RESUMEN

BACKGROUND: The whitefly Bemisia tabaci is one of the world's foremost agricultural pests. Recently, we found that a wild relative of tobacco (Nicotiana benthamiana) demonstrates remarkable attractiveness and nearly 100% lethality towards whiteflies. Therefore, it can act as a dead-end trap crop for whitefly control in the field. However, the underlying mechanism of the significant attractiveness of N. benthamiana towards whiteflies is unclear. RESULTS: Binary-choice assays and olfactory experiments showed that compared to common tobacco (N. tabacum), the volatile of N. benthamiana has a greater attraction to whiteflies. Then we analyzed and compared volatiles from these two Nicotiana species by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). We identified 16 chemical compounds that are more abundant in N. benthamiana than in N. tabacum. Seven compounds were further tested with olfactometer assays and we found that, among them, undecane strongly attracted whiteflies. Further experiments revealed that even 0.005 µg mL-1 undecane is attractive to whiteflies. We also silenced the genes that may influence the biosynthesis of undecane and found the production of undecane decreased after silencing NbCER3, and that N. benthamiana plants with less undecane lost their attraction to whiteflies. In addition, we found that applying 0.005 µg mL-1 undecane on yellow sticky traps can increase the number of stuck insects on the traps by ≈40%. CONCLUSION: Undecane from the volatile of N. benthamiana is a critical chemical signal that attracts whiteflies and NbCER3 involved in the biosynthesis of undecane. Undecane may be used to improve the efficiency of yellow sticky traps for whitefly control. © 2024 Society of Chemical Industry.

RESUMEN

Large mammals respond to human hunting via proactive and reactive responses, which can induce subsequent nonconsumptive effects (NCEs). Thus, there is evidence that large mammals exhibit considerable behavioral plasticity in response to human hunting risk. Currently, however, it is unclear which cues of human hunting large mammals may be responding to. We conducted a literature review to quantify the large mammal behavioral responses induced by the cues of human hunting. We detected 106 studies published between 1978 and 2022 of which 34 (32%) included at least one measure of cue, typically visual (n = 26 of 106, 25%) or auditory (n = 11 of 106, 10%). Space use (n = 37 of 106, 35%) and flight (n = 31 of 106, 29%) were the most common behavioral responses studied. Among the 34 studies that assessed at least one cue, six (18%) measured large mammal behavioral responses in relation to proxies of human hunting (e.g. hunting site or season). Only 14% (n = 15 of 106) of the studies quantified an NCE associated with an animal's response to human hunting. Moreover, the association between cues measured and antipredator behaviors is unclear due to a consistent lack of controls. Thus, while human hunting can shape animal populations via consumptive effects, the cues triggering these responses are poorly understood. There hence remains a need to link cues, responses, NCEs, and the dynamics of large mammal populations. Human activities can then be adjusted accordingly to prevent both overexploitation and unintended NCEs in animal populations.

RESUMEN

Thimerosal (THI) has become a significant source of organic mercury pollutants in aquatic ecosystems, but there is limited information regarding its adverse effects on fish. In this study, zebrafish embryos were exposed to THI at 0 (control), 5.0, and 50 ng/L from 0-5 days post fertilization (dpf), and variations in their survival, development, behavior, free amino acid contents, and the biochemical responses involved in monoaminergic systems were examined. Although THI exposure did not significantly affect the survival, heart rate, or hatching time of zebrafish embryos, it substantially increased swimming velocity (136-154 % of the control) and reduced exploratory behavior (141-142 % of the control) in zebrafish larvae at 5 dpf. Exposure also significantly altered the amino acid contents (51-209 % of the control) and monoamine levels (70-154 % of the control) in zebrafish larvae, some of which displayed significant correlations with behavioral traits. THI significantly elevated dopamine receptor gene expression and monoamine oxidase activity in zebrafish larvae. Adding extra phenylalanine or tryptophan to the E3 medium facilitates the recovery of zebrafish larvae from the abnormal behaviors induced by THI. These findings reveal for the first time that THI exposure at the level of ng/L is sufficient to induce neurobehavioral toxic effects in the early life stages of zebrafish, and disrupting amino acid homeostasis is a critical underlying mechanism. This study provides valuable insights into the toxicity of THI to fish and highlights the importance of assessing its potential risks to aquatic ecosystems.

