OBJECTIVES: To investigate how larval feeding regimens influence development and deltamethrin resistance of Aedes albopictus to provide evidence for standardizing larval feeding protocols in studies of insecticide resistance. METHODS: Aedes albopictus larvae of a laboratory resistant strain were divided into 3 groups (n=500) and reared with high, medium, and low food availability (100, 50, or 25 mg daily for the 1st and 2nd instars, and 500 mg 250, or 125 mg daily for 3rd and 4th instars). The developmental time, pupation rate, adult emergence rate, adult body weight, and wing length were recorded in each group, and deltamethrin resistance of the mosquitoes was assessed using larval bioassays and contact tube tests for adults. RESULTS: Significant developmental differences were observed across the 3 feeding groups. Larval development time decreased as the food availability increased, and both high- and low-food groups showed reduced pupation rates (χ²=16.282, 7.440) and emergence rates (χ²=4.093, 6.977) compared to the medium-food group. Adult body weight and wing length were positively correlated with the amount of larval food intake (P<0.05). In high, medium and low food intake groups, larval LC₅₀ values for deltamethrin were 0.110, 0.072 and 0.064 mg/L, adult KDT50 values were 97.404, 68.964 and 65.005 min, and adult mosquitoe mortality rates at 24 h after deltamethrin exposure were 12%, 16% and 19%, respectively. CONCLUSIONS The feeding amount during larval stage significantly impacts the development and deltamethrin resistance of Aedes albopictus, suggesting the importance of standardization of larval nutrition for ensuring comparability of resistance test data across laboratories.
Animals ; Aedes/physiology* ; Pyrethrins/pharmacology* ; Nitriles/pharmacology* ; Larva/physiology* ; Insecticide Resistance ; Insecticides/pharmacology* ; Feeding Behavior

Circadian rhythms are core regulatory mechanisms that evolved to align biological functions with the Earth's rotation. These rhythms are conserved across organisms from unicellular life to multicellular species and play essential roles in metabolism, immune responses, and sleep-wake cycle. Circadian disruptions are strongly associated with various diseases. Over the past decades, genetic studies in Drosophila and mice have identified key conserved clock genes and uncovered transcription-translation feedback loops governing circadian regulation. Additionally, rhythmic neurons in the brain integrate complex neural circuits to precisely regulate physiological and behavioral rhythms. This review highlights recent advances in understanding the neuronal circuit mechanisms of rhythmic neurons in the Drosophila brain and discusses future directions for translating circadian rhythm research into chronomedicine and precision therapies.
Animals ; Circadian Rhythm/genetics* ; Neurons/physiology* ; Drosophila/physiology* ; Brain/physiology* ; Nerve Net/physiology*

Sleep, an essential and evolutionarily conserved behavior, is regulated by numerous neurotransmitter systems. In mammals, glutamate serves as the wake-promoting signaling agent, whereas in Drosophila, it functions as the sleep-promoting signal. However, the precise molecular and cellular mechanisms through which glutamate promotes sleep remain elusive. Our study reveals that disruption of glutamate signaling significantly diminishes nocturnal sleep, and a neural cell-specific knockdown of the glutamate-gated chloride channel (GluClα) markedly reduces nocturnal sleep. We identified two pairs of neurons in the ventral nerve cord (VNC) that receive glutamate signaling input, and the GluClα derived from these neurons is crucial for sleep promotion. Furthermore, we demonstrated that GluClα mediates the glutamate-gated inhibitory input to these VNC neurons, thereby promoting sleep. Our findings elucidate that GluClα enhances nocturnal sleep by mediating the glutamate-gated inhibitory input to two pairs of VNC neurons, providing insights into the mechanism of sleep promotion in Drosophila.
Animals ; Sleep/physiology* ; Neurons/metabolism* ; Chloride Channels/genetics* ; Drosophila Proteins/genetics* ; Drosophila ; Glutamic Acid/metabolism* ; Animals, Genetically Modified

