scholarly journals Repellency of Veratraldehyde (3,4-Dimethoxy Benzaldehyde) against Mosquito Females and Tick Nymphs

2021 ◽  
Vol 11 (11) ◽  
pp. 4861
Author(s):  
Soon-Il Kim ◽  
Jun-Hyung Tak ◽  
Jeong Kyu Seo ◽  
Seong Ryel Park ◽  
Jiwon Kim ◽  
...  
Keyword(s):  
Culex Pipiens ◽  
Pharmacokinetic Parameters ◽  
Control Group ◽  
Haemaphysalis Longicornis ◽  
Culex Pipiens Pallens ◽  
Protection Time ◽  
Near Future ◽  
Mosquito Females ◽  
Pipiens Pallens ◽  
Better Than

Arthropod-borne infectious diseases cause many deaths and a major economic burden worldwide. Repellents play an important role in protecting people from infectious biting arthropods. The repellency of veratraldehyde, a known food additive, and the WJ-1041 formulation containing 10% veratraldehyde was tested against Aedes albopictus and Culex pipiens pallens females and Haemaphysalis longicornis nymphs using arm-in-cage, indoor or filter paper tests. Veratraldehyde exhibited repellency similar to or lower than that of n,n-diethyl-meta-toluamide (DEET) against A. albopictus, but in H. longicornis, the activity of veratraldehyde was better than that of DEET. The repellency of the 10% veratraldehyde solution was comparable to that of 20% DEET against the two mosquitoes. When comparing repellency between the WJ-1041 formulation (10% veratraldehyde) and 10% DEET against C. pipiens pallens, A. Albopictus and H. longicornis, the two showed similar repellency and complete protection time (CPT) values. However, there was a small difference depending on the tested insects. The absorption of veratraldehyde via skin was minimal, if at all. The pharmacokinetic parameters (Cmax and Tmax) of veratraldehyde in blood samples of rats were not different from those of the control group. Based on these results, veratraldehyde has high potential to be commercialized as a repellent agent against infectious disease-borne pests in the near future.

scholarly journals Microbiota and transcriptome changes of Culex pipiens pallens larvae exposed to Bacillus thuringiensis israelensis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ruiling Zhang ◽  
Wenjuan Liu ◽  
Qian Zhang ◽  
Xinyu Zhang ◽  
Zhong Zhang
Keyword(s):  
Bacillus Thuringiensis ◽  
Culex Pipiens ◽  
Mosquito Control ◽  
Sphingolipid Metabolism ◽  
Glutathione Metabolism ◽  
Control Group ◽  
Culex Pipiens Pallens ◽  
Bacillus Thuringiensis Israelensis ◽  
Epidemic Encephalitis ◽  
Pipiens Pallens

AbstractCulex pipiens pallens is an important vector of lymphatic filariasis and epidemic encephalitis. Mosquito control is the main strategy used for the prevention of mosquito-borne diseases. Bacillus thuringiensis israelensis (Bti) is an entomopathogenic bacterium widely used in mosquito control. In this study, we profiled the microbiota and transcriptional response of the larvae of Cx. pipiens pallens exposed to different concentrations of Bti. The results demonstrated that Bti induced a significant effect on both the microbiota and gene expression of Cx. pipiens pallens. Compared to the control group, the predominant bacteria changed from Actinobacteria to Firmicutes, and with increase in the concentration of Bti, the abundance of Actinobacteria was gradually reduced. Similar changes were also detected at the genus level, where Bacillus replaced Microbacterium, becoming the predominant genus in Bti-exposed groups. Furthermore, alpha diversity analysis indicated that Bti exposure changed the diversity of the microbota, possibly because the dysbiosis caused by the Bti infection inhibits some bacteria and provides opportunities to other opportunistic taxa. Pathway analysis revealed significant enhancement for processes associated with sphingolipid metabolism, glutathione metabolism and glycerophospholipid metabolism between all Bti-exposed groups and control group. Additionally, genes associated with the Toll and Imd signaling pathway were found to be notably upregulated. Bti infection significantly changed the bacterial community of larvae of Cx. pipiens pallens.

CPR63 Promotes Pyrethroid Resistance by Increasing Cuticle Thickness in Culex Pipiens Pallens

2021 ◽  
Author(s):  
Yang Xu ◽  
Yang Zhou ◽  
Xixi Li ◽  
Lei Ma ◽  
Dan Zhou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Culex Pipiens ◽  
Pyrethroid Resistance ◽  
Resistance Mechanism ◽  
Negative Control Group ◽  
Negative Control ◽  
Control Group ◽  
Culex Pipiens Pallens ◽  
Cuticle Thickness ◽  
Pipiens Pallens