Asunto(s)

RESUMEN

Aphidius gifuensis is the dominant parasitic natural enemy of aphids. Elucidating the molecular mechanism of host recognition of A. gifuensis would improve its biological control effect. Chemosensory proteins (CSPs) play a crucial role in insect olfactory systems and are mainly involved in host localization. In this study, a total of nine CSPs of A. gifuensis with complete open reading frames were identified based on antennal transcriptome data. Phylogenetic analysis revealed that AgifCSPs were mainly clustered into three subgroups (AgifCSP1/2/7/8, AgifCSP3/9, and AgifCSP4/5/6). AgifCSP2/5 showed high expression in the antennae of both sexes. Moreover, AgifCSP5 was found to be specifically expressed in the antennae. In addition, fluorescent binding assays revealed that AifCSP5 had greater affinities for 7 of 32 volatile odor molecules from various sources. Molecular docking and site-directed mutagenesis results revealed that the residue at which AgifCSP5 binds to these seven plant volatiles is Tyr75. Behavior tests further confirmed that trans-2-nonenal, one of the seven active volatiles in the ligand binding test, significantly attracted female adults at a relatively low concentration of 10 mg/mL. In conclusion, AgifCSP5 may be involved in locating aphid-infested crops from long distances by detecting and binding trans-2-nonenal. These findings provide a theoretical foundation for further understanding the olfactory recognition mechanisms and indirect aphid localization behavior of A. gifuensis from long distances by first identifying the host plant of aphids.

Asunto(s)

RESUMEN

Controlled nigrostriatal dopamine release supports effective limb use during locomotion coordination that becomes compromised after this pathway deteriorates in Parkinson's Disease (PD). How dopamine release relates to active ongoing behavior control remains unknown. Restoring proper release strategy appears important to successful PD treatment with transplanted dopamine-producing stem cells. This is suggested by apparently distinct behavioral support from tonic or phasic release and corresponding requirements of requisite afferent control exhibited by intact nigrostriatal neurons. Our laboratory previously demonstrated that transplanted dopaminergic cells can elicit skilled movement recovery known to depend on phasic dopamine release. However, efforts to measure this movement-related dopamine release yielded seemingly paradoxical, incongruent results. In response, here we explored whether those previous observations derived from rapid reuptake transport into either transplanted cells or residual, lesion-surviving terminals. We confirmed this using minimal reuptake blockade during intrastriatal microdialysis. After unilateral dopamine depletion, rats received transplants and were subjected to our swimming protocol. Among dopamine-depleted and transplanted rats, treatment supported restoration of limb movement symmetry. Interestingly, subsequent reuptake-restricted microdialysis confirmed distinct swimming-induced dopamine increases clearly occurred among these lesioned/transplanted subjects. Thus, phasic firing control appears to contribute to transplant-derived recovery in Parkinsonian animals.

Asunto(s)

RESUMEN

Epidermal club cells (ECCs) are present in many species of teleost fish. In an attempt to justify their presence in the epidermis of fish, they have been associated with numerous functions. One proposed function is communication with conspecifics during a predation event, as these cells may passively release substances upon rupture, which may occur during predation. We identified the presence and distribution of ECCs in the body skin of adult cardinal tetra, Paracheirodon axelrodi (Schultz, 1956) and analyzed the animal's behavioral response to conspecific skin extract in a laboratory setting. The identification and distribution of ECCs in the epidermis of the animals were confirmed by conventional histology and immunohistochemistry. Our results demonstrated that: ECCs are present in the skin of the entire body; a high density is observed in the dorsal side from head to tail, in the insertion of the fins and in the epidermis covering them; and ventral distribution is less extensive and more dispersed than dorsal distribution. Treatment of P. axelrodi specimens with skin preparations of conspecifics resulted in behavioral changes in the animals: they showed erratic swimming movements, they showed avoidance of the area of stimulus application and they decreased the time spent moving. Overall, these results allow us to conclude that P. axelrodi possesses ECCs throughout the body, with a greater presence in areas of high exposure to predation events (dorsal area and fins). Animals exposed to conspecific skin extract showed a significant increase in behaviors described as anti-predatory in other species. This supports the hypothesis that ECCs may be the origin of chemical alarm cues that are passively released when skin damage occurs, alerting the rest of the group to the risk of predation.