Background: Consumption and abuse of alcohol remains a significant cause of concern worldwide. Furthermore, there is evidence of the association between chronic alcohol use and reduced life expectancy. Objectives: To study the effects of Garcinia binucao extract (GBE) supplementation on lifespan of Drosophila melanogaster, in the presence or absence of chronic alcohol exposure. Methods: D. melanogaster was mass cultured and given GBE supplementation in high (1 mg/mL) and low (200 µg/mL) sublethal doses. D. melanogaster flies were divided into groups - with and without chronic alcohol exposure, and their respective lifespans were monitored. Results: In D. melanogaster without alcohol exposure, mean lifespan was highest in the control flies (38.15 days), followed by high-dose GBE (34.42 days), low-dose GBE (33.24 days), and DMSO (22.29 days). In D. melanogaster chronically exposed to alcohol, the longest mean lifespan was observed in flies treated with high-dose GBE (33.80 days), followed by low-dose GBE (33.63 days), the DMSO group (30.30), and the control group (29.65 days), but the differences were not statistically significant. Comparing groups with and without chronic alcohol exposure, the mean lifespan of the control group chronically exposed to alcohol significantly decreased by 9.51 days (p < 0.05). In GBE treatment groups, mean lifespan significantly decreased by 0.82 days in high-dose set-up (p < 0.05), and significantly increased by 0.39 days in the low-dose set-up (p < 0.05) upon chronic alcohol exposure. Conclusion Garcinia binucao extract supplementation ameliorated the observed reduction in lifespan of Drosophila melanogaster chronically exposed to alcohol.
Drosophila melanogaster ; Longevity

Introduction: Folkloric claims have surrounded essential oils, including their enhancement of learning and memory through inhalational exposure. Few studies in humans have shown a benefit in cognition, albeit incremental. However, this benefit may not be entirely attributable to the essential oil aroma but may be confounded by psychological associations. We investigated rosemary, peppermint, lemon, and coffee aromas in a learning and memory model of Drosophila melanogaster to eliminate this confounder. Methods: We screened for concentrations of the four treatments that are non-stimulatory for altered locomotory behavior in the flies. At these concentrations, we determined if they were chemoneutral (i.e., neither chemoattractant nor chemorepellent) to the flies. Learning and memory of the flies exposed to these aromas were determined using an Aversive Phototaxis Suppression (APS) assay. Results: The aromas of rosemary, peppermint, and lemon that did not elicit altered mobility in the flies were from dilute essential oil solutions that ranged from 0.2 to 0.5% v/v; whereas for the aroma in coffee, it was at a higher concentration of 7.5% m/v. At these concentrations, the aromas used were found to be chemoneutral towards the flies. We observed no improvement in both learning and memory in the four aromas tested. While a significant reduction (p < 0.05) in learning was observed when flies were treated with the aromas of rosemary, peppermint, and coffee, a significant reduction (p < 0.05) in memory was only observed in the peppermint aroma treatment. Conclusion This study demonstrated that in the absence of psychological association, the four aromas do not enhance learning and memory
Drosophila melanogaster ; Learning ; Memory ; Rosmarinus ; Mentha piperita ; Citrus ; Coffea

