Effect Of Pheromone Research Articles

Helping Rabbits Cope with Veterinary Acts and Vaccine-Related Stress: The Effects of the Rabbit Appeasing Pheromone (RAP).

Rabbits are subjected to challenges that induce stress and require them to continuously adapt. Veterinary procedures represent an important source of stress. In other pets, pheromone use was shown to help patients better cope with these procedures. This study aimed to evaluate whether continuous exposure to the rabbit appeasing pheromone (RAP) could help rabbits cope with the stress induced by routine clinical consultations and vaccinations. Twenty-four 5-week-old rabbits were housed in two identical rooms for 43 days, one in which the rabbits underwent continuous RAP treatment and one with the placebo. The rabbits were vaccinated 8 days afterwards, and their behaviour was evaluated using visual analogic scales (VASs) and videos. The rabbits were also examined seven times, on a weekly basis, using VASs to assess their behaviour. The video analysis showed that the RAP-treated rabbits were less inhibited (p = 0.03) and more in contact with the surgeon (p = 0.039) during vaccinations, while the non-treated rabbits kept their ears in the middle/flattened position (p = 0.003). The RAP-treated rabbits were also less agitated (VAS analysis, p = 0.02). During the consultations, a treatment × day effect was observed in favour of the RAP group for the rabbit state and rabbit reactivity VAS analysis (p < 0.0001). These findings seem to suggest that continuous RAP exposure could be a promising tool for helping rabbits cope with veterinary procedures.

Effects of interspecific sex pheromones on the trapping efficiency of five pest species in an apple orchard

The species Grapholita molesta, Adoxophyes orana, Carposina sasakii, Apolygus lucorum, and Lithocolletis ringoniella are the most important insect pests in apple orchards in China, and their outbreak cycles are partially overlapping. Sex pheromone-based pest monitoring technique is an effective tool for decision-making regarding the use of insecticides. Interactions between interspecific pheromones of pests have not been widely explored, especially of the phylogenetically distant species that have completely different pheromone components. It is unclear whether sex pheromone lures from the five pests could be applied together without compromising their individual effectiveness. To address this knowledge gap, different combinations of commercially available sex pheromone lures were placed in the same trap to evaluate the interactions of interspecific sex pheromones in the field. The annual occurrence and peak of these five pests in the experimental apple orchard were investigated, and the sex pheromone lure of A. lucorum had no impact on the population dynamics and trap catches of A. orana or L. ringoniella. Similarly, the sex pheromone lures of A. orana, G. molesta, C. sasakii, or L. ringoniella did not influence the presence and trap catches of A. lucorum. The sex pheromone lure of A. lucorum can be used separately or in combination with those of four other pests in apple orchards. The study provided a theoretical foundation for effectively managing these five pests by integrating their sex pheromone lures in orchards.

Cardiovascular effects of dog-appeasing pheromone in the hospital environment

Cardiovascular effects of dog-appeasing pheromone in the hospital environment

The effects of queen mandibular pheromone on Nosema (Vairimorpha) ceranae infections in caged honey bees

Honey bees utilize queen mandibular pheromone (QMP) for maintaining social hierarchy and colony development. In controlled cage studies, synthetic QMP is often introduced to mimic natural conditions. However, questions have arisen about the effects of QMP on nosema disease studies. This short report identifies significant early-stage suppression effects of QMP on Nosema (Vairimorpha) ceranae infections. QMP was found to significantly lower infection rates below the reported infectious dose for 50 % infectivity (ID50) and to slow disease development in a dose-independent manner. These effects diminished at doses exceeding ID100. We recommend that studies investigating treatment effects using caged bees avoid QMP to ensure unambiguous results. Additionally, employing multiple infectious doses with shorter incubation times would be useful for evaluating other treatments that may have subtle effects. Furthermore, our findings support previous field studies suggesting that queen replacement reduces nosema disease at levels similar to treatment with fumagillin.

