Hitting the right note at the right time: Circadian control of audibility in Anopheles mosquito mating swarms is mediated by flight tones

By beating their wings faster around sunset, male Anopheles mosquitoes sensitize their auditory system to female flight tones.

Adult Anopheles Mosquito Distribution at a Low and High Malaria Transmission Site in Tanzania

Malaria parasites are only transmitted by female mosquitoes of the genus Anopheles; hence, the disease’s distribution is linked to that of the vector mosquitoes. As such, the goal of this study was to find out the spatial and temporal distribution of Anopheles mosquito adults in the research sites. This was a repeated cross-sectional ecological study that took place in Morogoro and Dodoma, Tanzania. Vacuum aspiration was used to collect mosquitoes both outside and inside human dwellings. All mosquito-related data was collected and entered into appropriate data collection forms. Female mosquitoes were recognized morphologically using Gillies and Coetzee morphological criteria, followed by PCR. In total, about 2742 Anopheles mosquitoes with an average collection of 18.21 ± 1.12 per day were collected outside human houses of which 1717 ( 10.51 ± 1.17 ) and 1025 ( 8.42 ± 1.41 ) were collected from Morogoro and Dodoma, respectively. Of the captured mosquitoes, 89.0%, 10.0%, and 1.0% were recognized as Anopheles arabiensis, Anopheles gambiae s.s., and Anopheles quadrianulatus, respectively. The distribution varied significantly with seasons, whereby 302 ( 4.72 ± 1.04 ) and 2440 ( 12.96 ± 1.52 ) mosquitoes were captured in the cold-dry and warm-wet season, respectively ( p < 0.0001 ). Of the captured mosquitoes, 42.33%, 16.33%, 14.96%, and 4.27 were found on the ceiling, stored junks, verandas, and barks/tree, respectively. In malaria-endemic countries, vector control forms an important component of the malaria control efforts. This study found significant variation of Anopheles mosquito abundance in time and space with Anopheles arabiensis being the most predominant malaria vector. This signifies the need to introduce mosquito control methods that will target the less anthropophilic Anopheles arabiensis or the immature aquatic stages. The study further found that underbeds, store room/piled bags, and undisturbed curtains were the most preferred resting places by mosquitoes signifying to be the most effective strategic sites for spraying insecticides during the implementation of indoor residual spraying (IRS).

Preparation and Optimization of Peppermint (Mentha Pipertia) Essential Oil Nanoemulsion with Effective Herbal Larvicidal, Pupicidal, and Ovicidal Activity against Anopheles Stephensi

Objectives: The Plasmodium parasite is transmitted directly to humans through the Anopheles mosquito bite and causes vector-borne Malaria disease, which leads to the transmission of the disease in Southeast Asia, including India. The problem of persistent toxicity, along with the growing incidence of insect resistance, has led to the use of green pesticides to control the spread of the disease in a cost-effective and environment-friendly manner. Based on this objective, this work investigated the larvicidal, pupicidal, and ovicidal activity of Mentha pipertia using a natural nanoemulsion technique. Methods: GC-MS characterized essential oils of Mentha pipertia leaves were formulated as a nanoemulsion for herbal larvicidal, pupicidal, and ovicidal activities. Size of the nanoemulsion was analyzed by photon correlation spectroscopy. The herbal activities against Anopheles Stephensi of nanoemulsion were evaluated in terms of the lethal concentration for 50% (LC50) and 90% (LC90) to prove low cost, pollution free active effective formulation. Results: Chiral, keto, and alcohol groups attached Mentha pipertia leaves essential oil nanoemulsions demonstrated good results in the larvicidal probit analysis, with values of LC50=09.67 ppm and LC90=20.60 ppm. Activity results of the most stable nano formulation with 9.89 nm size showed a significant increase when compared to the bulk. Conclusion: The nanoemulsion of Mentha pipertia leaves can be a promising eco-friendly widely available, low-cost herbicide against the Anopheles mosquito.

