Filariasis Vector Research Articles

Xenorhabdus and Photorhabdus Bacteria as Potential Candidates for the Control of Culex pipiens L. (Diptera: Culicidae), the Principal Vector of West Nile Virus and Lymphatic Filariasis.

Vector-borne diseases pose a severe threat to human and animal health. Culex pipiens L. (Diptera: Culicidae) is a widespread mosquito species and serves as a vector for the transmission of infectious diseases such as West Nile disease and Lymphatic Filariasis. Synthetic insecticides have been the prime control method for many years to suppress Cx. pipiens populations. However, recently, the use of insecticides has begun to be questioned due to the detrimental impact on human health and the natural environment. Therefore, many authorities urge the development of eco-friendly control methods that are nontoxic to humans. The bacterial associates [Xenorhabdus and Photorhabdus spp. (Enterobacterales: Morganellaceae)] of entomopathogenic nematodes (EPNs) (Sterinernema spp. and Heterorhabditis spp.) (Rhabditida: Heterorhabditidae and Steinernematidae) are one of the green approaches to combat a variety of insect pests. In the present study, the mosquitocidal activity of the cell-free supernatants and cell suspension (4 × 107 cells mL-1) of four different symbiotic bacteria (Xenorhabdus nematophila, X. bovienii, X. budapestensis, and P. luminescens subsp. kayaii) was assessed against different development stages of Cx. pipiens (The 1st/2nd and 3rd/4th instar larvae and pupa) under laboratory conditions. The bacterial symbionts were able to kill all the development stages with varying levels of mortality. The 1st/2nd instar larvae exhibited the highest susceptibility to the cell-free supernatants and cell suspensions of symbiotic bacteria and the efficacy of the cell-free supernatants and cell suspensions gradually declined with increasing phases of growth. The highest effectiveness was achieved by the X. bovienii KCS-4S strain inducing 95% mortality to the 1st/2nd instar larvae. The results indicate that tested bacterial symbionts have great potential as an eco-friendly alternative to insecticides.

Molecular and morphometric differentiation of secondary filariasis vector Coquillettidia mosquitoes (Diptera: Culicidae) in Thailand.

Coquillettidia mosquitoes are important nuisance-biting pests and a vector of brugian filariasis in Thailand. However, comprehensive information about these mosquitoes remains unavailable such as molecular and morphometric differences among species. The lack of vector knowledge on Coquillettidia species could affect future disease control. This study aims to investigate differences in molecular variations based on mitochondrial cytochrome oxidase subunit I (COI) gene and wing geometric traits of three Coquillettidia species, namely Cq. crassipes, Cq. nigrosignata, and Cq. ochracea in Thailand. The results of molecular analyses revealed the differences among three Coquillettidia species. The genetic difference measure based on the Kimura two-parameter model among three Coquillettidia species showed low intraspecific distances (0%-3.05%) and large interspecific distances (10.10%-12.41%). The values of intra- and inter-genetic differences of three Coquillettidia species did not overlap which showed the existence of a barcoding gap indicating the efficiency of the identification based on the COI gene. As with molecular analysis, the landmark-based geometric morphometrics approach based on wing shape analysis indicated three distinct species groups which were supported by the high total performance score of cross-validated classification (97.16%). These results provide the first evidence of taxonomic signal based on molecular and wing geometric differences to support species identification and biological variations of Coquillettidia mosquitoes in Thailand for understanding these rare vector mosquitoes in depth and leading to effective further mosquito control.

