White mango scale (Aulacaspis tubercularis Newstead; Hemiptera: Diaspididae) is a major insect pest of mango production threatening production and marketing of mango in Ethiopia. The present study was conducted to determine the current status of the white mango scale (WMS) and to identify the factors contributing to the damage level of the pest. A cross-sectional survey was conducted in ten selected kebeles in Assosa district, western Ethiopia, during 2021/2022 cropping season. Data on infestation level and WMS life-stage abundance were recorded from fifty randomly selected mango orchards. Data on the prevalence of WMS and factors influencing the distribution and damage levels of white mango scale infestations were analyzed using SAS and SPSS software respectively. The results of this study indicate that WMS infestation was prevalent in all assessed mango growing areas of the district. There was a significant (p < 0.05) difference between kebeles and mango orchards in infestation level and WMS life-stage population densities. Poor cultivation, crop husbandry practices, and pest management strategies have been identified as the major contributing factors for high pest infestation. The study indicates that WMS infestations are increasing in the study area; thus, there has to be strong efforts towards the implementation of safe and effective management strategies.

Malaria is the leading causes of morbidity and mortality in Ethiopia and 75% of the land of Ethiopia is malarious. Anthropogenic activities, such as mining and water resource projects (dams and irrigation) are among the major factors determining malaria epidemiology. The aim of this study was to disclose the seasonality, abundance, and biting behavior of Anopheles mosquitoes in the gold mining settings of western Ethiopia. A longitudinal entomological survey was conducted in traditional gold mining vicinities of Menge district, Western Ethiopia from January to December, 2021. Adult Anopheles mosquitoes were collected using Centers for Disease Control and Prevention (CDC) light trap and Pyrethrum Spray Catch (PSC) followed by identification and analysis. A total of 1882 Anopheles mosquitoes belonging to six species (An. gambiae s.l., An. funestus, An. pharoensis, An. coustani, An. zeimanni and An. squamosus) were collected during the study period. The highest number (59.29%; n = 1116 of Anopheles mosquitoes were collected from Shegole gold mining site compared to Kudyu site (41.23%; n = 766). Similarly, the density of An. gambiae s.l was high in Shegole (village with community exclusively depending on gold resource) (203, 60.23%). Outdoor host seeking mosquito density was higher (1111, 59%) than indoor host seeking mosquito density (771, 41%) (P < 0.05). The highest number of Anopheles mosquitoes was recorded in August with a mean density of 3.86 ± 1.548 followed by September (3.19 ± 1.499) while the lowest mosquito density was recorded in February with mean density of 3.00 ± 0.000. In conclusion, Anopheles mosquito abundance was seasonally lopsided among sites with varied gold mining practices in western Ethiopia. Anopheles gambiae s.l. was the predominant malaria vector with disparity in its spatio-temporal distribution.

Malaria is a widespread vector-borne disease in the tropics and subtropics causing nearly half a million deaths every year. Malaria vector control intervention mainly rely on the control of adults using Indoor residual sprayings (IRS) and long lasting insecticidal nets (LLINs). The purpose of this study was to assess the species composition of Anopheles mosquitoes and determine the environmental and physicochemical parameters of their breeding habitats in Bambasi district, Benshangul Gumuz regional state, northwestern Ethiopia. Three major Anopheles breeding habitats were identified in three Kebeles namely; drainage ditch (Keshmando), swamp (Amba 46), and stagnant water (Amba 47). Anopheles mosquito larvae were sampled twice a month from September 2020 to November 2020. A total of 2185 Anopheles mosquito larvae were collected. Of those collected larvae three Anopheles species (Anopheles gambiae s.l. An. funestus and An. coustani complex) were identified. Anopheles gambiae s.l was the most abundant whereas An. funestus and An. coustani were the least in all the study kebeles. Of the three kebeles, Amba 47 was found the most productive for Anopheles followed by Amba 46 and Keshmando. The highest mean density of larvae per dip was sampled in September in all the study sites. The three sampling sites varied in physicochemical characteristics. The findings of this study showed that dissolved oxygen (DO) was highest (7.07 $$\pm$$ 0.55 mg/L) in the swamps and lowest (0.32 $$\pm$$ 0.04 mg/L) in the drainage ditches. Conductivity across different habitats showed wide variations. There were slight variations in temperature between different habitats. Higher total dissolved solids (TDS) 12.19 $$\pm$$ 0.26 mg/L was recorded from the drainage ditches; whereas TDS 9.49 $$\pm$$ 1.62 mg/L was recorded from the swamp. Salinity in the drainage ditches and stagnant water was 5.54 $$\pm$$ 1.00PSU and 3.30 $$\pm$$ 0.97 PSU respectively. There were negative strong correlation between the larval density with temperature and EC but positive correlation between larval density with salinity. However, there was no significant correlation between Anopheles larval density with TDS and DO. In conclusion this study suggested that environmental and physicochemical factors could play an important role in the development of mosquito larvae. Therefore, characterizing mosquito larval habitats is important for targeted control of malaria vectors in Ethiopia.