Molecular Diversity of Bacillus thuringiensis and Bioinformatics Analysis of Local Isolate of Auky Island, Padaido District in Biak Numfor Papua as a Control of Anopheles Mosquito Larvae

This research aims to analyze the level of similarity and diversity among local isolates of B. thuringiensis Auky Island Padaido District in Biak Numfor Regency with NCBI gene bank base, the basis of which is to obtain B. thuringiensis isolates from jayapura local isolates that can act as controllers of Anopheles mosquito larvae. Several steps in the research are 16s gene amplification, PCR product purification, cloning using pTA2 vectors and transformation into competent E. coli Zymo 5α cells, confirmation with PCR colonies, recombinant plasmid isolation, sequencing analysis and phylogenetic tree construction. The isolates of ABNP8, ABNP9, ABNP11, ABNP12 and ABNP18 have been detected as local isolates from in Auky Island Padaido District in Biak Numfor Papua Regency that have great potential as bioinsecticides, and capable of controlling and killing Anopheles mosquito larvae. Of the five isolates, ABNP8 isolates had unique diversity and characteristics and were different from the four other isolates. Based on the similarity analysis in the MEGA7 program, the similarity rate reached 84%. Its diversity can be seen from the uniqueness of the sequence and its position in different branching dendrograms.

Use of anti-gSG6-P1 IgG as a serological biomarker to assess temporal exposure to Anopheles’ mosquito bites in Lower Moshi

Background Malaria prevalence in the highlands of Northern Tanzania is currently below 1% making this an elimination prone setting. As climate changes may facilitate increasing distribution of Anopheles mosquitoes in such settings, there is a need to monitor changes in risks of exposure to ensure that established control tools meet the required needs. This study explored the use of human antibodies against gambiae salivary gland protein 6 peptide 1 (gSG6-P1) as a biomarker of Anopheles exposure and assessed temporal exposure to mosquito bites in populations living in Lower Moshi, Northern Tanzania. Methods Three cross-sectional surveys were conducted in 2019: during the dry season in March, at the end of the rainy season in June and during the dry season in September. Blood samples were collected from enrolled participants and analysed for the presence of anti-gSG6-P1 IgG. Mosquitoes were sampled from 10% of the participants’ households, quantified and identified to species level. Possible associations between gSG6-P1 seroprevalence and participants’ characteristics were determined. Results The total number of Anopheles mosquitoes collected was highest during the rainy season (n = 1364) when compared to the two dry seasons (n = 360 and n = 1075, respectively). The gSG6-P1 seroprevalence increased from 18.8% during the dry season to 25.0% during the rainy season (χ2 = 2.66; p = 0.103) followed by a significant decline to 11.0% during the next dry season (χ2 = 12.56; p = 0.001). The largest number of mosquitoes were collected in one village (Oria), but the seroprevalence was significantly lower among the residents as compared to the rest of the villages (p = 0.039), explained by Oria having the highest number of participants owning and using bed nets. Both individual and household gSG6-P1 IgG levels had no correlation with numbers of Anopheles mosquitoes collected. Conclusion Anti-gSG6-P1 IgG is a potential tool in detecting and distinguishing temporal and spatial variations in exposure to Anopheles mosquito bites in settings of extremely low malaria transmission where entomological tools may be obsolete. However studies with larger sample size and extensive mosquito sampling are warranted to further explore the association between this serological marker and abundance of Anopheles mosquito.

The Rare, the Best: Spread of Antimalarial-Resistant Plasmodium falciparum Parasites by Anopheles Mosquito Vectors

Drug selection pressure in malaria patients is the cause of the emergence of resistant parasites. Resistance imposes a fitness cost for parasites in untreated infections, so withdrawal of the drug leads to the return of susceptible parasites.

Review of Anopheles Mosquito Species, Abundance, and Distribution in Ethiopia

Background. Malaria is a major mosquito-borne disease in Ethiopia, and it is one of the leading causes of morbidity and mortality. Plasmodium falciparum and P. vivax are the two malaria-causing parasitic species commonly known to cause human malaria in Ethiopia. To better manage and control vectors transmitting malaria parasites, the abundance, distribution, and updated annotated list of Anopheles species present in Ethiopia are very important. Methods. In order to compile a list of the species recorded in Ethiopia, 33 original research articles were collected. This work gives an updated list of Anopheles mosquito species in Ethiopia and their abundance, distribution, and composition. Results. According to this review, 110305 Anopheles mosquitoes were collected and 35 Anopheles species were recorded in different parts of Ethiopia. A. arabiensis was the most abundant when compared to other species, whereas A. maculipalpis and A. wilsonii were the least abundant species. The most abundant Anopheles species was recorded in central and the least abundant, from eastern Ethiopia. The second, third, and fourth abundant species were also collected from southern, northern, and western parts of Ethiopia.