Novel Essential Oils Blend as a Repellent and Toxic Agent against Disease-Transmitting Mosquitoes

Bio-insecticidal research has focused on long-term vector control using essential oils (EOs). This study examined the larvicidal, oviposition-deterrent, and repellent properties of five medicinal herb-based EO formulations (EOFs) on mosquitoes that are vectors of dengue, filariasis, and malaria. EOFs were significantly more toxic to the larvae and pupae of Culex quinquefasciatus, Anopheles stephensi, and Aedes aegypti with LC50 = 9.23, 12.85, and 14.46 ppm, as well with 10.22, 11.39, and 12.81 ppm, with oviposition active indexes of −0.84, −0.95, and −0.92, respectively. Oviposition-deterrent repellence was found in 91.39%, 94.83%, and 96.09%. EOs and N, N-Diethyl-3-methylbenzamide (DEET) were prepared at various concentrations for time duration repellent bioassays (6.25–100 ppm). Ae. aegypti, An. stephensi, and Cx. quinquefasciatus were monitored for 300, 270, and 180 min, respectively. At 100 ppm, EOs and DEET had comparable repellence in terms of test durations. EOF’s primary components d-limonene (12.9%), 2,6-octadienal, 3,7-dimethyl, (Z) (12.2%), acetic acid, phenylmethyl ester (19.6%), verbenol (7.6%), and benzyl benzoate (17.4%) may be combined to make a mosquito larvicidal and repellant equivalent to synthetic repellent lotions. In the molecular dynamics simulations, limonene (−6.1 kcal/mol) and benzyl benzoate (−7.5 kcal/mol) had a positive chemical association with DEET (−6.3 kcal/mol) and interacted with the OBP binding pocket with high affinity and stability. This research will help local herbal product manufacturers and the cosmetics industry in developing 100% herbal insect repellent products to combat mosquito-borne diseases, including dengue, malaria, and filariasis.

The Differences in Toxicity of Pletekan Leaf Extracts (Ruellia tuberosa L.) and Lime (Citrus auraiflia) on Mortality of Culex sp. Mosquito Larvae

Mosquitoes Culex sp. is the main vector of filariasis. Population control using chemical larvicides continuously can cause resistance. The leaves of the pletekan plant (Ruellia tuberosa L.) and lime fruit (Citrus aurantifolia) have the potential as natural larvicides. This study aims to determine the differences in high toxicity (LC50) of pletekan leaf extract and lime fruit on the mortality of Culex sp. mosquito larvae with an exposure time of 24 hours. Pletekan leaf extract and lime fruit were extracted by maceration using 97% ethanol. The LC50 can use probit analysis with SPSS applications. The results showed that pletekan leaves were toxic to Culex sp. mosquito larvae with an LC50 value of 710.169 ppm with the lowest concentration of 615.231 ppm and the highest concentration of 796.157 ppm. The LC50 value of lime fruit extract was 1026.749 ppm, with a lower limit of 846.406 ppm and an upper limit of 1294.531 ppm.

Efektifitas Variasi Konsentrasi Ekstrak Kulit Pisang Raja (Musa Paradisiaca var. Raja) Sebagai Biolarvasida Culex Sp.

Mosquitoes are vectors of disease and nuisance animals where Culex Sp mosquitoes are vectors of filariasis or elephantiasis. Vector control that has been carried out by the community generally uses chemical insecticides where if the use of chemical insecticides is carried out in the long term and continuously it can cause side effects on the environment, besides that it also causes resistance to the vector itself. This study aims to determine the effectiveness of the peel extract of plantain (Musa Paradisiaca var. Raja) as a larvicide on the mortality of Culex Sp. larvae. This research is an experimental research with The Static Group Comparassion Design. Total population and samples were 600 Culex Sp instar III larvae. The sampling method used random sampling method on Culex Sp instar III larvae or at the age of 3-4 days. Data analysis using Anova analysis using the STATA application. The results of the Anova test showed that there were differences in the mortality of Culex Sp with various doses of plantain peel extract (Musa Paradisiaca var. Raja), the highest effectiveness was 84% with an average mortality of 21 Culex Sp larvae, the conclusion of the study from probit analysis with an LC50 (Lethal Concentration) value of 2,969% and the most effective dose to kill Culex Sp larvae was at a dose of 8%.

