Species Variety of the Calf and Human-Attracted Mosquitoes in Southwest Iran

Background: Any mosquito control methods requires precise information about population dynamics, variety, biology and mosquito habitat. This research assessed Culicid mosquitoes' attraction to a human host and a calf to better understand their behavior. Methods: Adult mosquitoes were sampled in 22 weeks in southwestern Iran's Nur Ali Village from May to October 2015. The mosquitoes were drawn to the person and calf as bait, while the unbaited trap was also used. A substantial statistical difference between attracted mosquitoes to the hosts was determined in the T-test. Results: Within 22 weeks, 29821 mosquitoes were captured. Only 9% were collected from the human baited net trap, 89.1% from the calf baited net trap, and 1.9% from the unbaited net trap. The number of collected female mosquitoes was statistically significantly higher using the calf baited net trap of the total mosquitoes, 916 were randomly identified at the species level by local identification keys. Of these, 63 were Anopheles stephensi (human: 16%, calf: 75% and unbaited: 9%), 83 An. pulcherrimus (human: 27%, calf: 60% and unbaited: 13%), 118 Aedes caspius (human: 24%, calf: 69% and unbaited: 7%), 493 Culex tritaeniorhynchus (human: 52%, calf: 37% and unbaited: 11%), 153 Cx. quin­quefasciatus (human: 44%, calf: 47% and unbaited: 9%), and 6 Cx. theileri (human: 33%, calf: 50% and unbaited: 17%). Conclusion: The obtained results here provide useful insights into the mosquito population and the possibil­ity of using this information as an essential part of integrated vector management regarding the reemergence of malaria or other mosquito-borne.

Potential Mosquito Vectors of Dirofilaria immitis and Dirofilaira repens (Spirurida: Onchocercidae) in Aras Valley, Turkey

Dirofilaria immitis (Leidy, 1856) and Dirofilaria repens (Railliet & Henry, 1911) are mosquito-borne filarial nematodes that primarily affect dogs, causing heartworm disease and subcutaneous dirofilariosis. The canine heartworm is reported in different provinces in Turkey. However, studies about the transmitting mosquito species are limited. Hence, this study aimed to investigate potential vectors of D. immitis and D. repens in Aras Valley, Turkey. In total, 17,995 female mosquitoes were collected from eight villages during three mosquito seasons (2012–2014) in Aras Valley, located in north-eastern Turkey. A total of 1,054 DNA pools (527 abdomen and 527 head-thorax) were tested with Dirofilaria primers by multiplex-polymerase chain reaction (PCR). Aedes caspius was the most abundant species in collection sites with 90%; this was followed by Culex theileri Theobald, 1903 (Diptera: Culicidae) (7.31%), Anopheles maculipennis Meigen 1818 (Diptera: Culicidae) (1.28%), Culex pipiens Linnaeus, 1758 (Diptera: Culicidae) (0.43%), (Anopheles) hyrcanus (Pallas, 1771) (Diptera: Culicidae) (0.37%), Aedes vexans (Meigen, 1830) (Diptera: Culicidae) (0.25%), and Culiseta annulata Schrank, 1776 (Diptera:Culicidae) (0.02%). Dirofilaria immitis and D. repens were detected in mosquito pools from five villages. The total Dirofilaria spp. estimated infection rate was 1.33%. The highest estimated infection rate was found in Ae. vexans (6.66%) and the lowest was in Ae. caspius (1.26%). The results show that An. maculipennis sl, Ae. caspius, Ae. vexans, Cx. theileri and Cx. pipiens are potential vectors of D. immitis and D. repens with DNA in head-thorax pools; An. hyrcanus is also a likely vector, but Dirofilaria DNA was found only in abdomen pools for the study area. This study revealed new potential vector species for D. immitis. Mosquitoes with natural infections of D. repens were reported for the first time in Turkey.

Evaluation of Susceptibility of Aedes caspius (Diptera: Culicidae) to Insecticides in a potent arboviral-prone Area, Southern Iran

Background: Southern part of the country is a high risk for mosquito transmitted Arboviruses. This study was carried out to determine the base line susceptibility of the Aedini mosquitoes to the WHO-recommended insecticide. Methods: Larval collection was carried out by dipping method and adult collection occurred by suction tube from January to December 2017. The adult susceptibility test was assessed to Bendiocarb 0.1%, DDT 4%, Deltamethrin 0.05%, Lambda-cyhalothrin 0.05%, Malathion 5% and, Permethrin 0.75% at different interval times as well as at discriminative dose recommended by WHO. The larval susceptibility test was occurred using Temephos and Bacillus thuringiensis serotype H-14, at different concentrations. The LT50, LT90 and LC50, LC90 values were calculated for plotting the regression line using Microsoft office Excel software ver. 2007. Results: Aedes caspius was quite resistant to DDT, Malathion, Bendiocarb and showed susceptible or tolerant to other insecticides.The LT50 and LT90 values to DDT in this species were 157.896, and 301.006 minutes, respectively. The LC50 and LC90 values of Ae. caspius to Temephos were 0.000068, and 0.000130ppm, the figures for B. thuringiensis was 111.62 and 210.2ppm, respectively. Conclusion: A routine and continuous study for monitoring and evaluation of different species of Aedes to insectides is recommend at different parts of country for decision making.

