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BACKGROUND: In agricultural pest management, especially in combatting the invasive red imported fire ant (RIFA, Solenopsis invicta), significant challenges emerge as a consequence of the constraints of solely depending on chemical insecticides or entomopathogenic nematodes (EPNs). The utilization of chemical insecticides carries environmental and ecological hazards, whereas EPNs, when applied independently, might not offer the immediate effectiveness necessary for adequate RIFA suppression. Acknowledging these hurdles, our study investigates a synergistic method that integrates EPNs with chemical insecticides, aiming to fulfill the urgent demand for more efficient and environmentally friendly pest control solutions. RESULTS: Our evaluation focused on the interaction between the highly pathogenic Steinernema riobrave 7–12 EPN strain and prevalent insecticides, specifically beta‐cypermethrin and a mixture of bifenthrin and clothianidin, applied at highly diluted recommended concentrations. The findings revealed a notable increase in RIFA mortality rates when EPNs and these insecticides were used together, outperforming the results achieved with each method individually. Remarkably, this enhanced efficacy was especially evident at lower concentrations of the bifenthrin–clothianidin mixture, indicating a valuable approach to minimizing reliance on chemical insecticides in agriculture. Furthermore, the high survival rates of EPNs alongside the tested insecticides indicate their compatibility and potential for sustained use in integrated pest management programs. CONCLUSION: Our research underscores the effectiveness of merging EPNs with chemical insecticides as a powerful and sustainable strategy for RIFA management. This combined approach not only meets the immediate challenges of pest control in agricultural settings, but also supports wider environmental objectives by reducing the dependency on chemical insecticides. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Simple Summary: The red imported fire ant, Solenopsis invicta Buren, is a highly invasive species. Some native ants may show aggression towards S. invicta and thus suppress S. invicta invasion. However, only a few such native ants have been identified, and the available data are largely limited to their behaviors. Here, we not only observed the aggression levels between native ants and S. invicta, but also investigated their abundance in various habitats, the seasonal dynamics of their abundance, and their spatial distribution in habitats with S. invicta. Two ant species, Monomorium chinense and Nylanderia bourbonica, were demonstrated to show aggression towards S. invicta and could kill a large proportion of S. invicta. However, another ant, Iridomyrmex anceps, did not show aggression. M. chinense and N. bourbonica are more abundant in green belts (e.g., lawns) and grasslands relative to woodland and farmland. Their abundance is quite low in the early months of the year but increases in later parts of the season. M. chinense and N. bourbonica are restricted to marginal habitats, but after control of S. invicta, they can rebound rapidly within a few weeks. M. chinense and N. bourbonica have the potential to suppress S. invicta invasion in some habitats. Native ants have long been considered for their potential to suppress the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), a highly invasive and destructive species. However, the knowledge in this field is limited to behavioral observations of a few related native ants. In this study, by setting up a series of ant combinations of three native ants, i.e., Monomorium chinense Santschi, the robust crazy ant Nylanderia bourbonica Forel, and Iridomyrmex anceps Roger, with S. invicta, we observed the aggression levels and mortality rates. Using baited vials, we also investigated the abundance of native ants in four types of habitats in Eastern China that are preferred by S. invicta (woodland, green belts on roadsides, grassland, and farmland), as well as their seasonal abundance when co-existing with S. invicta and their spatial distribution before and after control of S. invicta. We found that M. chinense and N. bourbonica show a degree of aggression towards S. invicta and can kill substantial proportions of S. invicta under laboratory conditions, but I. anceps does not. Both M. chinense and N. bourbonica can occur in each type of habitat investigated and are more abundant in green belts (particularly lawns with turf) and grasslands relative to other habitats. In grasslands with S. invicta, M. chinense maintained a low density before early July; however, its abundance increased thereafter and reached a peak in September. N. bourbonica also had a low density early in the season and increased steadily from April. Its abundance began to decrease substantially from November. In grasslands invaded by S. invicta, both M. chinense and N. bourbonica were restricted to sites close to the margins before S. invicta was controlled; however, they spread to a larger range within a few weeks after control of S. invicta. In conclusion, M. chinense and N. bourbonica have the potential to suppress S. invicta invasion in habitats that are abundant with these two native ants. [ABSTRACT FROM AUTHOR]

Background: Anaphylaxis represents the most severe end of the spectrum of allergic reactions. Frequent elicitors of anaphylaxis are insects, foods, and drugs. This paper summarizes recent development with regard to emerging and novel elicitors of anaphylaxis. Summary: Food allergens on the rise include pulses (like pea, chickpea), seeds (hemp, chia), nuts (cashew), pseudograins (buckwheat, quinoa), fruits, and microalgae. Novel foods are foods that were not consumed to any significant extent in the European Union before May 1997, which includes four edible insects (mealworm, migratory locust, house cricket, and buffalo worm). Recent investigations have pointed out the risk of anaphylaxis associated with the consumption of yellow mealworm for people allergic to shellfish and house dust mites. In Europe, fire ants (mostly Solenopsis invicta) and Vespa velutina nigrithorax represent invasive species, which account for increasing numbers of anaphylactic reactions. Also, several new drugs, especially biologicals, have been associated with anaphylaxis. Key Messages: Elicitors of anaphylaxis are changing as a result of (i) increase in demand for plant-based food, (ii) introduction of novel foods, (iii) spreading of allergens by climate changes and globalization, or (iv) due to exposure to newly developed drugs. [ABSTRACT FROM AUTHOR]

The rafting behaviour of the red imported fire ant, Solenopsis invicta, in response to flooding events is well documented, although studies generally have focussed on the mechanisms of raft assembly and the behaviour of the raft's occupants. Flooding as a means of dispersal of S. invicta is frequently mentioned in the literature, although there are few data on the distances travelled or how effective it is compared to natural flight. In Australia, S. invicta is a priority invasive species with a national eradication program operating for 23 years, focussed on the population in southeast Queensland, which currently encompasses more than 700 000 ha. Flooding presents a risk to the success of the program through extending the infestation area or recolonising successfully treated areas. We used the program's extensive spatiotemporal dataset of known fire ant colony locations to assess the effects of two significant flood events on the dispersal or displacement of S. invicta in Queensland. Results indicated that flooding did not spread S. invicta beyond the known boundaries of infestation but contributed to localised spread, particularly for sites with known polygyne infestations. This situation could change if the ant spreads to new river catchments. A novel method developed to assess the risk of S. invicta dispersal through flooding is presented, alongside program actions that can be applied to mitigate this risk. [ABSTRACT FROM AUTHOR]

Biological invasion is one of the major challenges to changing ecosystems worldwide. Red fire ants are a prime example of invasive soil animals. However, the impacts of their invasion on the native soil animal communities are still poorly understood. Here, we investigated how the biomass and diversity of soil microarthropods (incl., Collembola and Acari) vary between areas affected by red fire ants at different degrees (i.e., OA, occurrence area, 0–20 m from the nest; PCA, prevention and control area, 20–50 m; POA, potential occurrence area, 50–100 m). We also tested whether the potential effects of ant invasion on other animals are associated with changes in soil properties in the invaded areas. Our results showed a decline of 64% in species richness, 74% in density, and 72% in biomass of microarthropods in OA in comparison with POA. This reduction was mainly driven by the decrease of Acari, while no reduction in Collembola biomass was observed. Despite soil properties being significantly different between ant‐impacted areas, structural equation models indicated that the direct association of invasion with microarthropod communities is stronger than the indirect association mediated by soil properties. Therefore, we consider that direct biological interaction is more likely the major mechanism behind the observed changes in microarthropod communities. The effects of red fire ants were different among taxonomic and functional groups, with litter‐dwelling Collembola, Oribatida, and Mesostigmata (Acari) affected more negatively than soil‐dwelling and surface‐dwelling Collembola. Further, red fire ants affected the turnover component of beta‐diversity (i.e., replacement of species) for both Collembola and Acari. However, the impact on the nestedness component, which is related to species local extinction and population decline, was only detected for Acari. Our study shows that red fire ant invasion is associated with the depletion of soil microarthropod community, and especially highlights that Acari are more vulnerable to this invasion compared to Collembola. The divergent response between different taxonomic and functional groups of microarthropods and the consequent shift in microarthropod communities may have important significance to soil ecological functioning in the impacted areas. [ABSTRACT FROM AUTHOR]