Filariasis Vector Control Educational Model Trial to Elementary School Student in Pekalongan City

Anak usia sekolah merupakan generasi penerus bangsa yang harus dibekali dengan pengetahuan diharapkan dapat membentuk perilaku yang sehat dan produktif. Siswa terhindar dari penyakit dan kecacatan akibat micro filaria. Bermain dalam pembelajaran tidak hanya disukai oleh anak-anak, tetapi sangat bermanfaat bagi perkembangan anak, yang meliputi manfaat motorik, manfaat afeksi, manfaat kognitif, manfaat spiritual, dan manfaat keseimbangan. Tujuan uji validitas dan reliabilitas mengetahui perbedaan pengetahuan, sikap, praktik dan perilaku pengendalian vektor untuk pencegahan filariasis sebelum dan sesudah diberikan intervensi. Intervensi diberikan pada siswa kelas 5 di SDN 1 X di Kota Pekalongan jumlah 30 siswa. Uji bivariat mengunakan uji t Independent dan uji wilcoxon. sebagian besar variabel penilaian menunjukkan nilai p-value 0,05, pada nilai α 0,05, artinya terdapat perbedaan signifikan antara pretest dengan posttest. Hanya variabel perilaku tidur siang yang tidak memiliki perbedaan signifikan (p-value 0,073). Hasil evaluasi media permainan menunjukkan rentang rata-rata nilai antara 90,70 sampai dengan 95,00 dengan rata-rata nilai rata-rata terendah adalah untuk desain buku selamat datang sebesar 90,70 dan standard deviasi 11,50. Sedangkan nilai rata-rata tertinggi adalah untuk desain papan permainan yaitu sebesar 95,00 dan standard deviasi 10,40.

A DBHS family member regulates male determination in the filariasis vector Armigeres subalbatus

The initial signals governing sex determination vary widely among insects. Here we show that Armigeres subalbatus M factor (AsuMf), a male-specific duplication of an autosomal gene of the Drosophila behaviour/human splicing (DBHS) gene family, is the potential primary signal for sex determination in the human filariasis vector mosquito, Ar. subalbatus. Our results show that AsuMf satisfies two fundamental requirements of an M factor: male-specific expression and early embryonic expression. Ablations of AsuMf result in a shift from male- to female-specific splicing of doublesex and fruitless, leading to feminization of males both in morphology and general transcription profile. These data support the conclusion that AsuMf is essential for male development in Ar. subalbatus and reveal a male-determining factor that is derived from duplication and subsequent neofunctionalization of a member of the conserved DBHS family.

Morphological Characteristic of Adult Armigeres subalbatus from Sumbersari Jember

Armigeres subalbatus is a type of mosquito that is widely distributed in the world, including Jember Regency, Indonesia. The larval natural habitat is mainly found in trees that can hold water, adult mosquitoes can be found indoors or outdoors. In the field of health, Ar. subalbatus acts as a vector for filariasis, Japanese Encephalitis (JE) and zika. This study aims to identify the morphological characteristics of the Ar. subalbatus from Sumbersari Village, Jember Regency. Although in Indonesia there is no significant evidence of the role of Ar. subalbatus in the health sector, it is important to detect the morphological features of Ar. subalbatus to be able to detect mosquitoes properly. Knowing the exact type of mosquito can provide consideration for appropriate mosquito control methods. The method used is through the installation of ovitrap in November 2022. The ovitrap media is in the form of tap water, the ovitrap is left for 8 days. Ar. mosquitoes were found in the larval stage of the ovitrap. The larvae were brought to the Jember University Faculty of Mathematics and Natural Sciences Zoology Laboratory for hatching and data collection on the morphological characteristics of mosquitoes. The results of this study include the morphological characteristics used for the identification of Ar. subalbatus which includes the shape of the proboscis, flagelomeres on the palps, color of the scutum, border of the scutum, size of the antepronotum, bands on the pleura, prespiracular and postspiracular areas, edges of the mesepimeron, abdomen (tergum, sterna), apex of the femur, venation of the wings, alula and upper calypter of the wings.