Pathomorphological changes in the larvae cells of blood-suckıng mosquitoes (Aedes caspius Pallas, 1771) affected by parasitizing microsporidium Amblyospora (=Thelohania) opacita Kudo, 1922

Microsporidia are highly specialized obligate intracellular parasites. They affect various tissues of most animal groups. In Azerbaijan, 29 species and forms of microsporidia were recorded. Of these, 10 species (Amblyospora minuta, Pleistophora obesa, Thelohania opacita, Th. opacita caspius, Th. vexans, Stempellia captshagaica, St. magna, Nosema caspius, Nosema sp., Culicosporella sp.) were found in four species of blood-sucking mosquitos (Culix pipiens pipiens, Aedes vexans, A. caspius, Culex theileri). The collected larvae were identified using the key of Gutsevich et al. (1970). In the laboratory, the mosquito larvae were examined against a dark background under the microscope MBS-9 to distinguish individuals infected with microsporidia. Smears were stained with azure-eosin. Histological slices were prepared according to the Volkova and Yeletskiy method (1971); pathological changes in host tissues were identified using the electron microscope JEM 1400. In the course of our research conducted in 2017–2018 on the Absheron peninsula (Azerbaijan), the life stages of the microsporidium Amblyospora (=Thelohania) opacita Kudo, 1922 were found in the larvae of Aedes caspius Pallas, 1771. Examination of the infected host cell ultrastructure revealed the following changes: rough endoplasmic reticulum and mitochondria concentration around the parasite, an increase of cytoplasm volume, initiation of cell hypertrophy, disappearance of fat, protein granules and rough endoplasmic reticulum at later development stages, a decrease in the number of ribosomes in the cytoplasm and their simultaneous increase around the periphery of the nucleus, mitochondria degradation. These changes cause a delay in the larva development. Microsporidiosis affects the whole mosquito life cycle. The effect of microsporidia on the host organism manifests itself in the delayed larvae development and, in some cases, their early death. First of all, the lipid granules disappear supposedly because of the intensification of the host's aerobic metabolism to compensate for the energy loss caused by the developing parasites.

A Survey of Aedes (Diptera: Culicidae) Mosquitoes in Tunisia and the Potential Role of Aedes detritus and Aedes caspius in the Transmission of Zika Virus

The present study aimed to update the list of Aedes mosquito species occurring in Tunisia and to test the vector competence of Aedes (Ochlerotatus) caspius (Pallas) and Ae. (Ochlerotatus) detritus (Haliday), the locally most abundant and widespread species, to transmit Zika virus (ZIKV). In 2017–2018, mosquito larvae were collected from 39 different larval habitats in seven bioclimatic zones of Tunisia. The salinity and pH of each breeding site were measured. The survey revealed the presence of 10 Aedes species in Tunisia: Ae. (Stegomyia) albopictus (Skuse), Ae. (Ochlerotatus) berlandi (Séguy), Ae. caspius, Ae. detritus, Ae. (Finlaya) echinus (Edwards), Ae. (Finlaya) geniculatus (Olivier), Ae. (Acartomyia) mariae (Sergent and Sergent), Ae. (Ochlerotatus) pulcritarsis (Rondani), Ae. (Aedimorphus) vexans (Meigen), and Ae. (Fredwardsius) vittatus (Bigot). Of these 10 species, Ae. caspius and Ae. detritus were the most abundant in Tunisia. Aedes detritus and Ae. caspius larvae were reared until the imago stage under insectary conditions to test autogeny. The study showed that Ae. detritus is autogenous and stenogamous and Ae. caspius, anautogenous and eurygamous. Finally, the collected strains of these two species were experimentally infected with the Asian genotype of ZIKV, originally isolated from a patient in April 2014 in New Caledonia, to test their vector competence. Neither of these species was able to transmit ZIKV at 7 and 14 d postexposure. Further investigations are needed to test the competence of other Tunisian mosquito species that may be associated with ZIKV transmission.

Biodiversity of Mosquitoes (Diptera: Culicidae) with Emphasis on Potential Arbovirus Vectors in East Azerbaijan Province, Northwestern Iran

Background: The abundance, diversity, distribution and ecology of mosquitoes (Diptera: Culicidae), especially ar­bovirus vectors are important indices for arthropod-borne diseases control. Methods: Larvae and adult mosquitoes were collected using the standard methods from different habitats in nine localities of three counties in the East Azerbaijan Province, Northwestern Iran during June to October 2017. In addi­tion, species richness (R), Simpson’s diversity index (D), Shannon–Wiener index (H̕) and evenness (E) as measures of diversity, were calculated. Results: Overall, 1401 mosquito specimens including 1015 adults and 386 larvae were collected in the study area. The properties of geographical larval habitats were recorded. Four genera along with 10 species were collected and identified, including Anopheles hyrcanus, An. maculipennis s.l., An. superpictus s.l., Aedes caspius, Ae. vexans, Cu­lex pipiens, Cx. theileri, Cx. perexiguus, Culiseta longiareolata and Cs. subochrea. Among the three counties, Ahar region presented the highest species richness (R: 1.5) and diversity values (D: 0.79, H’: 1.74, E: 0.73). Conclusions: This study provides important information on the diversity, distribution and ecology of ten mosquito species in the region. This information leads to a better understanding of mosquito population dynamics in relation to vector control measures.