Asunto(s)

RESUMEN

Previous research has focused on examining embarrassment in sensitive product purchase situations. Although embarrassment is a widespread emotion in consumption situations, few studies have explored its impact on service encounters, especially in the service failure context. This study examines how customers react to different service failures that cause embarrassment and explores whether self-serving bias exists when customers perceive higher embarrassment in service failure. This study uses a 2 (source of failure) × 2 (level of embarrassment) scenario experimental method to examine the effect of two sources of failure on consumer locus attributions, negative emotions, and negative behaviors, considering the moderating effects of the level of embarrassment. Data were collected from 218 student subjects in Taiwan. The results show that embarrassment is important in service failure contexts. Specifically, when consumers perceive higher embarrassment, they attribute more responsibility to the service provider. These attributions, in turn, influence customers' emotions and behavioral responses. These findings have several important theoretical and practical implications in terms of embarrassing service failures.

RESUMEN

BACKGROUND: Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae), a dominant predatory natural enemy species in cotton-planting, is a key biological control agent for aphids in China. Our previous study showed that herbivore-induced plant volatiles (HIPVs) from Glycyrrhiza uralensis (Fisch.) (Fabales: Fabaceae) and Alhagi sparsifolia (Desv.) (Fabales: Fabaceae) plants infested with Aphis atrata (Zhang) (Homoptera: Aphididae), were important semiochemicals for Hippodamia variegata to locate aphids. However, little was known about the varieties and function of active volatiles from HIPVs of the two plant species. RESULTS: In this study, results from gas chromatography-electroantennography detection (GC-EAD) demonstrated that seven HIPVs (butyl acrylate, α-pinene, butyl isobutyrate, ß-pinene, butyl butyrate, 1,3-diethylbenzene and 1,4-diethylbenzene) identified from the two damaged plant species elicited antennal responses from Hippodamia variegata. Also, results from gas chromatograph-mass spectrometry (GC-MS) analysis showed that the concentrations of the seven active volatiles were significantly higher than those from corresponding healthy plants. Hippodamia variegata exhibited varying degrees of response to each active volatile in electroantennography (EAG) trials, however, only α-pinene, butyl isobutyrate, ß-pinene and butyl butyrate significantly attracted Hippodamia variegata in behavioral trials conducted in the laboratory. They also had a better trapping effect on Hippodamia variegata in cotton fields. CONCLUSION: Four active compounds (α-pinene, butyl isobutyrate, ß-pinene and butyl butyrate) identified from two damaged plant species were considered the most effective HIPVs that attract Hippodamia variegata. These findings provide possibilities for the development of Hippodamia variegata attractants. They also provide a theoretical basis for the biological prevention and control of aphids using Hippodamia variegata. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Asunto(s)

RESUMEN

Sexual victimization is prevalent among college women with a history of childhood abuse (CA), which some research suggests is linked to impaired risk perception for sexual victimization or difficulties identifying and responding to unwanted sexual advances. Alexithymia is one construct yet to be examined in the association between CA and risk perception for sexual victimization. The purpose of this study was to elucidate the associations between CA, alexithymia, and risk perception for sexual victimization in a sample of college women with a history of CA. Participants included 294 undergraduate women with a history of childhood emotional, physical, and/or sexual abuse (Mage = 20.6, 80.6% White). An a priori path analysis was conducted to examine whether alexithymia indirectly explains the association between CA and risk perception for sexual victimization (i.e., comprising two related constructs, including threat detection and behavioral response to threat). Supplementary analyses were conducted post hoc to examine potential differences across CA subtypes (emotional, physical, and sexual). Alexithymia indirectly explained the relationship between CA and threat detection, and behavioral response to threat. However, indirect effects were negative, suggesting that undergraduate women with more severe CA and alexithymia identify sexual assault threat cues and intentions to "leave" a hypothetical sexual assault scenario sooner rather than later. The same pattern of results was observed for emotional and physical (but not sexual) CA when examining their indirect effects on threat detection, and for emotional CA when examining behavioral response to threat. Findings contribute to the literature on sexual victimization by clarifying the role of alexithymia in risk perception for sexual victimization. Results also highlight the potential utility of increasing emotional literacy among college women with a history of CA (and especially emotional abuse) to facilitate adaptive responding to unwanted sexual advances.