Evaluation of the evolutionary genetics and population structure of Culex pipiens pallens in Shandong province, China based on knockdown resistance (kdr) mutations and the mtDNA-COI gene

BackgroundMosquitoes are important vectors for a range of diseases, contributing to high rates of morbidity and mortality in the human population. Culex pipiens pallens is dominant species of Culex mosquito in northern China and a major vector for both West Nile virus and Bancroftian filariasis. Insecticide application were largely applied to control the mosquito-mediated spread of these diseases, contributing to increasing rates of resistance in the mosquito population. The voltage-gated sodium channel (Vgsc) gene is the target site of pyrethroids, and mutations in this gene cause knockdown resistance (kdr). While these kdr mutations are known to be critical to pyrethroid resistance, their evolutionary origins remain poorly understood. Clarifying the origins of these mutations is potential to guide further vector control and disease prevention efforts. Accordingly, the present study was designed to study the evolutionary genetics of kdr mutations and their association with the population structure of Cx. p. pallens in Shandong province, China.MethodsAdult Culex females were collected from Shandong province and subjected to morphological identification under a dissection microscope. Genomic DNA were extracted from the collected mosquitoes, the Vgsc gene were amplified via PCR and sequenced to assess kdr allele frequencies, intron polymorphisms, and kdr codon evolution. In addition, population genetic diversity and related population characteristics were assessed by amplifying and sequencing the mitochondrial cytochrome C oxidase I (COI) gene.ResultsTotally, 263 Cx. p. pallens specimens were used for DNA barcoding and sequencing analyses to assess kdr allele frequencies in nine Culex populations. The kdr codon L1014 in the Vgsc gene identified two non-synonymous mutations (L1014F and L1014S) in the analyzed population. These mutations were present in the eastern hilly area and west plain region of Shandong Province. However, only L1014F mutation was detected in the southern mountainous area and Dongying city of Shandong Province, where the mutation frequency was low. Compared to other cities, population in Qingdao revealed significant genetic differentiation. Spatial kdr mutation patterns are likely attributable to some combination of prolonged insecticide-mediated selection coupled with the genetic isolation of these mosquito populations.ConclusionsThese data suggest that multiple kdr alleles associated with insecticide resistance are present within the Cx. p. pallens populations of Shandong Province, China. The geographical distributions of kdr mutations in this province are likely that the result of prolonged and extensive insecticide application in agricultural contexts together with frequent mosquito population migrations. In contrast, the low-frequency kdr mutation detected in central Shandong Province populations may originate from the limited selection pressure in this area and the relative genetic isolation. Overall, the study compares the genetic patterns revealed by a functional gene with a neutral marker and demonstrates the combined impact of demographic and selection factors on population structure.

Bio-efficacy of insecticidal molecule emodin against dengue, filariasis, and malaria vectors.

Emodin, a compound isolated from Aspergillusterreus, was studied using chromatographic and spectroscopic methods and compound purity (96%) was assessed by TLC. Furthermore, high larvicidal activity against Aedes aegypti-AeA (LC50 6.156 and LC90 12.450mg/L), Culex quinquefasciatus-CuQ (8.216 and 14.816mg/L), and Anopheles stephensi-AnS larvae (6.895 and 15.24mg/L) was recorded. The first isolated fraction (emodin) showed higher pupicidal activity against AeA (15.449 and 20.752mg/L). Most emodin-treated larvae (ETL) showed variations in acetylcholine esterase, α and β-carboxylesterases, and phosphatase activities in the 4th instar, indicating the intrinsic differences in their biochemical changes. ETL had numerous altered tissues, including muscle, gastric caeca, hindgut, midgut, nerve ganglia, and midgut epithelium. Acute toxicity of emodin on brine shrimp Artemia nauplii (54.0 and 84.5mg/L) and the zebrafish Danio rerio (less toxicity observed) was recorded. In docking studies, Emodin interacted well with odorant-binding-proteins of AeA, AnS, and CuQ with docking scores of - 8.89, - 6.53, and - 8.09kcalmol-1, respectively. Therefore, A. terreus is likely to be effective against mosquito larvicides.