Eligibility traces in an autonomous soccer robot with obstacle avoidance and navigation policy

As the thematic literature of machine learning suggests, reinforcement learning falls between the two methods of supervised learning and unsupervised learning. In this method, the learning agent receives a reward or punishment from the environment according to its action. Therefore, the learning agent interacts with the environment through trial and error and learns to choose the optimal action to achieve its goal. In the meantime, the eligibility traces are considered as one of the main mechanisms of reinforcement learning in receiving delayed rewards. In the use of conventional reinforcement learning methods, when the learning agent achieves a goal, only the value function of the last state-action pair changes, but all the trace states are affected based on the eligibility traces. In other words, the delayed rewards are distributed throughout the trace. Like the ant pheromone effect, this method can increase learning speed empirically to some extent. A soccer robot on the field encounters moving obstacles such as balls, rival robots, and home robots, and fixed obstacles such as gates and flags, so its environment is in a very dynamic state. Therefore, due to the dynamic environment, it is an important issue for autonomous soccer robots to avoid obstacles and should be considered in real play. The main idea of this study is to determine the appropriate traces for the robot to move towards the ball and ultimately to score with the approach of avoiding obstacles in simulating a real soccer match. The desired results obtained from a game played indicate a high level of online experience and decision-making power in the face of new situations.

Early life exposure to queen mandibular pheromone mediates persistent transcriptional changes in the brain of honey bee foragers.

Behavioural regulation in insect societies remains a fundamental question in sociobiology. In hymenopteran societies, the queen plays a crucial role in regulating group behaviour by affecting individual behaviour and physiology through modulation of worker gene expression. Honey bee (Apis mellifera) queens signal their presence via queen mandibular pheromone (QMP). While QMP has been shown to influence behaviour and gene expression of young workers, we know little about how these changes translate in older workers. The effects of the queen pheromone could have prolonged molecular impacts on workers that depend on an early sensitive period. We demonstrate that removal of QMP impacts long-term gene expression in the brain and antennae in foragers that were treated early in life (1day post emergence), but not when treated later in life. Genes important for division of labour, learning, chemosensory perception and ageing were among those differentially expressed in the antennae and brain tissues, suggesting that QMP influences diverse physiological and behavioural processes in workers. Surprisingly, removal of QMP did not have an impact on foraging behaviour. Overall, our study suggests a sensitive period early in the life of workers, where the presence or absence of a queen has potentially life-long effects on transcriptional activity.

Mate search or predation avoidance? Sex pheromone interrupts death feigning of males in the sweet potato weevil Cylas formicarius

Death feigning is hypothesized to be an anti-predator behavior in which prey is temporarily immobilized in response to external stimuli. While death feigning may be an effective predator-defense strategy, there may be trade-offs in terms of energy and time for finding food and/or mating. The duration of death feigning is regulated by the balance of various selection pressures, and its duration is influenced by many internal and environmental factors. However, little is known about the factors that influence arousal from death-feigning behavior. Sex pheromones are important semiochemicals that affect reproductive success and may influence the duration of death-feigning behavior. In this study, we aimed to investigate the effects of sex pheromones on the death-feigning behavior of the sweet potato weevil (Cylas formicarius) by conducting laboratory experiments. The results showed that males had a significantly shorter death-feigning duration in the presence of sex pheromones because it aroused them from their death-feigning behavior, but females were unaffected. This is the first study to show that sex pheromones alter death-feigning behavior. The results of this study elucidate the factors influencing predator-avoidance behavior and reveal the impact of death-feigning behavior on prey reproduction under predation pressure.

A possible pheromone effect as reflected in food handling by Messor arenarius ants

Abstract This work aimed to explore a pheromone effect during food handling using food choice field experiments with Messor arenarius ants. The results showed that the proportion of times ants touched the two food items placed in the artificial food patch (collection point) with their antennae was significantly higher in their first collection attempt than in subsequent attempts. However, when the soil was replaced after each collection attempt, there were no significant differences in the proportions of cases in which ants touched the two food items with their antennae between the first and subsequent food collection attempts. This difference may indicate that ants deposited a pheromone in their first food collection attempt that faded away when the soil in the patch was replaced after each collection attempt.

Pheromone traps and climate variations influence populations of Sahlbergella singularis (Hemiptera: Miridae) and associated damage of cocoa in Cameroon.

