Yijuan Xu

South China Agricultural University · Department of Entomology

The gut microbiota of insects has been shown to regulate host detoxification enzymes. However, the potential regulatory mechanisms involved remain unknown. Here, we report that gut bacteria increase insecticide resistance by activating the cap “n” collar isoform-C (CncC) pathway through enzymatically generated reactive oxygen species (ROS) in Bactr...

The invasion of exotic ant species in China presents significant challenges to ecosystems, agriculture, and the economy. This paper provides an in-depth analysis of China's ongoing battle with exotic ants, examining the factors contributing to their introduction and establishment. It explores the responses implemented by the decision makers, includ...

In the original publication [...]

The big-headed ant, Pheidole megacephala (Fabricius), has a widespread distribution across numerous regions globally. The International Union for Conservation of Nature (IUCN) has identified it as one of the 100 worst invasive alien species worldwide, given the severe ecological and economic harm it causes in invaded areas. In this study, we predic...

Various techniques used by crop plants to evade insect pests and pathogen attacks have been documented. Among these, plant defense strategies induced by endophytic insect pathogenic fungi are arguably one of the most discussed. Endophytic fungi frequently colonize plants and inhabit their internal tissues for a portion of their lifespan without pro...

Simple Summary Interactions between insects and symbiotic bacteria affect the behavior or biological characteristics of host insects, which in turn affect the intraspecific and interspecific relationships of insects. In this paper, we review multi-trophic interactions among symbiotic bacteria, insects, and their mutualistic partners, and the known...

Red imported fire ants mounds have been suggested as a potential reservoir for beneficial entomopathogenic fungal species that are vital for more complex roles in the ecosystem aside from infecting the insects. In the current study, the assemblage of fungal symbionts of the red imported fire ants (RIFA) were obtained across five cities in Guangdong...

Soil microbes have a wide range of distribution across the world and can be found in different agricultural and forest systems including cultivated soils, ant mounds, decaying trees, leaves, roots, and on insect bodies. Across five counties of Guangdong province of China, the assemblage of bacterial associates of red imported fire ant (RIFA) were e...

Threatening the global community is a wide variety of potential threats, most notably invasive pest species. Invasive pest species are non-native organisms that humans have either accidentally or intentionally spread to new regions. One of the most effective and first lines of control strategies for controlling pests is the application of insectici...

Gut symbiotic bacteria are known to be closely related to insect development, nutrient metabolism, and disease resistance traits, but the most important factors leading to changes in these communities have not been well clarified. To address this, we examined the associations between the gut symbiotic bacteria and the host genotype and geographical...

Fungus‐growing termites cultivate the fungal mutualist Termitomyces as their main food source; however, how fungus‐growing termites protect Termitomyces from threats is still unclear. In this study, we investigated the actinobacterial communities in Odontotermes formosanus individuals and their fungal combs. Moreover, the antifungal activities of t...

Over a long period of evolution, insects have developed unique intestinal defenses against invasion by foreign microorganisms, including physical defenses and immune responses. The physical defenses of the insect gut consist mainly of the peritrophic matrix (PM) and mucus layer, which are the first barriers to pathogens. Gut microbes also prevent t...

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 se...

Invasive ants are some of the most destructive species in ecosystems and can have serious ecological and socioeconomic impacts. The little fire ant, Wasmannia auropunctata, is native to Central and South America and was listed as one of the 100 most threatening major invasive organisms in the world by the International Union for Conservation of Nat...

Insecticide resistance poses many challenges in insect pest control, particularly in the control of destructive pests such as red imported fire ants (Solenopsis invicta). In recent years, beta-cypermethrin and fipronil have been extensively used to manage invasive ants, but their effects on resistance development in S. invicta are still unknown. To...

Chemicals, including toxic bait and dusts, are the main means of controlling the red imported fire ant Solenopsis invicta (abbreviation ‘RIFA’), which is a serious invasive pest. To identify environmentally friendly chemicals for controlling RIFA, we tested the toxicity and horizontal transfer of three botanical insecticides—matrine, rotenone, and...

The cap ‘n’ collar isoform C (CncC) transcription factor is thought to be a regulator associated with antioxidant and detoxification genes that can enhance pest resistance by regulating the expression of detoxification enzyme genes. However, this transcription factor has not been well studied in the important agricultural pest Bactrocera dorsalis....