Michelia champaca seed extract: A novel mosquitocide against the filarial vector Culex quinquifasciatus

Vector control is in risk as a result of the advent of synthetic pesticide resistance. Plant derived insecticides may be used as future bio control alternatives due to their target specificity and biodegradability. The aim of the present study was to determine the efficacy of Chloroform: Methanolic extract of Michelia champaca seeds against all the larval instars of Culex quinquifasciatus, the vector of Bancroftian filariasis. Chloroform: Methanolic extract showed remarkable larvicidal properties with LC50 and LC90 values as low as 15.33 ppm and 29.77 ppm recorded against the first instar larvae after 72 hours of treatment. There was a clear dose dependent increment in the death rate, which was positively correlated with the solvent concentration and had regression coefficient values close to 1. Because the investigated non-target organisms were unaffected, the plant-based mosquitocide that was thus discovered was proved to be environment friendly. FTIR analysis revealed the presence of various functional groups in the TLC fraction such as alcohol, alkane, methyl group, amine, aromatics, carboxylic acid and ether. So, M. champaca seeds extract can be proclaimed as an outstanding larvicidal agent against Cx. quinquifasciatus, and can serve as a source of potent mosquito larvicide in the near future.

Seaweed Sargassum wightii mediated preparation of TiO2 nanoparticles, larvicidal activity against malaria and filariasis vectors, and its effect on non-target organisms

Malaria and Lymphatic filariasis are considered significant public health concerns in several countries. As a researcher, controlling those mosquitos using safe and eco-friendly insecticides is essential. Thus, we aimed to explore the potential use of seaweed Sargassum wightii for the biosynthesis of TiO2 NPs and evaluate its efficiency in controlling disease-transmitting mosquito larvae (using Anopheles subpictus and Culex quinquefasciatus larvae as model systems (in vivo)) as well as its potential effect on non-target organisms (using Poecilia reticulata fish as an experimental model). XRD, FT-IR, SEM-EDAX, and TEM carried out the characterization of TiO2 NPs. It evaluated the larvicidal activity against the fourth instar larvae of A. subpictus and C. quinquefasciatus. The larvicidal mortality was observed after 24 h of exposure to S. wightii extract and TiO2 NPs. S. wightii synthesized TiO2 NPs show excellent activity against A. subpictus and C. quinquefasciatus (LC50 = 4.37 and 4.68; LC90 = 8.33 and 8.97; χ2 = 5.741 and 4.531) mg/L respectively. The GC-MS results indicate the presence of some important long-chain phytoconstituents like linoleic acid, palmitic acid, oleic acid methyl ester, and stearic acid, among others. Furthermore, when testing the possible toxicity of biosynthesized NPs in a non-target organism, no adverse effects were observed in Poecilia reticulata fish exposed for 24 h, considering the evaluated biomarkers. Thus, overall, our study results reveal that biosynthesized TiO2 NPs are an effective and exciting eco-friendly approach to controlling the A. subpictus and C. quinquefasciatus.

Larvicidal Activities of Allium sativum L. and Zingiber officinale Rosc. Extracts against Filariasis Vectors in Hadiya Zone, Ethiopia.

