes and application of multivariate analyses are still warranted to confirm our findings.
The potato tuber moth (PTM), Phthorimaea operculella (Zeller), is a globally significant pest that attacks potatoes and many other Solanaceous crops. The ectoparasitic mite Pyemotes zhonghuajia Yu, Zhang & He is a promising biological control agent for PTM. This study investigated the effects of PTM larval body size (small and large) and P. zhonghuajia density (50, 150, and 250 mites) on host paralysis, as well as on the development and reproduction of P. zhonghuajia, aiming to optimize its mass production and application in PTM management. Our results showed that P. zhonghuajia females took significantly longer to paralyze and kill large PTM larvae at the lowest density (50 mites). Increasing mite density significantly decreased the parasitism rate per host, likely due to increased mutual interference among host-searching mites. However, the number of P. zhonghuajia females feeding on a single host increased significantly with mite density, resulting in smaller opisthosoma and fewer offsprings, suggesting food competition among females. Host size had a significant positive effect on opisthosoma size, offspring number per opisthosoma, and total offspring produced by P. zhonghuajia female, indicating that larger hosts provide more nutrients. The total number of offspring produced by P. zhonghuajia females from a host of a given size was similar across mite densities, suggesting that an optimal ratio of 50 P. zhonghuajia females per PTM larva is recommended for laboratory mass rearing and field augmentative release.
Glucosinolates (GSLs) from cruciferous vegetables (CVs), sulfur (S)- and nitrogen-containing compounds, are enzymatically hydrolyzed by myrosinase (EC 3.2.1.147) to yield bioactive derivatives such as isothiocyanates (ITCs) and indoles. These metabolites exhibit chemopreventive and anticancer properties. The article compiles evidence regarding the following: (i) the molecular mechanisms regulating the biosynthesis of key derivatives, including sulforaphane (SFN), phenethyl isothiocyanate (PEITC), and indole-3-carbinol (I3C); (ii) epidemiological and clinical findings; and (iii) strategies to link plant science with nutritional interventions for cancer prevention. An integrative literature review was conducted using Web of Science, Scopus, ScienceDirect, Google Scholar, and PubMed. English-language studies addressing mechanistic insights, nutritional factors, epidemiology, and clinical trials were included. The biosynthesis and metabolism of GSL in plants are regulated by S and several transcription factors that promote or repress GSL production. Additionally, food processing has been shown to influence retention time and the formation of ITCs. In humans, ITCs activate nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated detoxification, induce apoptosis, and modulate epigenetic pathways. Epidemiological data show inverse associations between CV intake and cancer risk, though variability exists. Clinical trials have confirmed the bioavailability and effects of glucoraphanin and SFN on cancer-related biomarkers. The described compounds are bioavailable in humans and modulate the clinically relevant pathways linked to carcinogenesis. Larger, standardized interventions are needed to determine effective intake levels, optimize bioavailability, and define their potential role in evidence-based nutritional strategies for cancer prevention.
A successful augmentative biological control program requires continuous and large-scale production of high-quality natural enemies, which depends on the development of appropriate storage techniques for these organisms and their hosts. In this study, we stored Euschistus heros (Fabricius, 1978) eggs at low temperatures, to determine the most viable storage condition and the duration for which these eggs can be stored without reducing acceptance by the parasitoid Telenomus podisi Ashmead, 1893, as well as the quality of its progeny (individuals to be released in the field). Egg storage was evaluated under three conditions: a conventional freezer (-15°C), an ultra-low temperature (ULT) freezer (-80°C), and liquid nitrogen (-196°C) for a period of 12 months. Parasitism of eggs stored under these three conditions was assessed at different intervals. The parasitoid parental (F0) generation was evaluated for parasitism, egg-to-adult development time, emergence, and sex ratio. In the progeny (F1), parasitism, emergence, and longevity in newly laid E. heros eggs were assessed. The ULT freezer and liquid-nitrogen storage conditions resulted in the highest parasitism rates of T. podisi in both the parental generation and its progeny. Storage in a conventional freezer was less suitable for parasitism and the viability of T. podisi. The results confirm that E. heros eggs can be stored in a ULT freezer or liquid nitrogen while maintaining their quality, thereby enabling production and storage during the off-season.
How dead bodies decay is useful forensically. Necrophagous astigmatan mites (Acari: Sarcoptiformes) commonly attacking cadavers change from protein-seeking Type 1 surface feeding omnivores to interstitial Type 2 fragmentary feeding obligate fungivore / microbiovores as human body decomposition progresses after death. An analytical occlusive method shows that at each forensic decay stage the chelae of the astigmatans are designed to bite foodstuff differently. Fixed chelal digits are more ‘toothy’ than moveable digits in such sarcoptiform mites. Variation in fixed digit design is all about the size and pattern of peaks (‘peakiness’) for biting, while astigmatan moveable digit variation is mainly about the size and pattern of valleys (’gullet-ness’) for the ‘scooping’ of decaying material. Foodstuff caught on the moveable digit is thus masticated against the fixed digit like an ‘excavation-bucket’ machine used for handling aggregates in building construction. Lardoglyphus zacheri has a distinct chela suitable to slice flesh and grip myofibrils. Acarus siro through Sancassania berlesei to Tyrophagus putrescentiae show a cline in digit design from a dry material ‘demolition crusher’ with rough surface digits, through a wet chunk and slice feeder, to a specialist multifunctional saprophage. Sancassania berlesei is unlikely to actively burrow into flesh. Trophic niche width increases from stage 2 (bloated putrefaction) as soft food specialist species invade. Niche width markedly widens at stage 5 (mummified dry desiccated bones and remains), as incorporation into a soil with diverse saprophagous mites is coming to completion.