This article provides an overview of medically important non-marine envenomations in the United States, focusing on spiders, pit vipers, coral snakes, scorpions, Gila monsters, hymenoptera, caterpillars, and blister beetles. It discusses the clinical manifestations, treatment, and disposition for each species, with a specific emphasis on brown recluse and black widow spider bites. The article highlights the importance of prompt recognition and treatment of envenomations and provides resources such as poison control centers and medical toxicologists for assistance. It also provides information on the clinical manifestations and treatment of snake bites, emphasizing the need for addressing airway, breathing, and circulation, and administering antivenom if necessary. The document further discusses the treatment and management of envenomations caused by Gila monsters, Hymenoptera, caterpillars, and blister beetles, stressing the importance of monitoring patients and seeking guidance from medical professionals when needed. [Extracted from the article]

A wide range of approaches has been used to manage the spread of invasive species, yet invaders continue to be a challenge to control. In some cases, management actions have no effect or may even inadvertently benefit the targeted invader. Here, we use the mid‐20th century management of the Red Imported Fire Ant, Solenopsis invicta, in the US as a motivating case study to explore the conditions under which such wasted management effort may occur. Introduced in approximately 1940, the fire ant spread widely through the southeast US and became a problematic pest. Historically, fire ants were managed with broad‐spectrum pesticides; unfortunately, these efforts were largely unsuccessful. One hypothesis suggests that, by also killing native ants, mass pesticide application reduced competitive burdens thereby enabling fire ants to invade more quickly than they would in the absence of management. We use a mechanistic competition model to demonstrate the landscape‐level effects of such management. We explicitly model the extent and location of pesticide applications, showing that the same pesticide application can have a positive, neutral, or negative effect on the progress of an invasion, depending on where it is applied on the landscape with respect to the invasion front. When designing management, the target species is often considered alone; however, this work suggests that leveraging existing biotic interactions, specifically competition with native species, can increase the efficacy of management. Our model not only highlights the potential unintended consequences of ignoring biotic interactions, but also provides a framework for developing spatially explicit management strategies that take advantage of these biotic interactions to work smarter, not harder. [ABSTRACT FROM AUTHOR]

BACKGROUND: Given the chemical diversity within stink bugs scent glands, they can be convenient models for bioprospecting novel pest control products. Preliminary behaviour observations indicated that adult Mictis fuscipes stink bugs secrete liquid droplets when defending against Solenopsis invicta fire ants, killing them within minutes. Hence, this study aimed to analyse the chemical composition of the metathoracic scent gland secretions of M. fuscipes adults, as well as assess their biological activities against fire ants. RESULTS: Bioassaying fire ants against secretions of several local stink bugs confirmed that the defensive secretions of two Mictis species are significantly more lethal, where M. fuscipes was the most lethal. Volatiles chromatography analysis indicated the secretions of female and male M. fuscipes stink bugs contains 20 and 26 components, respectively, chiefly hexanoic acid and hexyl hexanoate. Five compounds were consistently present in the secretion of female adults: hexyl hexanoate, hexanoic acid, hexyl acetate, hexyl butyrate, and eugenol. These yielded a strong electrophysiological antennal (EAD) response from S. invicta workers, female alates and males, where hexyl acetate showed the strongest response. The combination of these five compounds proved strongly repellent to S. invicta. When tested singly, hexanoic acid, hexyl butyrate, hexyl hexanoate, and eugenol were repellent to S. invicta, but hexyl acetate seemed slightly attractive. Additionally, the same mixture of five components exhibited strong contact and fumigant toxicity towards S. invicta workers, eugenol being the strongest. CONCLUSION: Defensive chemicals of M. fuscipes exhibit robust biological activity against S. invicta and could inspire the development of biopesticides. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In an ant colony, a large number of nestmates with a similar gene pool coexist, making them more vulnerable to pathogenic attacks. These pathogens influence the behavior and physiology of the fire ant Solenopsis invicta Buren. Here, we evaluated the impact of entomopathogenic fungi (EPF) Metarhizium anisopliae on the behavior (locomotion and foraging) and physiology (biological molecules, anti-fungal activity, and survival) of S. invicta. Distance traveled and velocity significantly decreased, while turn angle and angular velocity significantly increased in ants exposed to a higher concentration of M. anisopliae compared to ants exposed to control after 36 h, which showed disturbed locomotion. Fungus infection significantly affected the foraging behavior of ants. Fungus-exposed ants spent significantly less time in the food zone (area with food) than in the inner zone (area without food). The activities of 4 enzymes, peroxidase, glutathione-S-transferase, hydrogen peroxide (H2O2), and carboxylesterase were significantly decreased. In contrast, catalase and anti-fungal activities were increased after fungal exposure compared to the control. The activity of acetylcholinesterase, which hydrolyses the important neurotransmitter acetylcholine, also decreased after fungal application compared to the control. Survival of ants was also significantly reduced after fungus infection compared to the control. Our findings help to understand the influence of M. anisopliae on the behavior and physiology of S. invicta , which will help in the management of S. invicta using the EPF M. anisopliae. [ABSTRACT FROM AUTHOR]

The response of soil microorganisms and plants in soil ecosystems to biochar is well recognised. However, biochars' impact on large soil animal, such as ants, is inadequately understood, with only limited studies focusing on the abundance and mortality rates of some specific ant species. In this study, soil physicochemical properties, and ant community diversity and functional characteristics were compared between experimental plots with and without biochar application. No significant differences in soil (soil physicochemical properties) or ants (ant community richness, species abundance, and morphological characteristics) were observed between the two plots before biochar application. However, the biochar-treated plot soil surface temperatures, pH, and soil water content were significantly higher after 48 weeks. Biochar application promoted Cardiocondyla nuda (by 426%) and Formica japonica abundance (by 93%), but decreased Solenopsis invicta invasive ant species richness (by 54%), consistent with the fact that changes in soil properties were more beneficial to the former two species. In addition, in biochar-treated plots, F. japonica and S. invicta generally showed larger body size (18% and 6.7%), larger eyes (2.7% and 4.0%), and longer femurs (6.3% and 7.9%), which enabled them to respond better to potential barriers, such as plants. Our results highlighted that, besides species abundance and community structure, certain ant functional morphological indicators were also informative in evaluating biochar ecological implications. Highlights: Biochar application enhanced soil temperature, pH, and water content. Ants showed larger body size, larger eyes, and longer femurs with biochar application. Biochar promoted ant richness by creating ant-preferred habitats. [ABSTRACT FROM AUTHOR]

Increasing plant diversity in agroecosystems is well‐known to strengthen natural pest suppression, yet reliably predicting which non‐crop management practices best support natural enemies remains a challenge. Farmers often supplement diversity with managed flower patches or by allowing weedy non‐crop plant growth, both of which may support diverse, abundant and balanced communities of insect predators that provide biocontrol.At the same time, evenness among predators and effectiveness of biocontrol may be compromised by dominant arthropod invaders that co‐benefit from non‐crop diversity.We examined whether floral resources or adjacent weeds had stronger effects on the evenness and abundance of natural enemies by surveying plants and insects on zucchini crops at 37 organic farms.Neither flower richness nor weed richness affected insect predator evenness. Instead, the abundance of an invasive predator, the red imported fire ant (Solenopsis invicta Buren), increased with floral resource diversity, which negatively predicted the evenness and abundance of non‐invasive predators.These results suggest that floral diversity might be a less reliable predictor of natural enemy diversity when invasive predators interfere. Habitat management recommendations for bolstering biocontrol services should consider and potentially mitigate unintended consequences of floral resource provisions on farms where invasive predators dominate. [ABSTRACT FROM AUTHOR]

The N6‐methyladenosine (m6A) modification of RNA has been reported to remodel gene expression in response to environmental conditions; however, the biological role of m6A in social insects remains largely unknown. In this study, we explored the role of m6A in the division of labour by worker ants (Solenopsis invicta). We first determined the presence of m6A in RNAs from the brains of worker ants and found that m6A methylation dynamics differed between foragers and nurses. Depletion of m6A methyltransferase or chemical suppression of m6A methylation in foragers resulted in a shift to 'nurse‐like' behaviours. Specifically, mRNAs of dopamine receptor 1 (Dop1) and dopamine transporter (DAT) were modified by m6A, and their expression increased dopamine levels to promote the behavioural transition from foragers to nurses. The abundance of Dop1 and DAT mRNAs and their stability were reduced by the inhibition of m6A modification caused by the silencing of Mettl3, suggesting that m6A modification in worker ants modulates dopamine synthesis, which regulates labour division. Collectively, our results provide the first example of the epitranscriptomic regulation of labour division in social insects and implicate m6A regulatory mechanism as a potential novel target for controlling red imported fire ants. [ABSTRACT FROM AUTHOR]