Observations have shown that seeds collected by harvester ants are less likely to mold. Based on evolutionary analysis and other research, it was hypothesized that harvester ants could apply actinomycetes to protect seeds, similar to the protection of mutualistic fungi by leafcutter ants. Two actinomycetes were successfully isolated from the harves...

The red imported fire ant (RIFA), Solenopsis invicta Buren, is an invasive pest species worldwide in many countries and regions. At present, its control mainly depends on synthetic insecticides. Although synthetic insecticides have the advantages of efficacy and convenience, their widespread use has a negative impact on the diversity of local arthr...

In January 2022, we received ant specimens collected from three field colonies from Shantou City, Guangdong Province, China. They were identified as the little fire ant, Wasmannia auropunctata, through morphological and molecular analyses. Wasmannia auropunctata is listed as one of the 100 most dangerous invasive species by the International Union...

Insect pests cause significant agricultural and economic losses to crops worldwide due to their destructive activities. Pesticides are designed to be poisonous and are intentionally released into the environment to combat the menace caused by these noxious pests. To survive, these insects can resist toxic substances introduced by humans in the form...

Frequent international trade has accelerated the invasion of alien species. However, data on the distribution of invasive species after their introduction and the factors that determine their geographical distribution are lacking. This study analyzes the distributional trends and their drivers of invasive species in China. In addition, 13 main inva...

The red imported fire ant (Solenopsis invicta) is one of the deadliest invasive ant species that threatens the world by disrupting biodiversity, important functions within a natural ecosystem, and community structure. They are responsible for huge economic losses in the infested countries every year. Synthetic insecticides, especially indoxacarb, h...

Human activity has facilitated the introduction of many exotic species via global trade. Asia-Pacific countries comprise one of the most economically and trade-active regions in the world, which makes it one of the most vulnerable regions to invasive species, including ants. There are currently over 60 exotic ant species in the Asia-Pacific, with t...

The paralysis behavior of some ponerine ants when foraging may be important for food storage and colony development. However, how workers invest in paralysis under different prey circumstances is often overlooked. Here, we report the prey-foraging behavior and paralysis behavior of Harpegnathos venator under different food supply conditions. Solita...

【Aim】 The aim of this study is to isolate microsatellite markers from Tapinoma melanocephalum genome, and to identify polymorphisms of the microsatellite loci. 【Methods】 We developed microsatellite loci from the genomes of 11 geographic populations of T. melanocephalum from the mainland and islands of South China via 454 GS FLX pyrosequencing techn...

The multiple roles of fungal entomopathogens in host plants' growth promotion, pest and pathogen management have drawn huge attention for investigation. Endophytic species are known to influence various activities of their associated host plants, and the endophyte-colonized plants have been demonstrated to gain huge benefits from these symbiotic as...

In the past few decades, the control of pests and diseases of cultivated plants using natural and biological measures has drawn increasing attention in the quest to reduce the level of dependence on chemical products for agricultural production. The use of living organisms, predators, parasitoids, and microorganisms, such as viruses, bacteria, and...

The objective of this study is to assess the diversity of bacteria in the venom glands of the red imported fire ant, Solenopsis invicta, and to compare the bacterial communities in the venom glands with those of other two stinging ants, Solenopsis geminata and Diacamma rugosum.

Biotic invasions can predominantly alter the dynamics, composition, functions, and structure of natural ecosystems. Social insects, particularly ants, are among the most damaging invasive alien species. Invasive ant species are among the supreme threats to ecosystems. There are about 23 species of invasive ants recorded worldwide, according to the...

Symbiotic bacterial communities that colonize the digestive tract of tephritid fruit flies interact with nutrient intake to improve the flies’ fitness and immunity. Some bacterial species consistently inhabit the tephritid guts and are transmitted to the next generation vertically. These species contribute significantly to some aspects of their hos...

Among fruits and fruit products, oranges and orange juice are the most widely consumed worldwide. However, the effects of pest infestation of oranges on the quality of orange juice are not yet known. To evaluate the effect of the oriental fruit fly Bactrocera dorsalis on the antioxidant activity of orange juice, we measured changes in the vitamin C...

Background Ant-microbe interactions that naturally occur in the venom microenvironment remain mostly unknown. To best of our knowledge, no research exists that shows the identity and diversity of bacterial communities in the fires ants, and what adaptive advantages that venom-associated microbes might offer to their hosts or that hosts might provid...