Knowledge of insect pest ecology and biology is important for maximizing crop protection and reducing crop losses. Currently, we lack an efficient control program for the cocoa mirid Sahlbergella singularis Haglund (Hemiptera: Miridae), the principal insect pest of cocoa in West and Central Africa. A 2-yr study was conducted in 11 plantations across Ayos and Konye, two of the largest cocoa growing areas of Cameroon. We evaluated the effects of mirid sex pheromone and climatic variations on mirid population dynamics and their associated cocoa damage. Sex pheromone traps caught 1.5-fold higher mirids in Ayos than in Konye, with more overall counts in 2015 than in 2016. Cocoa pod counts were also significantly higher in 2015 than in 2016 and were negatively correlated with temperature and relative humidity. In both localities, mirid populations and associated cocoa pod damage were suppressed in plantations where sex pheromone traps were used. Damage incidence was positively correlated with mirid counts, confirming that the cocoa pod is the preferential site for mirid feeding and reproduction. As such, damage incidence could be used as proxy for comparative mirid population level due to the mirid's cryptic habit. Of the recorded weather variables, only relative humidity was correlated (negatively) with damage severity. Our data on the relationships between damage caused by mirids and their population dynamics and sex pheromone trap catches suggest that an effective control strategy using mass trapping could be developed for mirid management in cocoa plantations.

No evidence that recruitment pheromone modulates olfactory, visual, or spatial learning in the ant Lasius niger

Pheromones are perhaps the most common form of intraspecific communication in the animal kingdom and used in various contexts. Their modulatory potential on cognitive processes has been demonstrated in both vertebrates and invertebrates. Particularly interesting in this regard are social insects, due to their extensive use of pheromones to organise collective behaviour. Recruitment pheromones might be expected to encourage learning, but could also hinder learning due to a blocking effect, whereby the pheromone already partially predicts the reward, hindering further cues being associated with the reward. Here, we use free-running learning assays using realistic pheromone strength to test for a modulation effect on learning in the black garden ant Lasius niger. We found no evidence that learning in three modalities (olfactory, visual, and spatial) is affected by the presence of a realistic pheromone trail. Interestingly, this is in contrast to findings in honeybees. The fact that associative learning does not seem to be influenced by recruitment pheromone in L. niger and reportedly the Argentine ant, while it is in honeybees, the possibly best-studied social insect species, is noteworthy. We speculate that a species-specific importance of social information use could drive modulatory effects of pheromones on a wide range of cognitive processes.Significance statementPheromones have been shown to modulate associative learning in a variety of animals. Among social insects, attractive pheromone has been found to enhance associative olfactory learning in honeybees but not in ants. In ants, recruitment pheromone predicts a food source; therefore, it might hinder learning of a new cue for a food reward. We use a free-running learning assay to test for an effect of trail pheromone on associative learning in three different modalities—olfactory, spatial, visual—in Lasius niger, but find no evidence of any effect. Our learning assay demonstrated fast olfactory learning, moderate spatial learning, and no visual learning after only one training visit. Based on our findings, and findings in two other ant species, we speculate that the ecological foraging conditions of mass-recruiting ants, i.e. following a trail, have not favoured a modulation potential of recruitment pheromone opposed to attractive pheromone in honeybees.

Effect of Pig Synthetic Pheromones and Positive Handling of Pregnant Sows on the Productivity of Nursery Pigs.

Weaning is one of the most important stress events in the life of pigs, increasing the risk for health problems and reduced performance. The release of pheromones in pig stables can be considered an environmental enrichment and alleviate the negative effects of weaning stress in nursery pigs. The present study investigated the effect of synthetic pheromones on the performance of nursery pigs. The effect of positive handling of sows in the farrowing house on the performance of the offspring in the nursery was also investigated. The study was performed in a commercial pig farm and included 24 batches of weaned piglets (216 piglets per batch). Half of the batches originated from sows exposed to positive handling. This implied that music was played from 6.00 a.m. to 6.00 p.m. from the moment the sows entered the farrowing house until weaning and that they were subjected to backscratching from the day they entered the farrowing unit the day of farrowing. During the nursery period, half of the batches were treated, and half served as controls. Piglets of treated groups were exposed to a synthetic analog of the maternal pig appeasing pheromone (PAP) (SecurePig®, Signs, Avignon, France). The product consisted of a gel block from which the pheromones were slowly released into the room. Different performance parameters were measured during the nursery period. Neither the sow treatment nor the treatment with pheromones significantly influenced the performance of the piglets during the nursery period (p > 0.05). The median values (95% confidence interval) of average daily gain, namely 318 (282-338) vs. 305 (272-322) g/day, feed conversion ratio, namely 1.64 (1.51-1.71) vs. 1.70 (1.57-1.75), and number of antimicrobial treatment days, namely 16.9 (9.6-25.0) vs. 17.3 (9.5-25.0) days, were numerically better in the nursery pigs exposed to the pheromones compared to the control groups. Mortality however was numerically higher in the treated groups, namely 4.4 (2.8-6.8) vs. 3.2 (0.9-4.2)%. Under the conditions of the present production system, pigs exposed to the pheromone treatment during the nursery did not show a significant performance increase.