The insect gustatory system participates in identifying potential food sources and avoiding toxic compounds. During this process, gustatory receptors (GRs) recognize feeding stimulant and deterrent compounds. However, the GRs involved in recognizing stimulant and deterrent compounds in the red imported fire ant, Solenopsis invicta, remain unknown. Therefore, we conducted a study on the genes SinvGR1, SinvGR32b, and SinvGR28a to investigate the roles of GRs in detecting feeding stimulant and deterrent compounds. In this current study, we found that sucrose and fructose are feeding stimulants and the bitter compound quinine is a feeding deterrent. The fire ant workers showed significant behavior changes to avoid the bitter taste in feeding stimulant compounds. Reverse transcription quantitative real‐time polymerase chain reaction results from developmental stages showed that the SinvGR1, SinvGR32b, and SinvGR28a genes were highly expressed in fire ant workers. Tissue‐specific expression profiles indicated that SinvGR1, SinvGR32b, and SinvGR28a were specifically expressed in the antennae and foreleg tarsi of workers, whereas SinvGR32b gene transcripts were also highly accumulated in the male antennae. Furthermore, the silencing of SinvGR1 or SinvGR32b alone and the co‐silencing of both genes disrupted worker stimulation and feeding on sucrose and fructose. The results also showed that SinvGR28a is required for avoiding quinine, as workers with knockdown of the SinvGR28a gene failed to avoid and fed on quinine. This study first identified stimulant and deterrent compounds of fire ant workers and then the GRs involved in the taste recognition of these compounds. This study could provide potential target gustatory genes for the control of the fire ant. [ABSTRACT FROM AUTHOR]

Juvenile hormone (JH) acts in the regulation of caste differentiation between queens and workers (i.e., with or without reproductive capacity) during vitellin synthesis and oogenesis in social insects. However, the regulatory mechanisms have not yet been elucidated. Here, we identified a highly expressed microRNA (miRNA), miR‐1175‐3p, in the red imported fire ant, Solenopsis invicta. We found that miR‐1175‐3p is prominently present in the fat bodies and ovaries of workers. Furthermore, miR‐1175‐3p interacts with its target gene, broad‐complex core (Br‐C), in the fat bodies. By utilizing miR‐1175‐3p agomir, we successfully suppressed the expression of the Br‐C protein in queens, resulting in reduced vitellogenin expression, fewer eggs, and poorly developed ovaries. Conversely, decreasing miR‐1175‐3p levels led to the increased expression of Br‐C and vitellogenin in workers, triggering the "re‐development" of the ovaries. Moreover, when queens were fed with JH, the expression of miR‐1175‐3p decreased, whereas the expression of vitellogenin‐2 and vitellogenin‐3 increased. Notably, the suppression of fertility in queens caused by treatment with agomir miR‐1175‐3p was completely rescued by the increased vitellogenin expression induced by being fed with JH. These results suggest the critical role of miR‐1175‐3p in JH‐regulated reproduction, shedding light on the molecular mechanism underlying miRNA‐mediated fecundity in social insects and providing a novel strategy for managing S. invicta. [ABSTRACT FROM AUTHOR]

Simple Summary: Invasive insect pests adversely impact human welfare and global ecosystems. However, no studies have compared the future invasion risk of invasive insect pests using a unified scheme. We compared the future range dynamics of 15 of the world's worst invasive insect pests. Although future range dynamics varied substantially among the 15 worst invasive insect pests, most exhibited large range expansions. The Asian tiger mosquito, cypress aphid, and Khapra beetle occurred four times in the top five largest potential ranges under most of the four climate scenarios examined. The Asian longhorned beetle, Asian tiger mosquito, and Formosan subterranean termite were predicted to have the largest range expansions. The Asian longhorned beetle, New Guinea flatworm, Formosan subterranean termite, and red imported fire ant exhibited the largest range centroid shifts. Strategies for their detection and management should be species-specific. This study furthers the understanding of how habitat changes may affect the ecology and shifts in the invasive potential of these insects. Invasive insect pests adversely impact human welfare and global ecosystems. However, no studies have used a unified scheme to compare the range dynamics of the world's worst invasive insect pests. We investigated the future range shifts of 15 of the world's worst invasive insect pests. Although future range dynamics varied substantially among the 15 worst invasive insect pests, most exhibited large range expansions. Increases in the total habitat suitability occurred in more than ca. 85% of global terrestrial regions. The relative impacts of anthropogenic disturbance and climate variables on the range dynamics depended on the species and spatial scale. Aedes albopictus, Cinara cupressi, and Trogoderma granarium occurred four times in the top five largest potential ranges under four future climate scenarios. Anoplophora glabripennis, Aedes albopictus, and Co. formosanus were predicted to have the largest range expansions. An. glabripennis, Pl. manokwari, Co. formosanus, and So. invicta showed the largest range centroid shifts. More effective strategies will be required to prevent their range expansions. Although the strategies should be species-specific, mitigating anthropogenic disturbances and climate change will be essential to preventing future invasions. This study provides critical and novel insights for developing global strategies to combat the invasions of invasive insect pests in the future. [ABSTRACT FROM AUTHOR]

Ant diversity in tropical montane rainforests is globally understudied. This is true for Cusuco National Park (CNP), a cloud forest ecosystem in northwestern Honduras that supports geographically isolated and threatened habitats. The current study presents the first comprehensive ant species checklist for CNP , which is also the first ant checklist for Honduras in over a century. Species records from several projects are also combined and presented. Sampling occurred along an elevational range (mainly between 1170 and 2030 m a.s.l.), with methodologies and intensities varying among projects and dates. Overall, 162 ant species belonging to nine subfamilies and 60 genera are reported from the CNP. Five species are recorded for the first time in Honduras (Pheidole natalie Longino, 2019; Strumigenys cf. calamita; Solenopsis invicta Buren, 1972; Solenopsis texana/carolinensis; Pseudomyrmex pallens Mayr, 1870). For the first time, male individuals are reported in Pheidole balatro Longino, 2019. For each species, we provide information on observed habitat preference, elevational range, and sampling technique. Species accumulation curves are provided for each sample technique, representing sampling intensity and community sample coverage. We also provide a key to the ant genera of Honduras to aid future taxonomic efforts in the country. Our research demonstrates that CNP harbours a surprisingly rich diversity of ant species, despite its small area, similar to many other taxa in the park. The information provided here represents baseline information for future work on ants in CNP and other Honduran cloud forests and will help guide research in these otherwise poorly explored yet highly threatened ecosystems. [ABSTRACT FROM AUTHOR]

This article is a personal reflection by Mamiko Ozaki on her experience working with Bill Pak at Purdue University in the 1980s. Ozaki discusses how Pak hired her husband as a post-doctoral researcher and offered her a position in his laboratory, despite her not having a Ph.D. at the time. She describes her work isolating the ninaA gene in blind Drosophila mutants and the challenges she faced in her research. Ozaki also mentions the impact of her time at Purdue on her subsequent career in chemosensory research. She expresses gratitude to Bill Pak for his mentorship and the opportunities he provided. The article also discusses the author's research on the olfactory system in ants and their ability to recognize pheromones. The author describes their work in identifying the sensory response to non-nestmate pheromones and the neuronal network involved in this process. The findings have practical applications in pest control. The author also mentions their new project on studying the odor of human babies and its potential influence on child-rearing and bonding. The article concludes with the author's reflections on their career and the opening of their own company. [Extracted from the article]

In order to clarify the occurrence of Solenopsis invicta in Quanzhou area and screen out the effective prevention and control agents suitable for the local Solenopsis invicta, the field control effects of 1% thiamethoxam amine granules, 1.8% abamectin cream, 0.05% indoxacarb bait and 5% rotenone soluble concentrate on the red fire ants were determined by investigating the habitat environment, living habits and transmission routes of the local Solenopsis invicta, in order to screen the best prevention and control agents. The results showed that the Solenopsis invicta in Quanzhou area were mainly distributed in the grassland (lawn), nursery, park, farmland, orchard and green belt, of which the suitable active temperature was 19-32°C. And they had mixed feeding distance habits, strong adaptability and various modes of spreading and diffusion. The field pharmacodynamic test showed that 1% thiamethoxam amine granules and 0.05% indoxacarb bait had good quick-acting property and durable effect on the active ant nests and active ergates. Although the 5% rotenone soluble concentrate had slightly slow quick-acting property, it had good persistence, while the quick-acting property and durable effect of 1.8% abamectin cream were both poor. Therefore, 1% thiamethoxam amine granules, 0.05% indoxacarb bait and 5% rotenone soluble concentrate were suitable for being promoted and applicated in the field. The results of this study could provide technical support and scientific basis for formulating the targeted prevention and control measures. [ABSTRACT FROM AUTHOR]