The use of insecticide remains the frontline method in controlling red imported fire ant (Solenopsis invicta Buren) (Hymenoptera: Formicidae), one of the worst invasive ants in the world. Neonicotinoids are effective ingredients in toxic baits for suppressing S. invicta population. To search for new and effective insecticides, the toxicity and subl...

Red imported fire ant, Solenopsis invicta, was first found in Taiwan province of China in 2003. To prevent transboundary expansion, the Chinese government has formulated various control strategies in the last 15 years to slow down the spread of S. invicta. Despite all efforts, S. invicta invasion has reached more than 390 counties of 13 provinces a...

Red imported fire ant, Solenopsis invicta , was first found in Taiwan province of China in 2003. To prevent transboundary expansion, the Chinese government has formulated various control strategies in the last 15 years to slow down the spread of S. invicta . Despite all efforts, S. invicta invasion has reached more than 390 counties of 13 provinces...

The red imported fire ant, Solenopsis invicta Buren, is a serious agricultural and public health pest in its introduced range. Several natural products have been tested to replace synthetic insecticides for the novel, economically feasible and environ-mentally friendly control of this pest. No information is available on the toxicity of vitamins to...

Globalization of trade and tourism has promoted the dispersal of exotic animals and plants around the world. Quantifying the invasion of exotic insects resulting from overseas trade is essential for national and international risk assessments. Seaports are important hubs for the arrival of exotic insects and a pathway for the invasion of alien spec...

Invasive ant species interact with both native and previously introduced ants in new environments. Their effects on resident species may vary warranting a careful examination of the possible mechanisms that govern these differences. We used individual and group aggression assays and an assay of walking speed to examine behavioral interactions betwe...

The ability of Aedes albopictus Skuse to transmit several pathogens to humans makes it a very important mosquito with public health significance. Ecofriendly products as alternatives to synthetic chemicals for the control of mosquito vectors are needed. Therefore, the larvicidal and repellent effects of two nontoxic chemicals, butyl anthranilate (BA)...

BACKGROUND The red imported fire ant, Solenopsis invicta, is one of the most dangerous invasive species in the world. Fire ants can spread by hiding among plant material and soil that are transported from infested areas in vehicles and vessels. Therefore, efficient repellents may be used to prevent fire ants from infesting transported goods. Althou...

Exotic invasive species can influence the behavior and ecology of native and resident species, but these changes are often overlooked. Here we hypothesize that the ghost ant, Tapinoma melanocephalum, living in areas that have been invaded by the red imported fire ant, Solenopsis invicta, displays behavioral differences to interspecific competition...

Red imported fire ant is an invasive species with the characteristics of quick dispersion, strong ferocity and aggression. For a long time, chemical control has been used as a main means of prevention and control of this pest, but the long-term use of high toxic pesticides will lead to a serious impact on the environment and non-target organisms. T...

The red imported fire ant, Solenopsis invicta, is a problematic invasive species in China since at least 2003. Over the past 15 years, a numerous studies were published on the impacts of this species on flora, fauna, and ecosystem function in natural and agricultural systems. We reviewed the literature on S. invicta invasion biology and impacts on...

The Oriental fruit fly, Bactrocera dorsalis (Hendel), is among the most destructive fruit/vegetable-eating agricultural pests in the world, particularly in Asian countries such as China. Because of its widespread distribution, invasive ability, pest status, and economic losses to fruit and vegetable crops, this insect species is viewed as an organi...

During the process of insect rearing and research, reliable insect escape prevention is indispensable. However, methods for preventing the escape of small insects, such as ants, remain limited. We used a mixture of talc powder and ethanol to prepare an anti-escape solution and compared its effects on Solenopsis invicta BUREN, 1972 and Monomorium in...

Fire ant venom contains insecticidal alkaloids named ‘solenopsins’. Whilst species-specific differences are reported, little attention has been given to caste-specific venom adaptations. The venom of fire ant queens has remained particularly poorly studied, though studies have shown it to be strikingly similar across different species, in being pri...

Fire ant venoms are composed of insecticidal alkaloids named 'solenopsins'. Whilst species-specific differences are reported, little attention was given to caste-specific venom adaptations. The venom of fire ants queens has remained poorly studied. Founding queens must succeed in isolation in the field, where venom is bound to play a role against c...

To understand whether flavor enhancers pose potential risks to the environment, it is important to assess its effects on insects. Therefore, the objective of this study was to evaluate the toxicity of flavor enhancers on the survival and behaviors of the red imported fire ant, Solenopsis invicta. In this study, we found that the mortality of S. inv...