The highest malaria transmission risk as stratified by annual parasite incidence, appears largely in Benishangul Gumuz region, the lowland and midlands of the western border with Sudan and South Sudan. The effectiveness of malaria vector control strategy depends on knowledge of factors that determine vector density and distribution, affecting adult Anopheles vector population dynamics and malaria transmission. This study aimed to investigate the spatial-temporal distribution and species composition of Anopheles mosquitos in western Ethiopia. The study was conducted in three districts of Assosa Zone (Assosa, Homosha and Bambasi), Benishangul Gumuz regional state. Adult and larva of Anopheles mosquitoes were collected using standard techniques after the long rainy season (October 2020-December 2020) and Dry season (January to February 2021). After collection, the data were analyzed using SPSS software. A total of 2063 Anopheles mosquitoes (1745 larvae and 318 adults) were collected during the study period and categorized into five Anopheles species (An. gambiae, An. funestus, An. coustani, An. ziemanni, and An. squamosus). Among all species An. gambiae s.l. (1548, 88.7%) was the predominant species while An. squamous (14, 0.8%) was the least dominant. From the three districts, the highest Anopheles mosquito specimens were collected from Bambasi (917, 52.6% larval and 126, 39.6% adult). And out of all collection months, the highest number of larvae and adult mosquitoes was collected during October. Among larval breeding habitats, pond was highly productive for Anopheles mosquitoes. Anopheles mosquitoes prefer to breed in all breeding sites, particularly temporary and sunlit habitats. Anopheles gambiae s.l. predominantly occurs during all seasons in its immature and mature stages, suggesting that malaria is a health problem in the area.

Background The emergence and spread of resistant strains of malaria vectors to chemical insecticides are becoming major problems for malaria vector management. Natural plant products have a vital role to play in the current challenge of malaria control. The current study was conducted to evaluate insecticidal effect of ethnobotanical plant extracts against the primary malaria vector, Anopheles arabiensis in northwestern Ethiopia. Methods Primarily, ethnobotanical plants used for Anopheles mosquito control were surveyed in Dangur district, northwestern Ethiopia. Insecticide-susceptible strains of Anopheles arabiensis mosquito were reared in the insectary of the Tropical and Infectious Diseases Research Centre, Assosa University. After surveying plants used for mosquito control in local people, four frequently used plants were identified for extraction. The larvicidal and adulticidal potential of frequently used plant extracts against susceptible strains of the laboratory colony were evaluated. Results A total of 15 plants were identified as ethnobotanical plants that help local people with mosquito control. Azadirachta indica, Ocimum lamiifolium, Ocimum americanum, Moringa olifeira leaf, and Moringa olifeira seed species of local plants were found to be frequently used to kill and/or repel mosquitoes in the study district. All the plant extracts were found to have potential larvicidal activity against fourth instar larvae of An. arabiensis and only ethanol and methanol extract of Azadirachta indica and Ocimum lamiifolium were found to have potential adulticidal effect against adult of An. arabiensis . The highest larvicidal activity was observed in ethanol extract of Azadirachta indica with 95% larval mortality and lowest Lethal Concentration 50 (LC 50) of 40.73parts per million (ppm) and LC90 of 186.66 ppm. The highest adulticidal activity was observed in methanol extract of Azadirachta indica with 75% adult mortality at 300 ppm and lowest LC50 of 106.65 ppm and LC90 of 1,293 ppm. The lowest larvicidal and adulticidal activity was observed in methanol extracts of Ocimum lamiifolium with 63.35% larval mortality and leaf extract of Moringa olifeira with 50% adult mortality at 300 ppm, respectively. Conclusion Ethanol extract of Azadirachta indica exerted a remarkable larvicidal effect against An. arabiensis and thus it can be used for botanical mosquito insecticide development. Since the current finding is based on susceptible strain of An. arabiensis , further work on wild mosquitoes is recommended.