Simple Summary: The red imported fire ant is an invasive pest worldwide and a social insect that presents a significant risk to agricultural productivity, ecosystems, and human health. This work presents the selection of three nanomaterials out of a total of 16 species. We assessed the toxicity and behavioral alteration effects of these three materials individually, as well as in combination with indoxacarb, on red imported fire ants. The results showed that diatomite and multi-walled carbon nanotubes could enhance the activity of indoxacarb against red imported fire ants and inhibit their colony behavior. Diatomite and multi-walled carbon nanotubes can be added as pesticide additives to improve the control effects on red imported fire ants, reduce the use of indoxacarb, and delay the development of resistance. The red imported fire ant (Solenopsis invicta Buren) is one of the 100 worst invasive alien species in the world. At present, the control of red imported fire ants is still mainly based on chemical control, and the most commonly used is indoxacarb bait. In this study, the contact and feeding toxicity of 16 kinds of nanomaterials to workers, larvae, and reproductive ants were evaluated after 24 h, 48 h, and 72 h. The results showed that the mortality of diatomite, Silica (raspberry-shaped), and multi-walled carbon nanotubes among workers reached 98.67%, 97.33%, and 68%, respectively, after contact treatment of 72 h. The mortality of both larval and reproductive ants was less than 20% after 72 h of treatment. All mortality rates in the fed treatment group were below 20% after 72 h. Subsequently, we evaluated the digging, corpse-removal, and foraging behaviors of workers after feeding with diatomite, Silica (raspberry-shaped), and multi-walled carbon nanotubes for 24 h, which yielded inhibitory effects on the behavior of red imported fire ants. The most effective was diatomite, which dramatically decreased the number of workers that dug, extended the time needed for worker ant corpse removal and foraging activities, decreased the number of workers that foraged, and decreased the weight of the food carried by the workers. In addition, we also evaluated the contact and feeding toxicity of these three nanomaterials in combination with indoxacarb on red imported fire ants. According to contact toxicity, after 12 h of contact treatment, the death rate among the red imported fire ants exposed to the three materials combined with indoxacarb reached more than 97%. After 72 h of exposure treatment, the mortality rate of larvae was more than 73% when the nanomaterial content was above 1% and 83% when the diatomite content was 0.5%, which was significantly higher than the 50% recorded in the indoxacarb control group. After 72 h of feeding treatment, the mortality of diatomite, Silica (raspberry-shaped), and multi-walled carbon nanotubes combined with indoxacarb reached 92%, 87%, and 98%, respectively. The death rates of the three kinds of composite ants reached 97%, 67%, and 87%, respectively. The three kinds of composite food had significant inhibitory effects on the behavior of workers, and the trend was largely consistent with the effect of nanomaterials alone. This study provides technical support for the application of nanomaterials in red imported fire ant control. [ABSTRACT FROM AUTHOR]

Ants can particularly make for harmful pests, infesting human homes and reducing crop yields. The damage caused by ants and the efforts to mitigate the damage are hugely costly. Broad-spectrum insecticides are used most commonly; however, due to their negative side effects, there is increasing interest in nontoxic alternatives. One promising commercially available alternative is 2-hydroxybenzaldehyde, which is naturally produced by various arthropods as a means of chemical defense and effectively repels ants. Here we conduct a structure–activity relationship investigation, testing how different chemical modifications alter the repellence of 2-hydroxybenzaldehyde. We find that 2-methoxybenzaldehyde is considerably more effective than 2-hydroxybenzaldehyde at repelling the common black garden ant, Lasius niger. We next compare the most effective repellent chemicals against 4 particularly harmful ant species to confirm that the results obtained with L. niger are general to ants and that our results are relevant to mitigate the costs of ant damage. [ABSTRACT FROM AUTHOR]

Several protected troglobitic invertebrate species are known to occur in caves on Joint Base San Antonio—Camp Bullis, Bexar County, Texas, United States. The United States Fish and Wildlife Service (USFWS) identified red-imported fire ant Solenopsis invicta (hereafter RIFA) (Buren 1972) as the primary threat to cave species' nutrient sources, cave crickets, Ceuthophilus secretus (Scudder 1894). Per the service's recommendations, Joint Base San Antonio—Camp Bullis currently implements boiling water mound injections with digging for RIFA control. However, treatment effectiveness is highly variable and largely dependent on the time of day, weather, and personnel diligence. Toxicants have been used for RIFA treatment throughout the world, but concerns exist that traditional applications of toxicant bait around caves might be accessible and inadvertently affect nontarget arthropods, including cricket populations. To mitigate this accessibility, physically limiting access to the toxicant from crickets may be an option. Our objectives were to (i) compare and evaluate the effectiveness of Amdro (Hydramethylnon) and Advion (Indoxacarb) granular baits housed in Ants-No-More Bait Stations (Kness MFG. Inc. Albia, IA) and (ii) evaluate the distance of effectiveness of each bait within a bait station. Ultimately, we observed a 98% reduction in RIFA mound abundance from both baits. Additionally, RIFA mounds within 10 m of the containerized toxicant were reduced by 70%. Our pilot study suggested that Ants-No-More Bait Stations are an effective way to reduce RIFA mounds by 70% if placed 10 m from each other. In practice, this could include bait stations completely covering a particular distance to a cave entrance or fewer bait stations in a ring barrier at a single radial distance to a cave entrance. Containerized toxicants may be a cost-effective and safe RIFA control option around protected cave environments, but further studies are needed to determine potential effects on nontarget arthropods, optimal bait station configuration, and potential effects of biomagnification. [ABSTRACT FROM AUTHOR]

Florida has become a worldwide hotspot for introduced and invasive ants (Hymenoptera: Formicidae). Furthermore, studies have shown that non-native ants support other invasive insects in Florida, such as the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), which is the vector of Candidatus Liberibacter asiaticus, the causal pathogen of citrus greening, the worst citrus disease in the world. The Asian citrus psyllid establishes beneficial interactions with invasive, introduced, and native ants. In this study, we described the ant diversity in a citrus grove in south Florida as a first step to assess ant-Asian citrus psyllid interactions for future studies. During the summer of 2018, 25 pitfall traps were set in a citrus grove. The red imported fire ant, Solenopsis invicta (Buren), was present in all the traps (100 %), and 19 traps (76 %) had Dorymyrmex bureni (Trager), the pyramid ant, which is native to the southeast United States. Two introduced ants, Cardiocondyla emeryi (Forel) and Brachymyrmex obscurior (Forel), were found in 15 (60 %) and 11 (44 %) traps, respectively. The South American big-headed ant, Pheidole obscurithorax (Naves), was found in 14 traps (56 %). This introduced ant has been found to co-exist with S. invicta, and to our knowledge, this is the first report of the species in this eastern part of peninsular Florida. Finally, Cardiocondyla venustula (Wheeler), an introduced ant from Africa, was found in one of the traps. Although, this ant is found in south Florida, it seems uncommon, and this is its first report in this county. Our study highlights the continued spread of introduced and invasive ants in Florida. [ABSTRACT FROM AUTHOR]

Simple Summary: Solenopsis invicta (Hymenoptera: Formicidae), also known as the red imported fire ant, is a social insect and a worldwide invasive pest. Biochar is a widely used soil amendment. In this work, we investigated the effects of varying soil biochar levels on irritability and contact toxicity as well as the behavioral and physiological changes in red fire ant behavior. High doses of biochar were toxic and repulsive to red fire ants, impairing their ability to walk, grasp, attack, and gather while also causing an increase in the activity of enzymes associated with oxidative stress. This study supports the prudent utilization of biochar as well as the prevention and management of red fire ants. Solenopsis invicta, often known as the red imported fire ants (RIFAs), is a well-known global invasive ant species that can be found in agricultural, urban, and natural environments worldwide. Simultaneously, it also inhabits the soil. Biochar is generated by the pyrolysis of organic matter under high-temperature anoxic environments and widely used in agricultural ecosystems and soil amendment. However, to date, it remains unknown as to whether soil application of biochar has a negative effect on RIFAs. In our study, we investigated the toxicity and irritability effects of different amounts of biochar (0%, 1%, 2%, 5%, 10%, and 20%) introduced into the soil on red fire ants; upon comparison with the control soil (0% biochar), the application of 1%, 2%, and 5% biochar did not result in significantly different results. But the utilization of biochar at a concentration over 10% effectively repelled the RIFAs, resulting in their departure from the treated soils. High doses of biochar were able to cause death of red fire ants; the mortality rate of red fire ants reached 55.56% after 11 days of 20% biochar treatment. We also evaluated the effects of biochar on four behaviors of red fire ants, namely aggregation, walking, grasping, and attacking; 20% of the biochar treatment group reduced aggregation by 64.22% and this value was 55.22%, 68.44%, and 62.36% for walking, grasping, and attacking. Finally, we measured the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) enzyme activity and malondialdehyde (MDA) content in red fire ants; the results showed that the activities of the three enzymes increased with the increase in biochar addition, which indicated that a high dose of biochar induced oxidative stress in red fire ants. Our results indicate that biochar has the potential to cause toxicity and repel red imported fire ants (RIFAs) in a manner that is dependent on the concentration. We propose that biochar could be utilized in the control and manufacturing of baits for red fire ant management. This work establishes a foundation for the prevention and management of red fire ants and the logical utilization of biochar. [ABSTRACT FROM AUTHOR]