This study aims to explore the neuroprotective mechanism of ginsenoside Re(GS-Re) on drosophila model of Parkinson's disease(PD) induced by rotenone(Rot). To be specific, Rot was used to induce PD in drosophilas. Then the drosophilas were grouped and respectively treated(GS-Re: 0.1, 0.4, 1.6 mmol·L~(-1); L-dopa: 80 μmol·L~(-1)). Life span and crawling ability of drosophilas were determined. The brain antioxidant activity [content of catalase(CAT), malondialdehyde(MDA), reactive oxygen species(ROS), superoxide dismutase(SOD)], dopamine(DA) content, and mitochondrial function [content of adenosine triphosphate(ATP), NADH:ubiquinone oxidoreductase subunit B8(NDUFB8) Ⅰ activity, succinate dehydrogenase complex, subunit B(SDHB) Ⅱ activity] were detected by enzyme-linked immunosorbent assay(ELISA). The number of DA neurons in the brains of drosophilas was measured with the immunofluorescence method. The levels of NDUFB8 Ⅰ, SDHB Ⅱ, cytochrome C(Cyt C), nuclear factor-E2-related factor 2(Nrf2), heme oxygenase-1(HO-1), B-cell lymphoma/leukemia 2(Bcl-2)/Bcl-2-assaciated X protein(Bax), and cleaved caspase-3/caspase-3 in the brain were detected by Western blot. The results showed that model group [475 μmol·L~(-1) Rot(IC_(50))] demonstrated significantly low survival rate, obvious dyskinesia, small number of neurons and low DA content in the brain, high ROS level and MDA content, low content of SOD and CAT, significantly low ATP content, NDUFB8 Ⅰ activity, and SDHB Ⅱ activity, significantly low expression of NDUFB8 Ⅰ, SDHB Ⅱ, and Bcl-2/Bax, large amount of Cyt C released from mitochondria to cytoplasm, low nuclear transfer of Nrf2, and significantly high expression of cleaved caspase-3/caspase-3 compared with the control group. GS-Re(0.1, 0.4, and 1.6 mmol·L~(-1)) significantly improved the survival rate of PD drosophilas, alleviated the dyskinesia, increased DA content, reduced the loss of DA neurons, ROS level, and MDA content in brain, improved content of SOD and CAT and antioxidant activity in brain, maintained mitochondrial homeostasis(significantly increased ATP content and activity of NDUFB8 Ⅰ and SDHB Ⅱ, significantly up-regulated expression of NDUFB8 Ⅰ, SDHB Ⅱ, and Bcl-2/Bax), significantly reduced the expression of Cyt C, increased the nuclear transfer of Nrf2, and down-regulated the expression of cleaved caspase-3/caspase-3. In conclusion, GS-Re can significantly relieve the Rot-induced cerebral neurotoxicity in drosophilas. The mechanism may be that GS-Re activates Keap1-Nrf2-ARE signaling pathway by maintaining mitochondrial homeostasis, improves antioxidant capacity of brain neurons, then inhibits mitochondria-mediated caspase-3 signaling pathway, and the apoptosis of neuronal cells, thereby exerting the neuroprotective effect.
Animals ; Reactive Oxygen Species/metabolism* ; Antioxidants/pharmacology* ; Oxidative Stress ; NF-E2-Related Factor 2/metabolism* ; Caspase 3/metabolism* ; Parkinson Disease/genetics* ; bcl-2-Associated X Protein/metabolism* ; Neuroprotective Agents/pharmacology* ; Kelch-Like ECH-Associated Protein 1/metabolism* ; Drosophila/metabolism* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Apoptosis ; Superoxide Dismutase/metabolism* ; Adenosine Triphosphate/pharmacology*