Aggregation pheromone interrupts death feigning in the red flour beetle Tribolium castaneum

AbstractDeath feigning is a behavior in which a prey is rendered motionless due to stimulation or threat by a predator. This anti-predator defense mechanism has been observed across a wide range of animal taxa and is considered adaptive. However, long durations of death feigning can decrease opportunities for feeding and reproduction, and therefore is a fitness cost as compared to environments without predators. Because death feigning is thought to be affected by the balance between survival and other fitness costs, selection pressure may drive individuals who are capable of plastic changes in the intensity of death feigning. Pheromones, which are important semiochemicals that affect foraging and reproductive success, may be one of the factors influencing the intensity of death-feigning behavior. In this study, we investigated the effect of an aggregation pheromone on the death-feigning behavior of the red flour beetle Tribolium castaneum. We found that beetles exposed to the pheromone showed a significantly shorter duration of death feigning than beetles that were not exposed to the pheromone. Therefore, our results suggest that an aggregation pheromone can plasticly alter the death-feigning behavior in T. castaneum.

Evaluation of the Effectiveness of Different Trap Types and Pheromones against Halyomorpha halys (Hemiptera: Pentatomidae)

Brown Marmorated Stink bug (BMSB) (Halyomorpha halys, Hemiptera: Pentatomidae) was first detected in Türkiye in 2017 and is an important invasive insect species worldwide. About 300 hosts have been identified for this pest until recently. Among the hosts of the pest in the Black Sea region, mainly hazelnuts, fruits and vegetables are included. This study was carried out to evaluate the effectiveness of different traps in 2020 and 2021 in a mandarin garden in the Kemalpaşa district of Artvin, one of the places where the pest was first transmitted to Türkiye. Small Funnel Trap (SFT), McPhail Funnel Trap (MPT), Multi-Funnel Trap (MFT), and Big Funnel Trap (BFT) and two different pheromones SMC and TRC were tested against H. halys. Each trap was tested with two different pheromones, and the trapping performances of different trap types were followed from the beginning of July to the end of October. The adults were counted every week in the traps. In the traps, it was determined that the most insect-attractive pheromone and trap type combination was TRC+BFT and that the least effective insect trapping type was the SMC+MPT combination. In general, it was determined that TRC, which is the most effective pheromone, also works effectively with BFT and MPT. It was determined that SMC pheromone formed a more effective combination with SFT. In addition, it is predicted that larger-scale designs of MPT will be more effective together with TRC, and SFT with SMC. In this study, it was determined that the performances of different types of traps and pheromones that can be used in the control and monitoring of BMSB vary up to 29 times, and the importance of the combination of pheromone and trap was revealed.

Integrated effect of insecticide and sex pheromone on the tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae)

The tomato leafminer, Tuta absoluta (Meyrick), is currently a major threat to tomato globally. Growers in Ethiopia rely on insecticides to control the pest, which is not sustainable because of the insect's ability to develop resistance fast. The rational use of pesticides is useful to delay pesticide resistance. The integrated effect of sex pheromone and insecticide in the population of the tomato leafminer and its damage on tomato was investigated for two seasons between 2020 and 2021 at Melkassa center of the Ethiopian Institute of Agricultural Research (EIAR). Treatments consisted of trapping using sex pheromone alone, insecticide use alone and a combination of trapping using sex pheromone and insecticide (integrated treatment) along with the untreated control. Four fields, each with three replicates of plots for each treatment were used by keeping each field wide apart to minimize the movement of adult population of the insect. Treatment effects were assessed by counting the immature stages of the insect and damage both on the leaves and tomato fruits. Treatments differed significantly for mining larvae but not for the number of eggs. Leaf damage was significantly higher in the untreated control than in the rest of the treatments. In both years, similar trends of results for the percentage of damaged fruits were observed, which was lowest in the integrated treatment followed by insecticide alone, pheromone trap alone and untreated control. Results from this study suggest the need to integrate pheromone traps with insecticides to achieve better protection from Tuta absoluta damage on tomato.