Asunto(s)

RESUMEN

Circadian rhythm is one of the biorhythms formed by organisms in the process of evolution to adapt to the rotation of the earth,which is manifested as a cyclical biorhythm of about 24 hours produced by the body under the control of the internal biological clock,coordinating sleep/wakefulness,body temperature regulation,endocrine time and other activities.Long-term circadian rhythm disorders can cause increased risk of metabolic disorders,gastrointestinal diseases,neurodegenerative diseasesand other illnesses.As a typical model animal,the aquatic organism zebrafish(Danio rerio)has been widely used in experimental studies of circadian rhythm.This paper introduces in detailthe operating mechanism of zebrafish circadian clock,the influencing factors of the input system,the genes and pathways of the circadian clock,and the physiological output,summarizes the application and advantages in circadian rhythm research,finally looks forward to future research and development,in order to provide theoretical support for circadian rhythm regulation mechanism research,related drug development and disease treatment strategies.

RESUMEN

The insect olfactory recognition system plays a crucial role in the feeding and reproductive behaviors of insects. The odorant receptor co-receptor (Orco), as an obligatory chaperone, is critical for odorant recognition by way of forming heteromeric complexes with conventional odorant receptors (ORs). To investigate the biological functions of Orco in perceiving host plant volatiles and sex pheromone, the Orco gene was identified from the chive maggot Bradysia odoriphaga transcriptome data. Multiple sequence alignment reveals that BodoOrco exhibits an extremely high sequence identity with Orcos from other dipteran insects. The expression of BodoOrco is significantly higher in adults than in larvae and pupae, and the BodoOrco gene is primarily expressed in the antennae of both sexes. Furthermore, the Y-tube assay indicated that knockdown of BodoOrco leads to significant reductions in B. odoriphaga adults' response to all tested host plant volatiles. The dsOrco-treated unmated male adults show less attraction to unmated females and responded slowly compared with dsGFP control group. These results indicated that BodoOrco is involved in recognition of sex pheromone and host plant volatiles in B. odoriphaga and has the potential to be used as a target for the design of novel active compounds for developing ecofriendly pest control strategies.

Asunto(s)

RESUMEN

Olfaction is crucial for Empoasca onukii Matsuda to recognize odors from the host and nonhost plants, and it has been proposed that odorant binding proteins are directly required for odorant discrimination and represent potential targets of interest for pest control. Here, we cloned EonuOBP43 and expressed the recombinant EonuOBP43 protein. Furthermore, competitive fluorescence binding assays with 19 ligands indicated that terpenoids and alkanes showed a relatively higher than for other classes of chemicals. Additionally, ligand docking and site-directed mutagenesis results revealed that seven hydrophobic residues, including Val-86, Met-89, Phe-90, Ile-104, Ile-105, Leu-130, and Val-134, played a key role in the binding of EonuOBP43 to plant volatiles. In olfactometer tests, E. onukii were significantly attracted to α-farnesene and repelled to ß-caryophyllene, and dsOBP43 treated adult lost response to α-farnesene and ß-caryophyllene. In summary, our results demonstrated that EonuOBP43 may function as a carrier in the process of sensing plant compounds of E. onukii.

Asunto(s)

RESUMEN

Intergenerational integration has given rise to a novel aging paradigm known as all-age communities, which is garnering international attention. In China, the aging population and the implementation of the three-child policy have resulted in increased demand for retirement and childcare services among residents in older neighborhoods. Consequently, there is a pressing need to retrofit these older neighborhoods to accommodate all-age living arrangements given the high demand they generate. Therefore, this study undertakes research interviews with residents and constructs an exploratory theoretical model rooted in established theory. To assess the significance of our model, we employ Smart PLS 3.0 based on 297 empirical data points. Our findings indicate that anxiety has a significant negative effect on payment behavior; objective perception, willingness to pay, and government assistance exert significant positive effects on payment behavior. By comprehensively analyzing the mechanisms underlying residents' payment behavior, this study provides valuable insights for the government for promoting the aging process within communities and formulating effective transformation policies.