The injudicious and excessive use of synthetic pesticides has deleterious effects on humans, ecosystems, and biodiversity. As an alternative to traditional crop-protection methods, botanical pesticides are gaining importance. In this research endeavor, we examined the contact toxicity, knockdown time, lethal time, and toxicity horizontal transmission of three natural pesticides from plants (azadirachtin, celangulin, and veratramine) on red imported fire ants (RIFA; Solenopsis invicta). Our research findings indicated that azadirachtin and celangulin exhibited relatively high toxicity, with median lethal dose (LD50) values of 0.200 and 0.046 ng/ant, respectively, whereas veratramine exhibited an LD50 value of 544.610 ng/ant for large workers of S. invicta at 24 h post-treatment. Upon treatment with 0.125 mg/L, the (median lethal time) LT50 values of azadirachtin and celangulin were determined to be 60.410 and 9.905 h, respectively. For veratramine, an LT50 value of 46.967 h was achieved after being tested with 200 mg/L. Remarkably, azadirachtin and celangulin were found to exhibit high horizontal transfer among RIFA, with high secondary mortality (100%) and tertiary mortalities (>61%) after 48 h of treatment with 250 mg/L, as well as with their dust formulations for 72 h. However, veratramine did not exhibit significant toxicity or horizontal transfer effects on RIFA, even at high concentrations. These findings suggest that azadirachtin and celangulin are likely to have a highly prominent potential in the management of S. invicta. [ABSTRACT FROM AUTHOR]

This publication highlights the presence, damage, and management of imported fire ants in industrial hemp production. This UF/IFAS Extension publication offers practical knowledge to researchers, Extension agents, growers, crop consultants, agricultural professionals, and students on the effects and management of imported fire ants in industrial hemp production. Written by Nkem J. Nwosu, Hardeep Singh, Zachary Brym, Lakesh Sharma, Ethan Carter, Alexandra M. Revynthi, and Lance Osborne, and published by the UF/IFAS Agronomy Department, May 2024.

Ants of the genus Solenopsis are highlighted as the potential nest predators of many crocodilian species. During a study on the aspects of the natural history of the broad-snouted caiman in a protected area of Atlantic Rainforest in Pernambuco, North-eastern Brazil, a predation event was documented during nest visiting activities related to reproduction monitoring. The predation of a Caiman latirostris neonate by red fire ants Solenopsis sp. was observed, a dead neonate C. latirostris hatchling was found partially out of its shell, soon after hatching, still in the nest and covered in red fire ants. [ABSTRACT FROM AUTHOR]

Based on the biological characteristics of Solenopsis invicta and the structural characteristics of its ant nest, a fast and efficient closed treatment device was developed. Compared with the simple chemical treatment commonly used at present, the developed treatment device (the ant nest control cover) is a fast and efficient method to exterminate S. invicta in 7 d, featured by short course, quick results and good effect. [ABSTRACT FROM AUTHOR]

Essential oils from five Baccharis species were screened for their toxicity and biting deterrence/repellency against yellow fever mosquito, Aedes aegypti (L.), and imported fire ants, including Solenopsis invicta Buren (RIFA), Solenopsis richteri Forel (BIFA) and their hybrids (HIFA). Baccharis microdonta DC. and B. punctulata DC. at 10 µg/cm2 showed biting deterrence similar to DEET, N, N-diethyl-meta-toluamide at 25 nmol/cm2, whereas the repellency of B. pauciflosculosa DC., B. sphenophylla Dusén ex Malme and B. reticularioides Deble & A.S. Oliveira essential oils was significantly lower than DEET against mosquitoes. Two major compounds from the active essential oils, kongol and spathulenol, also exhibited biting deterrence similar to DEET against mosquitoes. The highest toxicity exhibited against mosquitoes was by Baccharis punctulata essential oil (LC50 = 20.4 ppm), followed by B. pauciflosculosa (LC50 = 31.9 ppm), B. sphenophylla (LC50 = 30.8 ppm), B. microdonta (LC50 = 28.6 ppm), kongol (LC50 = 32.3 ppm), spathulenol (LC50 = 48.7 ppm) and B. reticularioides essential oil (LC50 = 84.4 ppm). Baccharis microdonta essential oil showed repellency against RIFA, BIFA and HIFA at 4.9, 4.9 and 39 µg/g, respectively. Baccharis microdonta essential oil also showed toxicity with LC50 of 78.9, 97.5 and 136.5 µg/g against RIFA, BIFA and HIFA, respectively, at 24 h post treatment.

This paper presents numeric morphology-based evidence on the broadly overlapping distribution of two thief ant species Solenopsis fugax (Latreille, 1798) and S. juliae (Arakelian, 1991) in the East European Pontic-Caspian region. The paper integrates two autonomous data collections and independent analyses performed by different researchers, using different equipment, considering different character combinations, and evaluating partially different samples. Five type series, the neotype series of Solenopsis fugax (Latreille 1798) and the type series of S. flavidula (Nylander, 1849), S. (Diplorhoptrum) fugax var. furtiva Santschi, 1934, S. (Diplorhoptrum) fugax var. pontica Santschi, 1934, S. (Diplorhoptrum) fugax var. scytica Santschi, 1934 were nested in one cluster and we propose the junior synonymy of the latter four taxa names with S. fugax. The other cluster contained only one type specimen of Solenopsis nitida (Dlussky & Radchenko, 1994) measured from AntWeb images. The naming of this cluster was based on both verbal statements and measurements of gynes given in the original description of Solenopsis juliae (Arakelian, 1991), which represents the oldest available name for this cluster. Hence, S. nitida is proposed as junior synonym of S. juliae. Solenopsis cypridis Santschi, 1934 is raised to species rank based on investigation of worker and gyne type specimens. [ABSTRACT FROM AUTHOR]

The red imported fire ant (Solenopsis invicta Buren) is a social pest species with a robust reproductive ability that causes extensive damage. Identification of the genes involved in queen fertility is critical in order to better understand the reproductive biology and screening for the potential molecular targets in S. invicta. Here, we used the mRNA deep sequencing (RNA-seq) approach to identify differentially expressed genes (DEGs) in the transcriptomes of three reproductive caste types of S. invicta, including queen (QA) and winged female (FA) and male (MA) ants. The genes that were specific to and highly expressed in the queens were then screened, and the Vg2 and Vg3 genes were chosen as targets to explore their functions in oogenesis and fertility. A minimum of 6.08 giga bases (Gb) of clean reads was obtained from all samples, with a mapping rate > 89.78%. There were 7524, 7133, and 977 DEGs identified in the MA vs. QA, MA vs. FA, and FA vs. QA comparisons, respectively. qRT–PCR was used to validate 10 randomly selected DEGs, including vitellogenin 2 (Vg2) and 3 (Vg3), and their expression patterns were mostly consistent with the RNA-seq data. The S. invicta Vgs included conserved domains and motifs that are commonly found in most insect Vgs. SiVg2 and SiVg3 were highly expressed in queens and winged females and were most highly expressed in the thorax, followed by the fat body, head, and epidermis. Evaluation based on a loss-of-function-based knockdown analysis showed that the downregulation of either or both of these genes resulted in smaller ovaries, less oogenesis, and less egg production. The results of transcriptional sequencing provide a foundation for clarifying the regulators of queen fertility in S. invicta. The functions of SiVg2 and SiVg3 as regulators of oogenesis highlight their importance in queen fecundity and their potential as targets of reproductive disruption in S. invicta control. [ABSTRACT FROM AUTHOR]