Background Anopheles stephensi , an invasive malaria vector, was first detected in Africa nearly 10 years ago. After the initial finding in Djibouti, it has subsequently been found in Ethiopia, Sudan and Somalia. To better inform policies and vector control decisions, it is important to understand the distribution, bionomics, insecticide susceptibility, and transmission potential of An. stephensi . These aspects were studied as part of routine entomological monitoring in Ethiopia between 2018 and 2020. Methods Adult mosquitoes were collected using human landing collections, pyrethrum spray catches, CDC light traps, animal-baited tent traps, resting boxes, and manual aspiration from animal shelters. Larvae were collected using hand-held dippers. The source of blood in blood-fed mosquitoes and the presence of sporozoites was assessed through enzyme-linked immunosorbent assays (ELISA). Insecticide susceptibility was assessed for pyrethroids, organophosphates and carbamates. Results Adult An. stephensi were collected with aspiration, black resting boxes, and animal-baited traps collecting the highest numbers of mosquitoes. Although sampling efforts were geographically widespread, An. stephensi larvae were collected in urban and rural sites in eastern Ethiopia, but An. stephensi larvae were not found in western Ethiopian sites. Blood-meal analysis revealed a high proportion of blood meals that were taken from goats, and only a small proportion from humans. Plasmodium vivax was detected in wild-collected An. stephensi . High levels of insecticide resistance were detected to pyrethroids, carbamates and organophosphates. Pre-exposure to piperonyl butoxide increased susceptibility to pyrethroids. Larvae were found to be susceptible to temephos. Conclusions Understanding the bionomics, insecticide susceptibility and distribution of An. stephensi will improve the quality of a national response in Ethiopia and provide additional information on populations of this invasive species in Africa. Further work is needed to understand the role that An. stephensi will have in Plasmodium transmission and malaria case incidence. While additional data are being collected, national programmes can use the available data to formulate and operationalize national strategies against the threat of An. stephensi .

Traditional medicinal plants have played a major role in the enhancement of health care in developing countries around the world. Ethiopia has been practicing traditional botanical medicine for the curing of human biological, mental or physical disorders. Ethno botanical study was carried out to survey medicinal plants and their uses for malaria control in Assosa district. Information was collected from 150 medicinal plants users and traditional medicine healers via interviewer-administered questionnaires. The informants were selected randomly from four different villages of Assosa district, Southwestern Ethiopia. A total of 11 species of ethno botanical medicinal plants used for malaria control were identified. Of eleven ethno botanical plants, Allium sativum and Echinops kebericho were majorly used for malaria treatment and vector prevention in Assosa district. Leafs were the mostly used part of the plant and most of the medicinal plants were used for treating infections. The indigenous knowledge and practice of traditional medicinal plants in the study area were at risk of getting lost. The communities in the current study area practiced traditional ethno botanical medicine for malaria therapy and disease prevention. The indigenous practices contributed to the sustained use, management and protection of medicinal plants and multiple-use of ethno botany/indigenous trees. The current study suggests that similar studies in areas not previously covered should be carried out in order to get a full picture of the country's medicinal plants potential in the future.