Parallel Olfactory Systems Synergistically Activate the Posteroventral Part of the Medial Amygdala Upon Alarm Pheromone Detection in Rats

In rats, a mixture of hexanal and 4-methylpentanal is a main component of the alarm pheromone. When detected by the main olfactory system (MOS) and the vomeronasal system, respectively, they activate the anterior part of the bed nucleus of the stria terminalis (BNSTa). Therefore, the information from the two olfactory systems is expected to be integrated before being transmitted to the BNSTa. To specify the integration site, we examined Fos expression in 16 brain regions in response to water (n = 10), hexanal (n = 9), 4-methylpentanal (n = 9), the mixture (n = 9), or the alarm pheromone (n = 9) in male rats. The posteroventral part of the medial amygdala showed increased Fos expression to hexanal and 4-methylpentanal. The expression was further increased by the mixture. Therefore, this region is suggested as the integration site. In addition, the BNSTa, paraventricular nucleus of the hypothalamus, and anteroventral, anterodorsal, and posterodorsal parts of the medial amygdala were suggested to be located downstream of the integrated site because only the mixture increased Fos expression. We suggest that the posterolateral part of the cortical amygdala is upstream of the integration site in the MOS because all stimuli increased Fos expression. The posterior part of the bed nucleus of the stria terminalis and posteromedial part of the cortical amygdala were suggested as being located upstream in the vomeronasal system because 4-methylpentanal and the mixture increased Fos expression. These results provide information about the neural pathway underlying the alarm pheromone effects.

Determination of Hourly Distribution of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) Using Sex Pheromone and Ultraviolet Light Traps in Protected Tomato Crops

Tuta absoluta (Meyrick), a leafminer that damages tomato leaves, terminal buds, flowers, and fruits, is a destructive tomato pest and is responsible for 80–100% of tomato yield losses globally. Different insect species have different courtship responses and phototropic flight rhythms. Improving the trapping effects of the sex pheromone and light traps is important for constructing an IPM system for T. absoluta. The present study explored the hourly distribution of T. absoluta adults caught by the sex pheromone (on the ground) and UV light (380 nm) traps in greenhouses over 24 h. The responses of males to sex pheromone (false female) lures were detected at dawn and early morning. The responses lasted for 3 h, from 05:30 (1 h before sunrise) to 08:30 (2 h after sunrise), and 95.8% of the males were caught during this period. The peak of the male responses to the sex pheromone was detected at 07:30 (from 06:30 to 07:30, 1 h after sunrise), and 80.8% of the males were caught during this period. The flight of male (proportion of 54.3%) and female (45.7%) adults toward the UV light traps occurred from 19:30 (time of sunset) to 06:30 (time of sunrise), lasted for 11 h, and exhibited a scotophase rhythm; 97.4% of the adults were caught during this period. The peak of adults flying toward the UV light traps occurred at 21:30 (from 20:30 to 21:30, 2 h after sunset). The rhythms of males’ responses to the sex pheromone and of the adults’ flight toward the UV lights can help to reveal the mechanisms of chemotactic and phototactic responses and may play a significant role in constructing an IPM system for this pest.

Pheromone effect of estradiol regulates the conjugative transfer of pCF10 carrying antibiotic resistance genes

Horizontal gene transfer (HGT) mediated by conjugative plasmids greatly contributes to bacteria evolution and the transmission of antibiotic resistance genes (ARGs). In addition to the selective pressure imposed by extensive antibiotic use, environmental chemical pollutants facilitate the dissemination of antibiotic resistance, consequently posing a serious threat to the ecological environment. Presently, the majority of studies focus on the effects of environmental compounds on R plasmid-mediated conjugation transfer, and pheromone-inducible conjugation has largely been neglected. In this study, we explored the pheromone effect and potential molecular mechanisms of estradiol in promoting the conjugative transfer of pCF10 plasmid in Enterococcus faecalis. Environmentally relevant concentrations of estradiol significantly increased the conjugative transfer of pCF10 with a maximum frequency of 3.2 × 10-2, up to 3.5-fold change compared to that of control. Exposure to estradiol induced the activation of pheromone signaling cascade by increasing the expression of ccfA. Furthermore, estradiol might directly bind to the pheromone receptor PrgZ and promote pCF10 induction and finally enhance the conjugative transfer of pCF10. These findings cast valuable insights on the roles of estradiol and its homolog in increasing antibiotic resistance and the potential ecological risk.