Essential oils from five Baccharis species were screened for their toxicity and biting deterrence/repellency against yellow fever mosquito, Aedes aegypti (L.), and imported fire ants, including Solenopsis invicta Buren (RIFA), Solenopsis richteri Forel (BIFA) and their hybrids (HIFA). Baccharis microdonta DC. and B. punctulata DC. at 10 µg/cm2 showed biting deterrence similar to DEET, N, N-diethyl-meta-toluamide at 25 nmol/cm2, whereas the repellency of B. pauciflosculosa DC., B. sphenophylla Dusén ex Malme and B. reticularioides Deble & A.S. Oliveira essential oils was significantly lower than DEET against mosquitoes. Two major compounds from the active essential oils, kongol and spathulenol, also exhibited biting deterrence similar to DEET against mosquitoes. The highest toxicity exhibited against mosquitoes was by Baccharis punctulata essential oil (LC50 = 20.4 ppm), followed by B. pauciflosculosa (LC50 = 31.9 ppm), B. sphenophylla (LC50 = 30.8 ppm), B. microdonta (LC50 = 28.6 ppm), kongol (LC50 = 32.3 ppm), spathulenol (LC50 = 48.7 ppm) and B. reticularioides essential oil (LC50 = 84.4 ppm). Baccharis microdonta essential oil showed repellency against RIFA, BIFA and HIFA at 4.9, 4.9 and 39 µg/g, respectively. Baccharis microdonta essential oil also showed toxicity with LC50 of 78.9, 97.5 and 136.5 µg/g against RIFA, BIFA and HIFA, respectively, at 24 h post treatment. [ABSTRACT FROM AUTHOR]

Simple Summary: The division of labor among workers is one of the predominant characteristics of social insects, which simply means that workers perform different tasks, such as caring for the brood inside the nest and foraging outside the nest, and which is essential for colony maintenance and development. Previous studies on honeybees have demonstrated that the regulation of behavioral transitions can be influenced by juvenile hormone (JH). The red imported fire ant (RIFA), Solenopsis invicta, is a typical social pest that poses a significant risk to biodiversity, ecosystems, and public health in invaded areas. Understanding the effects of JH on the behavioral transitions of RIFA is necessary, as it may provide valuable experimental data for pest control. In this study, we simulated JH elevation using the juvenile hormone analogue (JHA) methoprene application and evaluated its effect on activity levels, brood care behavior, phototaxis, and threat responsiveness of nurse workers. Our study indicates that the application of JHA reduced brood care behavior and enhanced phototaxis in nurse workers, thereby revealing the role of JH in facilitating behavioral transitions in RIFA from intranidal tasks to extranidal activity. These findings may contribute to a better understanding of the underlying mechanisms behind the division of labor in social insects. The division of labor among workers is a defining characteristic of social insects and plays a pivotal role in enhancing the competitive advantage of their colony. Juvenile hormone (JH) has long been hypothesized to be the essential driver in regulating the division of labor due to its ability to accelerate behavioral transitions in social insects, such as honeybees. The regulation of behavioral transitions by JH in the red imported fire ant (RIFA), Solenopsis invicta, a typical social pest, is unclear. Through video capture and analysis, we investigated the effects of the juvenile hormone analogue (JHA) methoprene on brood care, phototaxis behavior, and threat responsiveness of RIFA nurse workers. Our results showed that the JHA application significantly reduced the time and frequency of brood care behavior by nurse workers while increasing their walking distance and activity time in the light area. Additionally, the application of JHA made ants become excited, indicating a significant improvement in their activity level (movement distance, time, and speed). Furthermore, it was observed that the application of JHA did not affect the threat responsiveness of nurse workers towards stimuli (nestmates or non-nestmates). Our study demonstrates that the application of JHA reduced brood care behavior and enhanced phototaxis in nurse workers, which may reveal the role of JH in facilitating behavioral transitions in RIFA from intranidal tasks to extranidal activity. This study provides an experimental basis for further elucidating the mechanism underlying the division of labor in social insects. [ABSTRACT FROM AUTHOR]

Simple Summary: The Black Imported Fire Ant, Solenopsis richteri, was accidentally introduced to the southern U.S. in the 1930s from South America. Long-term, sustained suppression approaches through biological control are needed to control growing invasive fire ant populations. Among the natural enemies used in the U.S., there have been multiple releases of a fungal-like microsporidian pathogen, Kneallhazia solenopsae. In this study, researchers characterized the prevalence and genetic diversity of this microsporidium in native populations of S. richteri. The goal of these types of studies is to assess how the natural enemy acts in the native environment to improve biological control methods. The researchers analyzed ants from 219 nests and found that the microsporidium was present in 12.8% of the nests. Interestingly, within these S. richteri colonies, researchers found a social parasitic ant, Solenopsis daguerrei, and when those ants were analyzed, 3.9% of S. daguerrei ants tested positive for the microsporidium. The microsporidian variants found in both Solenopsis species were genetically similar. Further studies are needed to evaluate the pathogenicity of this microsporidian variant. Microsporidia are natural pathogens of arthropods and have been used as biological control against insect pests. In the United States, efforts to control the invasive Red Imported Fire Ant, Solenopsis invicta, and Black Imported Fire Ant, Solenopsis richteri, have included the use of the microsporidium, Kneallhazia solenopsae. However, there is limited information about the genetic differences among the microsporidian variants found in S. invicta and in S. richteri. In this study, we assessed the prevalence and genetic diversity of K. solenopsae in native populations of S. richteri in Argentina (South America). Additionally, we examined the social parasitic ant, Solenopsis daguerrei, which is found in some S. richteri nests, for the presence of this microsporidium. The survey of 219 S. richteri nests revealed K. solenopsae infections in all five sites analyzed, with 28 colonies (12.8%) positive for the microsporidium. Among the 180 S. daguerrei individuals collected, seven ants (3.9%) from three sites tested positive for K. solenopsae. Phylogenetic analyses of the microsporidian variants present in S. richteri and S. daguerrei based on partial small subunit ribosomal gene sequences (SSU rRNA) showed that both ant species shared the same variant, which is different from the ones found in S. invicta. Further studies are needed to determine the pathogenicity of genetically different K. solenopsae variants among Solenopsis species. [ABSTRACT FROM AUTHOR]

BACKGROUND: Agricultural pests have caused huge losses in agricultural production and threaten global food security. Synthetic insecticides remain the major control method. However, with the rapid development of pest resistance and the increasingly stringent regulations on pesticide usage, the development of efficient insecticides with novel structures is particularly urgent. RESULTS: Twenty‐six novel anthranilic diamide derivatives containing the thiazole moiety were designed based on the scaffold hopping strategy. Bioassay results indicated that compound 6e exhibited excellent insecticidal activity against a susceptible strain of diamondback moth (Plutella xylostella) with a median lethal concentration (LC50) of 0.65 mg L−1, which was similar to chlorantraniliprole (LC50 = 0.53 mg L−1). Compound 6e showed marginally lower (LC50 = 50.45 mg L−1) insecticidal activity than chlorantraniliprole (LC50 = 31.98 mg L−1) on chlorantraniliprole‐resistant P. xylostella larvae, suggesting a cross‐resistance of compound 6e with chlorantraniliprole (resistance ratios, 77.6‐fold and 60.3‐fold, respectively). Compound 6e also showed good insecticidal activity against fall armyworm and beet armyworm with pest mortalities of 74% and 64%, respectively, at 5 mg L−1 concentration. In addition, compounds 6e and 12a showed delayed toxicity against red imported fire ant with mortality rates of 84% and 85% (respectively) after 5 days of treatment at 1.0 mg L−1, which were superior to that of chlorantraniliprole. CONCLUSION: The introduction of thiazole into anthranilic diamide scaffolds resulted in insecticidal leads 6e and 12a with excellent insecticidal activities and potential application in controlling red imported fire ants. The work also guides the discovery of insecticidal molecules with thiazole‐containing anthranilic diamide scaffold. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: In social insects, the labor division of workers is ubiquitous and controlled by genetic and environmental factors. However, how they modulate this coordinately remains poorly understood. RESULTS: We report miR‐279c‐5p participation in insulin synthesis and behavioral transition by negatively regulating Rab8A in Solenopsis invicta. Eusocial specific miR‐279c‐5p is age‐associated and highly expressed in nurse workers, and localized in the cytoplasm of neurons, where it is partly co‐localized with its target, Rab8A. We determined that miR‐279c‐5p agomir suppressed Rab8A expression in forager workers, consequently decreasing insulin content, resulting in the behavioral shift to 'nurse‐like' behaviors, while the decrease in miR‐279c‐5p increased Rab8A expression and increased insulin content in nurse workers, leading to the behavioral shift to 'foraging‐like' behaviors. Moreover, insulin could rescue the 'foraging behavior' induced by feeding miR‐279c‐5p to nurse workers. The overexpression and suppression of miR‐279c‐5p in vivo caused an obvious behavioral transition between foragers and nurses, and insulin synthesis was affected by miR‐279c‐5p by regulating the direct target Rab8A. CONCLUSION: We first report that miR‐279c‐5p is a novel regulator that promotes labor division by negatively regulating the target gene Rab8A by controlling insulin production in ants. This miRNA‐mediated mechanism is significant for understanding the behavioral plasticity of social insects between complex factors and potentially provides new targets for controlling red imported fire ants. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