The objective of this study was to evaluate the toxicity of flavor enhancers to the oriental fruit fly Bactrocera dorsalis (Hendel). The flavor enhancers glycine, disodium guanylate, succinic acid disodium salt, monosodium glutamate (MSG), disodium inosinate, and l-alanine significantly increased the mortality of B. dorsalis flies. The mortality of...

Susceptible individuals who have suffered painful stings caused by red imported fire ants, Solenopsis invicta, usually experience physical health effects such as fever, dizziness, generalized urticaria, or other systemic reactions such as anaphylactic shock. Whether S. invicta stings also have negative effects on mental health is not clear. In the...

Exemption determination request form-in Chinese. (JPG)

The human participant consent form-in Chinese. (DOCX)

Exemption determination request Form-English version. (DOCX)

Aim Tapinoma melanocephalum is listed as one of the most important invasive pest species in China. Information regarding the patterns of invasion and effects of geographic isolation on the population genetics of this species is largely lacking. Location South China. Methods To address this problem, we genotyped 39 colonies (two colonies were coll...

Solenopsis invicta , the red imported fire ant, represents one of the most devastating invasive species. To understand their sensory physiology, we identified and characterized their Hymenoptera-specific (Hs) TRPA channel, SiHsTRPA. Consistent with the sensory functions of SiHsTRPA, it is activated by heat, an electrophile, and an insect repellent....

Symbionts are associated with many insects and play several multifunctional roles in insect-microorganism mutualistic relationships. The trichlorphon-degrading symbiont Citrobacter freundii (CF-BD) of the oriental fruit fly Bactrocera dorsalis was recently discovered; however, its intraspecies transmission pathway among flies remains unknown. Here,...

The invention discloses a method for preventing small crawling insects such as ants from escaping by using an economical and convenient material and escape prevention liquid. The escape prevention liquid is prepared by mixing kaolin powder and a solvent (preferentially absolute ethyl alcohol) and is coated to the upper half portion of the inner wal...

The red imported fire ant, Solenopsis invicta Buren, is a serious agricultural, ecological, and public health pest in its invaded range. Chemical insecticides have been widely used for the prevention and control of this notorious pest. To search for novel, cost-effective, and environmentally friendly materials for fire ant control, we tested variou...

Background Symbiotic bacteria affect insect physiology and ecology. They may also mediate insecticide resistance within their hosts and thereby impact pest and vector control practices. Here, we document a novel mechanism of insecticide resistance in which a gut symbiont of the tephritid pest fruit fly Bactrocera dorsalis enhances resistance to the...

Background Geographic isolation is an important factor that limit species dispersal and thereby affects genetic diversity. Because islands are often small and surrounded by a natural water barrier to dispersal, they generally form discrete isolated habitats. Therefore, islands may play a key role in the distribution of the genetic diversity of inse...

Since the mid-1990s, many developed countries and regions experienced a resurgence of bed bugs. In this article, we reviewed the researches on bed bugs, including the resurgence causes, their biology and behavior, artificial rearing techniques, insecticide resistance, and monitoring and management techniques. We summarized the studies on the common...

The influence of conspecific interactions on behavior of individuals is an interesting topic, but with elusive proof. Here, we studied one species of ants Solenopsis invicta (social insects) and one species of tephritid fruit fly Bactrocera dorsalis (non-social insect) to determine whether lifespan of organisms could be affected by changes in the n...

Many ants are commonly infected by maternally inherited endosymbionts. We examined the prevalence of three bacterial endosymbionts (Wolbachia, Arsenophonus, and Cardinium) in ant populations in southern China. The results showed that the proportion of ant samples infected by Wolbachia and Arsenophonus was 30.20% and 18.79%, respectively. Cardinium...

This study used field trials to investigate how the fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae) affects the flower-visiting behavior of insects on rapeseed Brassica napus L. (Brassicales: Brassicaceae). Chemicals from fire ants were identified, and their electrophysiological effects on the cabbage white butterfly Pieris rapae (L.) (...

Factors promoting the invasion success of introduced populations have been receiving increased attention in studies of biological invasions. Previous reports have indicated that successful invasions may be attributable to reduced genetic diversity in the invasive species. However, there is large variation in the magnitude and direction of the impac...