Objective: To explore the impact of health management measures for entry personnel (entry management measures) against COVID-19 on the epidemiological characteristics of imported Dengue fever in Guangdong Province from 2020 to 2022. Methods: Data of imported Dengue fever from January 1, 2016 to August 31, 2022, mosquito density surveillance from 2016 to 2021, and international airline passengers and Dengue fever annual reported cases from 2011 to 2021 in Guangdong were collected. Comparative analysis was conducted to explore changes in the epidemic characteristics of imported Dengue fever before the implementation of entry management measures (from January 1, 2016 to March 20, 2020) and after the implementation (from March 21, 2020 to August 31, 2022). Results: From March 21, 2020, to August 31, 2022, a total of 52 cases of imported Dengue fever cases were reported, with an imported risk intensity of 0.12, which were lower than those before implementation of entry management measures (1 828, 5.29). No significant differences were found in the characteristics of imported cases before and after implementation of entry management measures, including seasonality, sex, age, career, and imported countries (all P>0.05). 59.62% (31/52) of cases were found at the centralized isolation sites and 38.46% (20/52) at the entry ports. However, before implementation of entry management measures, 95.08% (1 738/1 828) of cases were found in hospitals. Among 51 cases who had provided entry dates, 82.35% (42/51) and 98.04% (50/51) of cases were found within seven days and fourteen days after entry, slightly higher than before implementation [(72.69%(362/498) and 97.59% (486/498)]. There was significant difference between the monthly mean values of Aedes mosquito larval density (Bretto index) from 2020 to 2021 and those from 2016 to 2019 (Z=2.83, P=0.005). There is a strong positive correlation between the annual international airline passengers volume in Guangdong from 2011 to 2021 and the annual imported Dengue fever cases (r=0.94, P<0.001), and a positive correlation also existed between the international passenger volume and the annual indigenous Dengue fever cases (r=0.72, P=0.013). Conclusions: In Guangdong, the entry management measures of centralized isolation for fourteen days after entry from abroad had been implemented, and most imported Dengue fever cases were found within fourteen days after entry. The risk of local transmission caused by imported cases has reduced significantly.
Animals ; Humans ; COVID-19 ; Aedes ; Epidemics ; China/epidemiology* ; Dengue/epidemiology*

Females increase aggression for mating opportunities and for acquiring reproductive resources. Although the close relationship between female aggression and mating status is widely appreciated, whether and how female aggression is regulated by mating-related cues remains poorly understood. Here we report an interesting observation that Drosophila virgin females initiate high-frequency attacks toward mated females. We identify 11-cis-vaccenyl acetate (cVA), a male-derived pheromone transferred to females during mating, which promotes virgin female aggression. We subsequently reveal a cVA-responsive neural circuit consisting of four orders of neurons, including Or67d, DA1, aSP-g, and pC1 neurons, that mediate cVA-induced virgin female aggression. We also determine that aSP-g neurons release acetylcholine (ACh) to excite pC1 neurons via the nicotinic ACh receptor nAChRα7. Together, beyond revealing cVA as a mating-related inducer of virgin female aggression, our results identify a neural circuit linking the chemosensory perception of mating-related cues to aggressive behavior in Drosophila females.
Animals ; Male ; Female ; Drosophila/physiology* ; Drosophila Proteins/physiology* ; Cues ; Sexual Behavior, Animal/physiology* ; Aggression/physiology* ; Drosophila melanogaster/physiology*

OBJECTIVE: To analyze the density, distribution and insecticide resistance of Aedes albopictus in Ningbo City in 2021, so as to provide insights into formulation of dengue fever control strategies. METHODS: Four administrative villages were randomly selected from each county (district) in Ningbo City from April to November, 2021, to investigate the indoor population density of Aedes larvae, and the Breteau index (BI) was calculated. The population density of adult mosquitoes was investigated in residential areas, parks/bamboo forests, waste tire stacking sites/waste stations/construction sites in each county (district). On June 2021, larvae of the natural strain A. albopictus were collected from epidemic sites of dengue fever in Ningbo City in 2018, and raised in laboratory. Then, larvae and female mosquitoes without blood feeding were selected for insecticide resistance bioassays, while insecticide-sensitive strains of A. albopictus served as controls. The resistance of A. albopictus larvae to deltamethrin, beta-cypermethrin, propoxur, temephos and dichlorvos using the impregnation method, and the medium lethal concentration (LC₅₀) and resistance ratio (RR) were calculated. The resistance of adult A. albopictus to beta-cypermethrin, permethrin, deltamethrin, propoxur and malathion was determined using the tube bioassay, and the mosquito mortality was calculated. RESULTS: A total of 10 072 small water containers from 9 935 households were investigated in Ningbo City in 2021, and there were 1 276 containers with Aedes larvae detected, with an average BI of 12.89. Totally 1 422 mosquito nets were allocated and 954 female A. albopictus were captured, with an average net trapping index of 1.34 mosquitoes/(net·hour). Both larval and adult A. albopictus mosquitoes were found from April to November, and the density of larval A. albopictus peaked in September (BI = 21.21), while the density of adult A. albopictus peaked in August, with a net trapping index of 2.38 mosquitoes/(net·hour). The LC₅₀ values of delta-methrin, beta-cypermethrin, propoxur, temephos and dichlorvos were 0.017 4, 0.000 9, 0.364 1, 0.038 1 mg/L and 0.001 6 mg/L against larvae of natural strains of A. albopicchus, with RRs of 49.66, 25.53, 9.65, 2.24 and 6.06, and the mortality rates of adult mosquitoes were 66.00% (66/100), 69.39% (68/98), 25.00% (25/100), 98.97% (96/97) and 100.00% (98/98) 24 hours post-treatment with 0.08% beta-cypermethrin, 0.03% deltamethrin, 0.4% permethrin, 0.05% propoxur, and 0.5% malathion for 24 h, respectively. CONCLUSIONS A. albopictus is widely distributed in Ningbo City, with a high population density and presents high-level resistance to common pyrethroid insecticides. The population density and insecticide resistance of A. albopictus requires to be reinforced.
Animals ; Female ; Malathion ; Temefos ; Aedes ; Propoxur ; Permethrin ; Dichlorvos ; Mosquito Vectors ; Larva ; Dengue/prevention & control*