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Division of labor is a hallmark characteristic of social insect colonies. While it is understood that worker differentiation is regulated through either the queen or her brood, the understanding of the physiology behind task regulation varies within social species. Studies in eusocial insects have shown that juvenile hormone (JH) is associated with division of labor and the onset of foraging tasks. Although, outside of a few key species, this interaction has yet to be elucidated in the red imported fire ant, Solenopsis invicta. In this study, we evaluated the role of a JH analog, S-hydroprene in worker task transition in Solenopsis invicta. S-hydroprene was applied to nurses to observe behavioral changes. S-hyroprene application to nurses did not affect phototaxis, but there was a shift in behavior from internal, nest-based behaviors to external, foraging-based behaviors. These results show that JH may be implicated in worker task transition in S. invicta and may function similarly as it does in other eusocial insects. [ABSTRACT FROM AUTHOR]

Red imported fire ants (Solenopsis invicta; fire ants) are an invasive species that prey on arthropods in the southern United States. Researchers examined using fire ants to control agricultural Lepidoptera pests, but minimal research has investigated the effects of fire ants on the broader butterfly community. Three ranches in Texas, USA, with known fire ant occurrence underwent treatment to remove fire ants, creating a treated section and an untreated section for each ranch. We sampled sites using colored pan traps 3 times per sampling period during 2018 and 2019. Over 2 years, we collected 1,262 butterflies across 28 species in pan traps. Average butterfly abundance was higher in treated sites than untreated sites. The majority of species collected were in the family Hesperiidae, followed by the Pieridae family. We found Hesperiidae species more often in blue pan traps and Pieridae species more often in yellow pan traps. Butterfly species that overwinter as immature stages were more abundant in treated sites than in untreated sites, which suggests there could be a connection between fire ant presence and mortality of overwintering immature stages. Our results suggest that fire ants may negatively affect butterfly communities and differentially affect certain species. Additional research is needed to understand the effects of fire ants on butterflies and the overall pollinator community, and the effectiveness of pan traps for surveying Lepidoptera. [ABSTRACT FROM AUTHOR]

Simple Summary: Both field and laboratory studies showed that 0.0125% fipronil bait is repellent against S. invicta workers; therefore, higher concentrations of fipronil should be avoided in fire ant bait production. In future studies evaluating the effectiveness of fire ant baits, we suggest considering the effect of active ingredients and their concentrations on bait acceptance. The red imported fire ant, Solenopsis invicta Buren, is a severe pest with agricultural, ecological, and medical significance. The baiting treatment is one of the main methods to control S. invicta. However, few studies have evaluated the acceptance of fire ant bait. Here, field and laboratory studies were conducted to investigate the foraging behaviors of S. invicta responding to fire ant baits containing different concentrations of active ingredients (fipronil, abamectin, or indoxacarb). Field studies showed that S. invicta transported significantly less 0.0125% fipronil bait than control bait (without toxicant) and 0.0001% fipronil bait. The number of foraging ants significantly decreased with an increase in fipronil concentration. Our previous study showed that S. invicta usually buries the food treated with repellent chemicals, and interestingly, significantly more soil particles were transported into tubes containing 0.0001% fipronil bait than tubes containing control bait or 0.0125% fipronil bait. In addition, S. invicta transported significantly less 0.0005% abamectin bait than control bait, and significantly fewer ants were found in tubes containing 0.0125% abamectin bait than control bait. However, there was no significant difference in bait transport, number of foraging ants, and weight of soil particles relocated in tubes containing different concentrations of indoxacarb bait. In addition, laboratory studies showed that S. invicta transported significantly less 0.0125% fipronil bait than control bait and bait containing abamectin (0.0025% or 0.0125%) or indoxacarb (0.0125% or 0.0625%). In addition, the transport speed for the 0.0125% fipronil bait was the slowest. These results show that specific concentrations of some active ingredients may negatively affect bait acceptance for S. invicta, and should be avoided in fire ant bait production. [ABSTRACT FROM AUTHOR]

The red imported fire ant (RIFA), Solenopsis invicta, is an invasive pest that causes damage to agricultural and ecological environments worldwide. Fluralaner is a new isoxazoline pesticide with the potential to become a control agent against RIFA. However, it is not clear whether S. invicta responds the same way to fluralaner at different reproductive stages. The present study firstly evaluated the toxicity of fluralaner to S. invicta at different developmental stages, finding that fourth instar larvae (LD50, 1744.23 mg/kg) and worker ants (LD50, 8.62 mg/kg) were differently susceptible to fluralaner, while the mortality rate of fourth instar larvae was significantly lower at the same concentration of 10 mg/L (5.56 ± 3.14%) than that of worker ants (62.22 ± 3.14%), demonstrating a greater tolerance to fluralaner. Subsequently, the metabolic responses of worker and larval ants to fluralaner stress (10 mg/L) were investigated using non-targeted metabolomics, which indicated that the amount of differential metabolites and the KEGG metabolic pathways enriched were different between workers and larvae when exposed to the same dose (10 mg/L) of fluralaner. Differential metabolites of larvae and worker ants under fluralaner stress were mainly concentrated in organic acids and their derivatives, lipids and lipid-like molecules, nucleosides, nucleotides, and analogues, combined with the enriched metabolic pathways, revealed that the differential metabolic responses of larvae and worker ants were mainly in energy metabolism, detoxification metabolism, and neurotransmitter ligands. Workers consumed more substrates in the arginine synthesis pathway (l-glutamic acid, l-aspartic acid, and fumaric acid) to provide energy for the detoxification (glutathione) of pesticides when exposed to fluralaner stress, and the high accumulation of l-aspartic acid induced excitotoxicity in the worker ants. Larval ants consumed more arachidonic acid to synthesize PG D2, and changes in the metabolism of antioxidants such as catechins, hesperidin, and l-ascorbic acid suggested that larvae were more capable of scavenging the ROS response than worker ants. The results of non-targeted metabolomics successfully revealed differences in the sensitivity of larvae and workers to fluralaner agents, providing insights into the fluralaner control of Solenopsis invicta. [ABSTRACT FROM AUTHOR]

Here we report the establishment in Hawai'i of a trap-jaw ant, Odontomachus ruginodis, a species well known for its potent sting. In June 2017, a farmer on the island of Kaua'i reported "bites" from large ants and supplied a specimen to the U.S. Fish and Wildlife Service for identification. Additional specimens were found in 2019 and 2020 in multiple locations up to 5 kilometres away from the initial detection. Multiple morphological identifications were made and combined with CO1 genetic assessment confirmed the species to be Odontomachus ruginodis, which had not been recorded prior from Hawai'i. We argue that greater biosecurity protocols are needed in Hawai'i to prevent further incursions, especially the introduction of the red imported fire ant, Solenopsis invicta. [ABSTRACT FROM AUTHOR]