Mosquitoes present an immense threat to millions of people worldwide and act as vectors for filariasis disease. The objective of the study was to determine the effect of Allium sativum and Zingiber officinale extracts against filariasis vectors. The larvae were collected from the breeding site by using standard procedures for identification and larvicidal activities. Twenty grams (20 g) from each (Allium sativum and Zingiber officinale) were extracted separately by aqueous, ethanol, and methanol solvents. The phytochemical analysis was determined in the crude sample by using standard methods. Then, larvicidal effects were determined by introducing 10 larvae of the vectors to the concentrations of 250 ppm, 500 ppm, and 750 ppm of the crude sample, and data were subjected to probit analysis to determine the LC50 and Chi-squared test to check the significance of the mortality by R software. Anopheles funestus, Anopheles gambiae s.l., Anopheles pharoensis, Culex antennatus, and Culex quinquefasciatus were the filariasis vectors identified during the study period. The presence of phytochemical tests such as anthraquinones, flavonoids, glycosides, phenol, saponin, steroids, tannin, and terpenes was obtained. The larvicidal effects of the selected plant extracts ranged from 0%-100%. The lowest LC50 (53 ppm) was observed for A. sativum methanol test extract against Cx. quinquefasciatus. Ethanol extracts of A. sativum have a significant effect on An. funestus (X2 = 7.5, p = 0.02352) and Cx. quinquefasciatus (X2 = 10.833, p = 0.0.0044), whereas aqueous extracts have a significant effect only on An. gambiae s.l. (X2 = 7.0807, p = 0.029. Ethanol extracts of Z. officinale have a significant effect only on the mortality of An. pharoensis (X2 = 7.0807, p = 0.029), but methanol and aqueous extracts have no significant effect against filariasis vectors. In conclusion, A. sativum have a high toxic effect than Z. officinale extract against filariasis vectors in all type of solvents. So using those plant extracts is the best to reduce the risk of the synthetic chemical on nontarget organisms and the environment, in addition to the control of mosquito-borne diseases, but further studies will be conducted to evaluate the toxicity at different stages of the vectors.

Prospective of Green waste compounds against Dengue vector Aedes aegypti and Filariasis vector Culex quinquefasciatus

Prospective of Green waste compounds against Dengue vector Aedes aegypti and Filariasis vector Culex quinquefasciatus

Chemical constituents and strong larvicidal activity of Solanum xanthocarpum among selected plants extracts against the malaria, filaria, and dengue vectors.

The role of mosquitoes is instrumental in the transmission of various diseases. Mosquitoe-borne diseases account for a significant share of the global burden of total infectious diseases. Vector control is the principal method for the control of these mosquito-borne diseases. Plant-derived insecticides serve as an effective alternative to chemical insecticides. The present study has been undertaken to assess the larvicidal potential of methanol and petroleum ether extracts of leaves of Solanum xanthocarpum, Parthenium hysterophorus, Manihot esculenta, and Chamaecyparis obtusa. Larvicidal activity was tested against the early four-stage instar larvae of laboratory-reared susceptible strains of the malaria vector, Anopheles stephensi, dengue fever vector, Aedes aegypti, and the lymphatic filariasis vector, Culex quinquefasciatus at 20 to 120 ppm concentrations. Further, liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectroscopy (GC-MS) analyses were carried out to identify the bioactive compounds present in the methanolic leaf extracts of Solanum xanthocarpum for designing a larvicidal product in future. After 72 h of exposure high larvicidal activities were observed in methanolic and petroleum ether leaves extract of S. xanthocarpum against An. stephensi, Ae. aegypti and Cx. quinquefasciatus. The larvicidal activities for methanol and petroleum ether leaf extract of S. xanthocarpum with LC50 = 09.201 and 12.435 ppm and LC90 = 21.578 and 27.418 ppm for An. stephensi; LC50 = 11.450 and 10.026 ppm and LC90 = 26.328 and 22.632 ppm for Ae. aegypti and LC50 = 12.962 and 13.325 ppm and LC90 = 26.731 and 30.409 ppm for Cx. quinquefasciatus, respectively, were found to be most effective. GC-MS analysis revealed 43 compounds, amongst these phytol (13.09%), 3-allyl-2-methoxy phenol (9.55%), (9Z, 12Z)-9, 12-octadecadienoyl chloride (7.93%), linoleic acid (5.45%), alpha-tocospiro B (5.08%) and hexadecanoic acid (4.35%) were identified as major compounds. Present work showed that leaf extracts of S. xanthocarpum are a source of potential natural candidate that possess several phytochemicals which can be explored further for the development of ecologically safer mosquito control products.