Ants prefer the option they are trained to first.

The temporal order in which experiences occur can have a profound influence on their salience. Humans and other vertebrates usually memorise the first and last items of a list most readily. Studies on serial position learning in insects showed preference for last encountered items, mainly in bees. In bees, pheromone presence can also influence motivation, and thus learning. However, neither serial position learning not the effect of recruitment pheromones on learning have been well investigated in ants. We trained Lasius niger foragers to make multiple visits to sucrose on a runway which alternated between lemon or rosemary odour, and the presence or absence of trail pheromone, ant then tested for preference between the odours on a Y-maze, in order to investigate the effect of pheromone presence on learning. Pheromone presence did not affect ant choice. However, unexpectedly, the ants strongly preferred the first odour encountered. This was explored by the addition of a familiarisation visit without pheromone or odour. The familiarisation visit disabled or reversed this preference for the first odour encountered, with ants now mostly taking their 'default' preference by choosing the left side of the maze. Our study found no effect of trail pheromone on learning, but a strong yet fragile preference for the first odour experienced. These different preferences could lead to spatial segregation of foraging activity depending on prior experience and might facilitate efficient resource exploitation by colonies.

Insect Pest Pheromone Lures May Enhance the Activity of Insectivorous Bats in Mediterranean Vineyards and Apple Orchards

Insectivorous bats may play a significant role in regulating populations of agricultural pests. Currently, few methods are available to enhance the activity of bats in agroecosystems. We asked whether synthetic sex pheromones, used in integrated pest management (IPM) to impede the mating success of major moth pests in vineyards and apple orchards, could also enhance the activity and richness of insectivorous bats, their natural enemies. We hypothesized that applying concentrated sex pheromones of pest moths will alter the movement patterns of male moths, indirectly affecting bat richness and activity. We compared the effect of sex pheromones on bats under two different agricultural management systems: conventional farming and IPM. We used synthetic sex pheromones of Lobesia botrana or Cydia pomonella; both are among the most destructive moth pests in vineyards and apple orchards, respectively. Using passive acoustic monitoring, we compared species richness and bat activity in plots without and with additional pheromones. In both IPM vineyards and IPM apple orchards, total bat activity and species richness significantly increased after applying the pheromone treatment, with a positive correlation between total bat activity and the numbers of moth pests in the vineyards. In conventional vineyards, bat species richness increased significantly, but not total bat activity. IPM vineyards had significantly higher species richness than conventional vineyards, both before and after the pheromone treatment. Our study shows that moth pheromone lures, commonly used as a pest control method, may also attract insectivorous bats, which in turn may further suppress the pests. These findings highlight the potential of insectivorous bats as pest control agents and call for further research directed at integrating them in IPM practices.

Bisphenols Promote the Pheromone-Responsive Plasmid-Mediated Conjugative Transfer of Antibiotic Resistance Genes in Enterococcus faecalis.

The enrichment and spread of antibiotic resistance genes (ARGs) induced by environmental chemical pollution further exacerbated the threat to human health and ecological safety. Several compounds are known to induce R plasmid-mediated conjugation through inducing reactive oxygen species (ROS), increasing cell membrane permeability, enhancing regulatory genes expression, and so forth. Up to now, there has been no substantial breakthrough in the studies of models and related mechanisms. Here, we established a new conjugation model using pheromone-responsive plasmid pCF10 and confirmed that five kinds of bisphenols (BPs) at environmentally relevant concentrations could significantly promote the conjugation of ARGs mediated by plasmid pCF10 in E. faecalis by up to 4.5-fold compared with untreated cells. Using qPCR, gene knockout and UHPLC, we explored the mechanisms behind this phenomenon using bisphenol A (BPA) as a model of BPs and demonstrated that BPA could upregulate the expression of pheromone, promote bacterial aggregation, and even directly activate conjugation as a pheromone instead of producing ROS and enhancing cell membrane permeability. Interestingly, the result of mathematical analysis showed that the pheromone effect of most BPs is more potent than that of synthetic pheromone cCF10. These findings provide new insight into the environmental behavior and biological effect of BPs and provided new method and theory to study on enrichment and spread of ARGs induced by environmental chemical pollution.