The oriental fruit fly Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) causes serious damage that affects fruit production. Chemical insecticides have been widely used for the prevention and control of this destructive pest. However, the resistance of B. dorsalis to these compounds has become a serious problem. This study tested six sweeteners...

Solenopsis invicta Buren is an important invasive pest that has a negative impact on biodiversity. However, current knowledge regarding the ecological effects of its interaction with honeydew-producing hemipteran insects is inadequate. To partially address this problem, we assessed whether the interaction between the two invasive species S. invicta...

Mutualistic interactions between ants and hemipterans are mediated by the honeydew produced by the hemipterans. Previous works have demonstrated that the invasive mealybug Phenacoccus solenopsis produces abundant honeydew and attracts a large number of workers of the fire ant Solenopsis invicta. Mealybugs exhibit higher fecundity when tended by fir...

Factors promoting the establishment and colonization success of introduced populations in new environments constitute an important issue in biological invasions. In this context, the respective role of pre-adaptation and evolutionary changes during the invasion process is a key question that requires particular attention. The present study compared...

The recent resurgence of bed bugs (Cimex spp.) in many developed countries has drawn increasing attention worldwide. The status of urban bed bug infestations were investigated in Shenzhen and Dongguan, two major cities in southern Guangdong Province of southern China, based on pest control service records from two different companies (one during 20...

The symmetry breaking observed in nature is fascinating. This symmetry breaking is observed in both human crowds and ant colonies. In such cases, when escaping from a closed space with two symmetrically located exits, one exit is used more often than the other. Group size and density have been reported as having no significant impact on symmetry br...

Reproduction is an important life process in insects; however, few studies have attempted to demonstrate the association between reproductive activity and energy metabolism. To address this problem, we focused on the reproductive changes in Bactrocera dorsalis males. We analyzed B. dorsalis male gene expression profiles during mating (DM), 3 h afte...

Mutualism between ants and honeydew-producing hemipterans is a common phenomenon in ecosystems, and interactions between ants and hemipterans have been extensively studied. The invasive solenopsis mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae), and the ghost ant, Tapinoma melanocephalum (F.) (Hymenoptera: Formicidae), are wide...

The olfactory response of fire ants to plant leaves, mealybugs and the honeydew excreted by mealybugs was tested with a Y-tube olfactometer. The foraging activities of fire ants on three plants were also measured. Our results showed that plant leaves and mealybugs alone had no significant attraction to the fire ant workers, while fire ants could be...

Although many reports suggested the economic importance of the red imported fire ant, Solenopsis invicta Buren, few attempts to test the hypothesis that the red imported fire ant-aphid mutualism enhances the occurrence of red imported fire ant on crops, thereby interfering with their flowering and fruiting and affecting their output. To address thi...

In natural as in agricultural ecosystems, interactions between ants and honeydew-producing hemipterans are commonly observed. Mutualisms between invasive ants and hemipterans have been extensively studied in recent years. However, native ant species can equally exploit the honeydew excreted by hemipterans, and establish close relationships with the...

This study evaluated the effect of Fipronil on the survival of fire ant workers with different doses and soil water contents and further examined the persistent effect of the same dose of powder at 10%, 50% and 90% soil water content. The results showed that mortality was positively correlated to the dosage. This result indicated that the survival...

Rapid detection of red imported fire ant (Solenopsis invicta Buren; Hymenoptera: Formicidae) nests is important in assessing the control efforts and for monitoring dispersal of this pest. In this study, spectroscopic techniques were employed to characterize the reflectance spectra of fire ant nest soil and the areas surrounding the nests. The resul...

Plant essential oils restrained the course of foraging behavior of individual worker ants and also influenced worker recruitment and food transport. Worker search times increased significantly among the plant oil treatments. The longest search time was observed for ants treated with essential oils of Capsicum annuum L. (Solanales: Solanaceae) and C...

In this study, the effects of organic silicon (Si) on the toxicity of imidacloprid to a new invasive mealybug, Phenacoccus solenopsis (Hemiptera: Pseudococcidae), infesting Portulaca grandiflora (Caryophyllales: Portulacaceae) plants were evaluated using spotting and dipping methods under laboratory and field conditions to improve management strate...

The involvement of red imported fire ant Solenopsis invicta Buren in the probing behavior of the mealybug Phenacoccus solenopsis Tinsley was investigated. The electrical penetration graph (EPG) technique was applied to compare the different probing behavior of ant-tended and untended adult female mealybugs on hibiscus seedlings. The results showed...