Abstract The cuticle protein (CP) encoded by CPR63 plays a role in deltamethrin resistance in Culex pipiens pallens. Herein, we investigated the distribution of CPR63 transcripts in this organism, and revealed high expression levels in legs and wings. Furthermore, expression of CPR63 in the legs of deltamethrin-resistant (DR) strains were 1.79-fold higher than in deltamethrin-susceptible (DS) strains. Cuticle analysis of small interfering RNA (siRNA) groups by scanning electron microscopy (SEM) revealed a significantly thinner procuticle of the tarsi in the siCPR63 group than the siNC (negative control (group). Transmission electron microscopy (TEM) revealed that the procuticle, exocuticle and endocuticle thickness of the tarsi were significantly thinner in the siCPR63 group than the siNC group. Our results illuminate the resistance mechanism of CPRs and demonstrate that CPR63 contributes to the resistance phenotype by thickening the cuticle and substantially reducing uptake of insecticides.

scholarly journals MiR-4448 is involved in deltamethrin resistance by targeting CYP4H31 in Culex pipiens pallens

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Xixi Li ◽  
Shengli Hu ◽  
Haitao Yin ◽  
Hongbo Zhang ◽  
Dan Zhou ◽  
...  
Keyword(s):  
Culex Pipiens ◽  
Oral Feeding ◽  
Cell Counting ◽  
Luciferase Reporter ◽  
Culex Pipiens Pallens ◽  
Deltamethrin Resistance ◽  
Regulatory Functions ◽  
Pipiens Pallens

Abstract Background Culex pipiens (Cx. pipiens) complex, which acts as a vector of viruses and is widespread and abundant worldwide, including West Nile virus, Japanese encephalitis virus, and Sindbis virus, can cause serious vector-borne diseases affecting human health. Unfortunately, mosquitoes have developed deltamethrin resistance because of its long-term overuse, representing a major challenge to mosquito control. Understanding the molecular regulatory mechanisms of resistance is vital to control mosquitoes. MicroRNAs (miRNAs) are short non-coding RNAs that have been demonstrated to be important regulators of gene expression across a wide variety of organisms, which might function in mosquito deltamethrin resistance. In the present study, we aimed to investigate the regulatory functions of miR-4448 and CYP4H31 in the formation of insecticidal resistance in mosquito Culex pipiens pallens. Methods We used quantitative real-time reverse transcription PCR to measure miR-4448 and CYP4H31 (encoding a cytochrome P450) expression levels. The regulatory functions of miR-4448 and CYP4H31 were assessed using dual-luciferase reporter assays. Then, oral feeding, RNA interference, and the American Centers for Disease Control and Prevention bottle bioassay were used to determine miR-4448’s association with deltamethrin resistance by targeting CYP4H31in vivo. Cell Counting Kit-8 (CCK-8) was also used to detect the viability of pIB/V5-His-CYP4H31-transfected C6/36 cells after deltamethrin treatment in vitro. Results MiR-4448 was downregulated in the deltamethrin-resistant strain (DR strain), whereas CYP4H31 was downregulated in deltamethrin-susceptible strain. CYP4H31 expression was downregulated by miR-4448 recognizing and binding to its 3′ untranslated region. Functional verification experiments showed that miR-4448 overexpression resulted in lower expression of CYP4H31. The mortality of miR-4448 mimic-injected DR strain mosquitoes was higher than that of the controls. CCK-8 assays showed that CYP4H31 decreased cellular resistance to deltamethrin in vitro and the mortality of the DR strain increased when CYP4H31 was knocked down in vivo. Conclusions In mosquitoes, miR-4448 participates in deltamethrin resistance by targeting CYP4H31. The results of the present study increase our understanding of deltamethrin resistance mechanisms.

Feeding on different attractive flowering plants affects the energy reserves of Culex pipiens pallens adults

2017 ◽  
Vol 117 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Bao-Ting Yu ◽  
Yin Hu ◽  
Yan-Mei Ding ◽  
Jia-Xin Tian ◽  
Jian-Chu Mo
Keyword(s):  
Culex Pipiens ◽  
Flowering Plants ◽  
Energy Reserves ◽  
Culex Pipiens Pallens ◽  
Pipiens Pallens

scholarly journals Cloning and Expression of Two Crystal Protein Genes, cry30Ba1 and cry44Aa1, Obtained from a Highly Mosquitocidal Strain, Bacillus thuringiensis subsp. entomocidus INA288

2006 ◽  
Vol 72 (8) ◽  
pp. 5673-5676 ◽  
Author(s):  
Takeshi Ito ◽  
Tomonori Ikeya ◽  
Ken Sahara ◽  
Hisanori Bando ◽  
Shin-ichiro Asano
Keyword(s):  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Culex Pipiens ◽  
Crystal Protein ◽  
Cloning And Expression ◽  
Culex Pipiens Pallens ◽  
Bacillus Thuringiensis Subsp ◽  
Pipiens Pallens ◽  
Crystal Protein Genes

ABSTRACT Two novel crystal protein genes, cry30Ba and cry44Aa, were cloned from Bacillus thuringiensis subsp. entomocidus INA288 and expressed in an acrystalliferous strain. Cry44Aa crystals were highly toxic to second-instar Culex pipiens pallens (50% mortality concentration [LC50] = 6 ng/ml) and Aedes aegypti (LC50 = 12 ng/ml); however, Cry30Ba crystals were not toxic.

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