RESUMEN

Objective: The human immunodeficiency virus has become one of the world's most serious health and development challenges. Human immunodeficiency virus prevention has not received sufficient attention, and the prevalence of human behavioral virus infections among Ethiopian high school and preparatory students has also increased. The aim of this study was to assess behavioral responses to condom use messages to prevent human immune virus/acquired immune deficiency syndrome among Bahir Dar city high school and preparatory students using the extended parallel process model, Bahir Dar, Ethiopia, 2022. Methodology: This institution-based cross-sectional study was conducted from 15 November to 15 December 2022, in Bahir Dar city. The data were collected from 601 participants. A multi-stage sampling technique was used to select the study participants. Data were entered into Epi-Info version 7.2.5 and exported to SPSS version 26 for analysis. Descriptive statistics, percentages, and frequencies were calculated. Bivariable logistic regression was performed to identify variables candidates for multivariable logistic regression at p-values less than 0.25, and multivariable logistic regression was performed to identify factors associated with the outcome variable at p-values < 0.05. A 95% confidence interval and odds ratio were used for the interpretation of the association. Result: The response rate of the respondents was 94.9%. The behavioral response for condom use messages was affected by grade level adjusted odds ratio, 0.473, 95% CI (0.252-0.886), knowledge adjusted odds ratio, 2.627, 95% CI (1.788-3.859), attitude adjusted odds ratio, 3.19, 95% CI (2.145-4.744), efficacy adjusted odds ratio, 3.286, 95% CI (2.03-5.339), and threat adjusted odds ratio, 0.249, 95% CI (0.167-0.369). The behavioral response for condom use messages was associated with danger control. Conclusion: The danger control response is 60.9%. Grade level, knowledge, attitude, and perceived and threat efficacies were independent predictors of danger control. Therefore, messages must aim to enhance threat component perception with appropriate efficacy to control danger and developed using scientific health communication strategies to promote behavioral change.

RESUMEN

ABSTRACTProtein deficiency, characterized by an inadequate intake of protein in the diet that fails to meet the body's physiological requirements across various stages, can lead to detrimental outcomes. This is of interest due to the persistent low protein content in staple foods and suboptimal dietary patterns. The study sought to assess the intergenerational repercussions of dietary protein deficiency on specific neurochemicals and the cytoarchitecture of the brain within the F1 and F2 generations of rats. The rats were categorized into four groups based on the protein content percentage in their diets: 21% protein diet (21%PD), 10% protein diet (10%PD), 5% protein diet (5%PD), and control diet. Neurobehavior was assessed, while brain serotonin and dopamine levels were measured using HPLC. BDNF and GDNF expression in the hippocampal and prefrontal (PFC) sections, Immunohistochemical investigations of the morphological impact on the hippocampus and PFC, were also analyzed. The protein-deficient groups displayed anxiety, loss of striatal serotonin and increased dopamine levels, degenerated pyramidal cells in the hippocampus, and a prominent reduction in cellular density in the PFC. BDNF and GDNF levels in the PFC were reduced in the 5%PD group. GFAP astrocyte expression was observed to be increased in the prefrontal cortex (PFC) and hippocampal sections, indicating heightened reactivity. The density of hypertrophied cells across generations further suggests the presence of neuroinflammation. Changes in brain structure, neurotransmitter levels, and neurotrophic factor levels may indicate intergenerational alterations in critical regions, potentially serving as indicators of the brain's adaptive response to address protein deficiency across successive generations.

RESUMEN

This research investigates parent-adolescent conflicts from the viewpoint of Vietnamese adolescents. Employing a mixed-method approach, the study conducted in-depth interviews and a questionnaire survey with 706 high-school students. The findings highlight that conflicts between Vietnamese parents and adolescents commonly arise regarding internet usage for entertainment and academic purposes. Furthermore, adolescents reported having more conflicts with their mothers than with their fathers. Although instances of parental aggression were identified, most adolescents perceived their parents' conflict resolution as supportive. However, Vietnamese adolescents tended to display passive behavioral responses during conflicts. The research also identified certain emotional responses as warning signs of mental health issues, including suicidal thoughts, among some adolescents. Moreover, a higher frequency of conflicts with parents was significantly associated with increased peer connections. The study emphasizes the importance of professionals, such as school social workers or counselors, prioritizing the understanding of parent-child conflicts' impact on adolescents' emotions and mental health. Additionally, it underscores the significance of examining parenting patterns and parent-child communication within contemporary Vietnamese families.