Larvicidal Effect of Hyptis suaveolens (L.) Poit. Essential Oil Nanoemulsion on Culex quinquefasciatus (Diptera: Culicidae).

Mosquitoes can be vectors of pathogens and transmit diseases to both animals and humans. Species of the genus Culex are part of the cycle of neglected diseases, especially Culex quinquefasciatus, which is an anthropophilic vector of lymphatic filariasis. Natural products can be an alternative to synthetic insecticides for vector control; however, the main issue is the poor water availability of some compounds from plant origin. In this context, nanoemulsions are kinetic stable delivery systems of great interest for lipophilic substances. The objective of this study was to investigate the larvicidal activity of the Hyptis suaveolens essential oil nanoemulsion on Cx. quinquefasciatus. The essential oil showed a predominance of monoterpenes with retention time (RT) lower than 15 min. The average size diameter of the emulsions (sorbitan monooleate/polysorbate 20) was ≤ 200 nm. The nanoemulsion showed high larvicidal activity in concentrations of 250 and 125 ppm. CL50 values were 102.41 (77.5253−149.14) ppm and 70.8105 (44.5282−109.811) ppm after 24 and 48 h, respectively. The mortality rate in the surfactant control was lower than 9%. Scanning micrograph images showed changes in the larvae’s integument. This study achieved an active nanoemulsion on Cx. quinquefasciatus through a low-energy-input technique and without using potentially toxic organic solvents. Therefore, it expands the scope of possible applications of H. suaveolens essential oil in the production of high-added-value nanosystems for tropical disease vector control.

RNAi-mediated knockdown of arginine kinase genes leads to high mortality and negatively affect reproduction and blood-feeding behavior of Culex pipiens pallens.

Arginine kinase (AK) is one of the crucial enzymes involved in energy metabolism in invertebrates, and has been proposed as the target for RNA interference (RNAi)-based control of agricultural insect pests. While there is only one AK gene in most insects, two AK genes were identified in Culex pipiens pallens, the primary vector of lymphatic filariasis and epidemic encephalitis. The full-length cDNA sequences of CpAK1 and CpAK2 genes were obtained by reverse transcription PCR(RT-PCR) and rapid amplification of cDNA ends (RACE). The expression levels of CpAK1 and CpAK2 in different developmental stages and tissues were detected by reverse transcription quantitative PCR (RT-qPCR). The role of CpAK1 and CpAK2 in the reproduction and blood feeding behavior was analyzed using RNA interference (RNAi). Full-length cDNAs of CpAK1 and CpAK2 were isolated from Cx. pipiens pallens. Analysis of the expression pattern revealed that the mRNA level of CpAK1 was significantly higher than CpAK2 in all development stages and tissues examined, and the expressions of both CpAK1 and CpAK2 were upregulated in response to blood feeding. The co-knockdown of CpAK1 and CpAK2 mediated by RNAi led to high mortality (74.3%) of adult female mosquitoes and decreased hatchability (59.9%). Remarkably, the blood feeding rate and the engorgement rate of the female mosquitoes were negatively affected by co-injection of dsRNAs targeting CpAK1 and CpAK2. CpAK1 and CpAK2 were detected in all developmental stages and tissues, but showed divergence in expression level. RNAi-mediated knockdown of AK genes leads to high mortality and negatively affect blood-feeding behavior of Cx. pipiens pallens, suggesting that AK could be used for the target of RNAi-based mosquito control in the future.