Background: Entomopathogenic nematodes (EPNs) in an aqueous suspension treatment showed potential in the biocontrol of the red imported fire ant Solenopsis invicta, whereas colony relocation following this inundative application had restricted overall effectiveness. As a novel strategy, EPN pre‐infected insect cadavers carrying the next generation of nematode‐infective juveniles (IJs) might be used to efficiently manage insect pests. However, this strategy has not been tested on S. invicta. This study evaluated EPNs emerging from wax moth Galleria mellonella cadavers to facilitate infection of S. invicta compared to those used in aqueous suspensions. Results: Among seven EPN species, Steinernema riobrave and Heterorhabditis bacteriophora had the highest insecticidal efficiency in aqueous treatment. Cadavers of G. mellonella colonized by either one of two EPN species were not damaged by worker ants, ensuring that the IJs could develop within and emerge successfully from the cadavers. Likewise, compared to an aqueous suspension treatment with an equivalent number of IJs, treatment with an S. riobrave‐infected cadaver increased the mortality of S. invicta by ≈10%, whereas infection by H. bacteriophora did not differ between treatments. However, the coexistence of S. riobrave‐ and H. bacteriophora‐infected cadavers adversely affected the control of S. invicta, likely as a result of competition resulting from the increased dispersal of each emerging EPN species. Conclusion: Using EPN‐infected G. mellonella cadavers as a strategy increased the mortality of S. invicta in the laboratory. This study provides positive evidence for the future applications of S. riobrave‐infected cadavers in the biocontrol of red imported fire ants. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The little fire ant Wasmannia auropunctata (Roger) is a major invasive species that seriously threatens the biodiversity of invaded areas. W. auropunctata was first reported in Chinese mainland in 2022 and its impact on native species is still unknown. To evaluate the impact of W. auropunctata invasion on the ant communities in southern China, a series of interspecific competition experiments were conducted in this study. The individual aggression index and group aggression experiments showed the advantage of W. auropunctata in competition with 5 resident ants under equal worker numbers. When encountering Anoplolepis gracilipes, Camponotus nicobarensis, Tetramorium bicarinatum, Polyrhachis dives, and Solenopsis invicta, W. auropunctata gradually gained a competitive advantage with an increase in its number of workers. In the group aggression experiments with equal worker numbers, there was a negative correlation between the body length and mortality rate of resident ants. The results of the foraging behavior experiments showed that W. auropunctata was able to dominate food resources under competition with Carebara diversa, which also displayed weak competition in the group aggression bioassay. In addition, the abilities to recruit workers and retrieve food were inhibited under competition with S. invicta and T. bicarinatum. The results of the nesting behavior experiments showed that in the 24‐h bout of space resource competition, W. auropunctata was dominant over C. diversa, S. invicta, and T. bicarinatum. The results of this study show that W. auropunctata has certain advantages in competition for food and space resources over resident ants in southern China, and some resident ant species may be replaced in the future. [ABSTRACT FROM AUTHOR]

Simple Summary: Imported fire ants are significant pests of urban, agricultural, and medical importance, causing USD billions of annual losses in the United States. Synthetic insecticides are commonly used in their management. The potential adverse effects of synthetic insecticides highlight the need to develop natural-product-based alternatives for fire ant control. Repellants are useful in managing fire ants; for example, repellants can be used to prevent fire ants from invading sensitive areas, such as electrical equipment, nursing homes, and hospitals. In particular, plant-derived natural repellants may provide a safer and more environmentally friendly alternative. This study demonstrates the repellent effects of the plant-essential-oil-derived compounds carvacrol, thymol, and their acetate derivatives against imported fire ants. Carvacrol, a GRAS compound (Generally Recognized As Safe) was the most potent repellent against red, black, and imported fire ants with minimum repellent effective doses of 0.98 µg/g, 7.80 µg/g, and 0.98 µg/g, respectively, followed by thymol, carvacrol acetate, and thymol acetate. Thymol red essential oil containing carvacrol and thymol also showed repellency. These results indicated that carvacrol and thymol as well as essential oils with high contents of carvacrol and/or thymol are potentially useful in managing imported fire ants. In the United States, imported fire ants are commonly referred to as red imported fire ants (Solenopsis invicta Buren), black imported fire ants (S. richteri Forel), and hybrid imported fire ants (S. invicta × S. richteri). They are significant pests, and their control heavily relies on synthetic insecticides. The extensive use of insecticides has led to public concern about their potential negative effects on human health and the well-being of wildlife and the environment. As an alternative, plant-derived natural compounds, particularly essential oils (EOs) and their main constituents, show promise as safe and environmentally friendly products for controlling fire ants. Repellants are useful in managing fire ants, and plant-derived natural repellants may serve as a safer and more environmentally friendly option. This study investigates the repellency of EO-derived compounds carvacrol, thymol, and their acetates against imported fire ant workers. The results revealed that carvacrol, a GRAS compound (Generally Recognized As Safe), was the most potent repellent against S. invicta, S. richteri, and their hybrid, with minimum repellent effective doses (MREDs) of 0.98 µg/g, 7.80 µg/g, and 0.98 µg/g, respectively. Thymol also exhibited strong repellency, with MREDs of 31.25 µg/g, 31.25 µg/g, and 7.8 µg/g, respectively. Furthermore, thyme-red essential oil, characterized by a thymol chemotype containing 48.8% thymol and 5.1% carvacrol, was found to effectively repel the hybrid ants with an MRED of 15.6 µg/g. In contrast, thyme essential oil, characterized by a linalool chemotype lacking thymol and carvacrol, did not exhibit any repellent effect, even at the highest tested dose of 125 µg/g. This study provides the first evidence of the potent repellency of carvacrol and thymol against imported fire ant workers, indicating their potential as promising repellents for fire ant control. [ABSTRACT FROM AUTHOR]

Simple Summary: Deformed wing virus (DWV) is a major honey bee pathogen found throughout the world. DWV, in association with the varroa mite, causes wing deformity, a shortened abdomen, and neurological impairments, leading to the mortality of millions of honey bee colonies worldwide. At least 12 ant species have been shown to harbor DWV, including the red imported fire ant, one of the most invasive and detrimental pests in the world. To date, there have been no reports in the literature of DWV causing symptoms in ants. In this study, we observed the classic honey-bee-like symptoms of deformed wings in laboratory and field colonies of the red imported fire ants and verified the presence and replication of DWV. This is the first report of the co-occurrence of DWV-like symptoms and DWV in ants. However, more research is needed to determine whether DWV is indeed the causative agent of DW syndrome in S. invicta. Deformed wing virus (DWV), a major honey bee pathogen, is a generalist insect virus detected in diverse insect phyla, including numerous ant genera. Its clinical symptoms have only been reported in honey bees, bumble bees, and wasps. DWV is a quasispecies virus with three main variants, which, in association with the ectoparasitic mite, Varroa destructor, causes wing deformity, shortened abdomens, neurological impairments, and colony mortality in honey bees. The red imported fire ant, Solenopsis invicta Buren, is one of the most-invasive and detrimental pests in the world. In this study, we report the co-occurrence of DWV-like symptoms in S. invicta and DWV for the first time and provide molecular evidence of viral replication in S. invicta. Some alates in 17 of 23 (74%) lab colonies and 9 of 14 (64%) field colonies displayed deformed wings (DWs), ranging from a single crumpled wing tip to twisted, shriveled wings. Numerous symptomatic alates also exhibited altered locomotion ranging from an altered gait to the inability to walk. Deformed wings may prevent S. invicta alates from reproducing since mating only occurs during a nuptial flight. The results from conventional RT-PCR and Sanger sequencing confirmed the presence of DWV-A, and viral replication of DWV was confirmed using a modified strand-specific RT-PCR. Our results suggest that S. invicta can potentially be an alternative and reservoir host for DWV. However, further research is needed to determine whether DWV is the infectious agent that causes the DW syndrome in S. invicta. [ABSTRACT FROM AUTHOR]

1. Non‐native species may be the cause of native species declines or an effect of habitat degradations that promote the former and damage the latter. Social insects are extraordinarily successful organisms, and non‐native social insects, such as ants, often are very successful invaders of novel habitats. 2. The red imported fire ant (Solenopsis invicta) and the Asian needle ant (Brachyponera chinensis) are widespread non‐native invaders in the eastern United States that bring ecological, economic and social impacts, but their putative effects on native ant communities may be concomitant with habitat degradation rather than inherent in their invasion. 3. Given this gap in understanding, our goal was to examine how experimental warming influenced native and non‐native ant communities. Specifically, we hypothesised that (a) non‐native ant abundance and species richness will increase in warmed plots and that (b) warming‐induced increases in the non‐native ant populations will correspond with decreases in native ant abundance and species richness. 4. To test these hypotheses, we used three levels of experimental forest edge soil warming (warming targeted at +0, +3, and +5°C above ambient soil temperature) in a mixed deciduous forest in the Georgia (USA) Piedmont. We used repeated pitfall trapping to investigate how the experimental warming influenced the composition of native and non‐native ant communities with a focus on how warming combined with S. invicta and B. chinensis invasion impacted native ant communities. 5. Our results suggest that experimental warming promoted the non‐native invasive ants, particularly S. invicta and B. chinensis. We also found that B. chinensis somewhat inhibited native ant communities, but not because of warming. The warmed environment benefited both non‐native invasive ants at the expense of native ants but, given that B. chinensis negatively impacted the native ants with far fewer workers than S. invicta, B. chinensis may pose a greater threat to native ant communities than S. invicta in a warmer world. [ABSTRACT FROM AUTHOR]

The article discusses the challenges posed by invasive alien species (IAS) and their impact on biodiversity, food production, ecosystems, and human health. It highlights the case of the tomato leaf miner in China, which has caused significant economic losses. The article also mentions the global extent of IAS and their negative effects on nature and quality of life. It emphasizes the need for effective management strategies, including prevention, eradication, containment, and control. The article concludes by calling for increased awareness, research, and international cooperation to address the threat of IAS and protect biodiversity and human well-being. [Extracted from the article]