OBJECTIVE: To investigate the infection and genotypes of Wolbachia in common mosquito species in Henan Province, so as to provide insights into management of mosquito-borne diseases. METHODS: Aedes, Culex and Anopheles samples were collected from cowsheds, sheepfolds and human houses in Puyang, Nanyang City and Xuchang cities of Henan Province from July to September, 2022, and the infection of Wolbachia was detected. The 16S rDNA and wsp genes of Wolbachia were amplified and sequenced. Sequence alignment was performed using the BLAST software, and the obtained 16S rDNA gene sequence was compared with the sequence of the 16S rDNA gene in GenBank database. In addition, the phylogenetic trees were created based on 16S rDNA and wsp gene sequences using the software MEGA 11.0. RESULTS: A total 506 female adult mosquitoes were collected from three sampling sites in Nanyang, Xuchang City and Puyang cities from July to September, 2022. The overall detection of Wolbachia was 45.1% (228/506) in mosquitoes, with a higher detection rate in A. albopictus than in Cx. pipiens pallens [97.9% (143/146) vs. 50.6% (85/168); χ² = 88.064, P < 0.01]. The detection of Wolbachia in Cx. pipiens pallens was higher in Xuchang City (96.8%, 62/64) than in Nanyang (15.6%, 7/45) and Puyang cities (27.1%, 16/59) (χ² = 89.950, P < 0.01). The homologies of obtained Wolbachia 16S rDNA and wsp gene sequences were 95.3% to 100.0% and 81.7% to 99.8%. Phylogenetic analysis based on wsp gene sequences showed Wolbachia supergroups A and B in mosquito samples, with wAlbA and wMors strains in supergroup A and wPip and wAlbB strains in supergroup B. Wolbachia strain wAlbB infection was detected in A. albopictus in Puyang and Nanyang Cities, while Wolbachia strain wPip infection was identified in A. albopictus in Xuchang City. Wolbachia strain wAlbA infection was detected in Cx. pipiens pallens sampled from three cities, and one Cx. pipiens pallens was found to be infected with Wolbachia strain wMors in Nanyang City. CONCLUSIONS Wolbachia infection is commonly prevalent in Ae. albopictus and Cx. pipiens pallens from Henan Province, and Wolbachia strains wAlbB and wAlbA are predominant in Ae. albopictus, while wPip strain is predominant in Cx. pipiens pallens. This is the first report to present Wolbachia wMors strain infection in Cx. pipiens pallens in Henan Province.
Animals ; Humans ; Phylogeny ; Wolbachia/genetics* ; Culex/genetics* ; Aedes/genetics* ; DNA, Ribosomal