Uji Efektivitas Larvasida Ekstrak Daun Pegagan (Centella asiatica L. Urban) Terhadap Larva Culex quinquefasciatus

Culex quinquefasciatus is a vector of filariasis (elephantiasis) and Japanese encephalitis. Filariasis is still an unresolved disease in Indonesia. The use of temephos as a chemical larvicide repeatedly causes environmental pollution and is difficult to decompose, so the World Health Organization recommends looking for alternative effects. Gotu kola leaf extract contains metabolic substances such as steroids,saponins, flavonoids, phenolics that can be used as larvicides. This study aimed to determine the effectiveness of the larvicide extract of pegagan (Centella asiatica L. Urban) on the mortality of Culex quinquefasciatus larvae. This study used an experimental research design with a posttest only control group design using 4 concentration groups and 2 control groups, consisting of 4 repetitions in each, namely concentrations of 125 ppm, 250 ppm, 500 ppm, 1000 ppm, abate positive control and aquadest negative control. with the mean larval mortality was 31%, 65%, 81%, 98% which was observed for 48 hours. The number of larval deaths was analyzed using the Kruskall-Wallis test and logit analysis. The results of the analysis showed that pegagan leaf extract had an effect on the mortality of Culex quinquefasciatus larvae with a significant value (p < 0.05), then the results of logit regression analysis showed the LC50 value of 206.71 ppm. The conclusion of this study was that the leaf extract of pegagan (Centella asiatica L. Urban) was effective against the mortality of Culex quinquefasciatus larvae.

Uji Efektivitas Larvasida Ekstrak Daun Pegagan (Centella asiatica L. Urban) Terhadap Larva Culex quinquefasciatus

Culex quinquefasciatus is a vector of filariasis (elephantiasis) and Japanese encephalitis. Filariasis is still an unresolved disease in Indonesia. The use of temephos as a chemical larvicide repeatedly causes environmental pollution and is difficult to decompose, so the World Health Organization recommends looking for alternative effects. Gotu kola leaf extract contains metabolic substances such as steroids,saponins, flavonoids, phenolics that can be used as larvicides. This study aimed to determine the effectiveness of the larvicide extract of pegagan (Centella asiatica L. Urban) on the mortality of Culex quinquefasciatus larvae. This study used an experimental research design with a posttest only control group design using 4 concentration groups and 2 control groups, consisting of 4 repetitions in each, namely concentrations of 125 ppm, 250 ppm, 500 ppm, 1000 ppm, abate positive control and aquadest negative control. with the mean larval mortality was 31%, 65%, 81%, 98% which was observed for 48 hours. The number of larval deaths was analyzed using the Kruskall-Wallis test and logit analysis. The results of the analysis showed that pegagan leaf extract had an effect on the mortality of Culex quinquefasciatus larvae with a significant value (p < 0.05), then the results of logit regression analysis showed the LC50 value of 206.71 ppm. The conclusion of this study was that the leaf extract of pegagan (Centella asiatica L. Urban) was effective against the mortality of Culex quinquefasciatus larvae.

Novel genome sequences and evolutionary dynamics of the North American anopheline species Anopheles freeborni, Anopheles crucians, Anopheles quadrimaculatus, and Anopheles albimanus.

Anopheles mosquitoes are the principal vectors for malaria and lymphatic filariasis, and evidence for arboviral transmission under laboratory and natural contexts has been demonstrated. Vector management approaches require an understanding of the ecological, epidemiological, and biological contexts of the species in question, and increased interest in gene drive systems for vector control applications has resulted in an increased need for genome assemblies from understudied mosquito vector species. In this study, we present novel genome assemblies for Anopheles crucians, Anopheles freeborni, Anopheles albimanus, and Anopheles quadrimaculatus and examine the evolutionary relationship between these species. We identified 790 shared single-copy orthologs between the newly sequenced genomes and created a phylogeny using 673 of the orthologs, identifying 289 orthologs with evidence for positive selection on at least 1 branch of the phylogeny. Gene ontology terms such as calcium ion signaling, histone binding, and protein acetylation identified as being biased in the set of selected genes. These novel genome sequences will be useful in developing our understanding of the diverse biological traits that drive vectorial capacity in anophelines.