RESUMEN

Semiochemicals produced by microbes in hemipteran honeydew play an important role in mediating the ant-hemipteran interaction. However, the specific volatile compounds and their origins remain unclear. Here, we found that honeydew produced by Phenacoccus solenopsis exhibited strong attractiveness to fire ant workers, but sterilized honeydew was much less attractive. Four compounds were identified from the honeydew volatiles, including 1-octen-3-ol, limonene, phenylethyl alcohol, and 2,4-ditert-butylphenol. All the identified compounds triggered strong electroantennography response of fire ants and showed repellence at relatively high concentrations while attractiveness at low concentrations to fire ant workers. Furthermore, six bacterial isolates were identified based on 16S rRNA sequencing, namely, Bacillus, Brachybacterium, Kocuria, Microbacterium, Pseudomonas, and Staphylococcus. Fire ants exhibited a strong preference for Brachybacterium, Kocuria, and Microbacterium, suggesting that these bacterial isolates are involved in the attracting effect of honeydew. Both limonene and phenylethyl alcohol were detected from Brachybacterium, while limonene was only detected from Kocuria, and phenylethyl alcohol was exclusively detected from Microbacterium. Reinoculation of these bacteria restored the attractiveness of honeydew to fire ants, and the active compounds, limonene and phenylethyl alcohol, were detectable in bacteria-reinoculated honeydew. Collectively, our results reveal the active compounds in hemipteran honeydew and their association with honeydew bacteria. The findings will contribute to the development of novel attractants for efficient monitoring of fire ants.

Asunto(s)

RESUMEN

Evaluating the toxicity of Palm Oil Mill Effluent (POME) is critical as part of the effort to develop waste management regulations for the palm oil industry. In this study, we investigated the acute toxicity of POME on growth performance, behavioral response, and histopathology of gill and liver tissues of zebrafish (Danio rerio). In total, 550 adult male zebrafish were used for the toxicity experiment including range finding test, acute toxicity test, growth performance and behaviour test. Static non-renewal acute toxicity bioassays were conducted by exposing fish to POME (1.584-9.968 mL/L) for 96 h. Growth performance, behavior response, and histopathological lesions in untreated and POME treated (96-h LC50: 5.156 mL/L) fish were measured at 24, 48, 72 and 96 h. Time-dependent significant decline in body length and body weight of POME-exposed zebrafish was observed. Furthermore, several behavioral changes were recorded, including hyperactivity, loss of balance, excessive mucus secretion, and depigmentation. Decreasing operculum movement and oxygen consumption rate as well as alterations in gill tissues (i.e. hyperplasia, hypertrophy, hemorrhage, and necrosis) of POME-exposed zebrafish were observed, suggesting a dysfunction in respiratory performance. On the other hand, liver tissue alterations (congestion, hemorrhage, hyperplasia, shrinkage of hepatocytes, hydrophilic degeneration, and necrosis) indicated a disruption in detoxification performance. We conclude that exposure to POME at acute concentration caused histopathological lesions both in gill and liver tissue along with changes in fish behaviors which disrupted respiratory and detoxification performance, resulting in mortality and reduced growth of zebrafish. These findings might provide valuable information for guiding POME management and regulation.

Asunto(s)

RESUMEN

Behavioral persistency reflects internal brain states, which are the foundations of multiple brain functions. However, experimental paradigms enabling genetic analyses of behavioral persistency and its associated brain functions have been limited. Here, we report novel persistent behavioral responses caused by electric stimuli in the nematode Caenorhabditis elegans. When the animals on bacterial food are stimulated by alternating current, their movement speed suddenly increases 2- to 3-fold, persisting for more than 1 minute even after a 5-second stimulation. Genetic analyses reveal that voltage-gated channels in the neurons are required for the response, possibly as the sensors, and neuropeptide signaling regulates the duration of the persistent response. Additional behavioral analyses implicate that the animal's response to electric shock is scalable and has a negative valence. These properties, along with persistence, have been recently regarded as essential features of emotion, suggesting that C. elegans response to electric shock may reflect a form of emotion, akin to fear.

Asunto(s)

RESUMEN

Introduction: Bystanders account for the largest proportion of those involve in cyberbullying and play an important role in the development of cyberbullying incidents. Regarding the classification of bystander behavior in cyberbullying, there exist some limitations in the previous research, such as not considering the complexity of the online environment. Therefore, this study constructed a new classification model of bystander behavior in cyberbullying. Methods: By separately utilizing questionnaires and experimental methods, the study collected participants' behavioral intentions and actual behavioral responses to deal with cyberbullying incidents. Results: Based on two qualitative studies, this study summarized a new classification model, which included three first-level factors and six second-level factors. Specifically, the classification model included positive bystander behavior (i.e., pointing at the victim, bully, and others), neutral bystander behavior (i.e., inaction), and negative bystander behavior (i.e., supporting and excessively confronting the bully). Discussion: The classification model has important contributions to the research on bystander behavior in cyberbullying. This model helps researchers to develop more effective intervention approaches on cyberbullying from the perspective of each category of bystander behavior.