Data-driven networking of global transcriptomics and male sexual development in the main malaria vector, Anopheles funestus.

Deaths from malaria remain staggering despite global support that drives research into new territories. One major gap is our understanding of the sexual biological aspects of the male mosquito, which maintain the vector population solidity. Although Anopheles funestus s.s. is an extremely efficient African vector, little is known about the network between its sexual physiology and gene expression. The Culicidae male's sexual maturity involves a suite of physiological changes, such as genitalia rotation that is necessary for successful mating to occur. We show that mating success is guided by genes and physiological plasticity. Transcriptome analysis between newly emerged males (immature) versus males with rotating genitalia (maturing) provides insight into possible molecular mechanisms regulating male sexual behaviour. Putative transcripts that were associated with male sexual maturation were identified and validated. The discovery of the functions of these transcripts could lead to identifying potential targets for innovative vector control interventions, and mosquito population suppression.

Ecology of malaria vector Anopheles culicifacies in a malarious area of Sistan va Baluchestan province, south-east Islamic Republic of Iran.

A study was done of the bionomics, insecticide susceptibility and irritability status of Anopheles culicifacies in Sistan va Baluchestan province. Sampling was performed to determine the following parameters: species identification, seasonal activity, adult and larval susceptibility tests, irritability tests, anthropophily index and sporozoite rate. An. culicfacies adults were susceptible to all tested pyrethroid insecticides. An. culicfacies started to appear indoors in late May, showing 2 peaks in June and September. Fenitrothion, cyfluthrin and permethrin had the least irritancy effect and DDT the highest. Only 2/860 females tested were infected with Plasmodium spp. (sporozoite rate: 0.25%). ELISA testing of 250 blood meals derived from night-biting collections of female mosquitoes from humans and cows revealed that only 12.5% were human-fed.

Ecology of malaria vector Anopheles culicifacies in a malarious area of Sistan va Baluchestan province, south-east Islamic Republic of Iran

A study was done of the bionomics, insecticide susceptibility and irritability status of Anopheles culicifacies in Sistan va Baluchestan province. Sampling was performed to determine the following parameters: species identification, seasonal activity, adult and larval susceptibility tests, irritability tests, anthropophily index and sporozoite rate. An. culicifacies adults were susceptible to all tested pyrethroid insecticides. An. culicifacies started to appear indoors in late May, showing 2 peaks in June and September. Fenitrothion, cyfluthrin and permethrin had the least irritancy effect and DDT the highest. Only 2/860 females tested were infected with Plasmodium spp. [sporozoite rate: 0.25%]. EL1SA testing of 250 blood meals derived from night-biting collections of female mosquitoes from humans and cows revealed that only 12.5% were human-fed

Application of predictive degree day model for field development of sandfly vectors of visceral leishmaniasis in northwest of Iran.

BACKGROUND & OBJECTIVES: Temperature plays a significant role in insect's development where a rise in temperature, accelerates the insect's metabolic rates, increases egg production and makes blood feeding more frequent. It also shortens the time period required for the development of pathogens within insects. Visceral leishmaniasis (VL) is one of the most important vector-borne diseases transmitted by different sandfly species. In this study, a phenological model was used to estimate the number of generations, peak activity and temporal variability of sandflies in the main VL foci in northwest Iran. METHODS: Development requirements of different life stages of a Phlebotomus papatasi laboratory colony were measured and were subjected to the formula for calculation of accumulated degree day (ADD) for field sandflies using the online soft (UC IPM), using horizontal cut-off method and single triangle model. Sandflies population dynamics was monitored in the field during the seasonal activity in the region and its association with the ADD was tested using SAS software. RESULTS: Populations of sandflies accommodated well with the amount of accumulated degree days (ADD) in the region. During the seasonal activity, a total of 639 ADD were produced which was enough to support one complete life cycle and growth of the next generation up to late larval instar. Larvae of the second generation hibernate through winter and the first adult population appears in the mid to late June of the next year when they receive at least 182 ADD from the beginning of the spring. The highest population density of sandflies was observed in early August, followed by a rapid decrease in early September, with the adult population disappearing completely in late September. This is the first degree day model related to sandflies in the most important VL foci of Iran. INTERPRETATION & CONCLUSION: Further studies in various regions with variable climate are recommended in order to better estimate and understand the development time, population dynamics and activities of the vectors which in turn could be used in proper implementation of effective vector control programmes.

Morphological method for sexing anopheline larvae.

BACKGROUND & OBJECTIVES: Most of autocidal control of malaria vectors relies on the rearing and release of large numbers of sterile male into a wild population and it would be crucial to separate the males from females before release. This could result in enormous economic benefits in the mass rearing and raise the efficiency of the field operations. The development of genetic sexing of mosquitoes, enabling the release of males only, but impairing the overall fitness of the released insect has been considered greatly. Here we report on a morphological sexing method for the preferential diagnosis and separation of males in late III and IV instar larvae for the mosquitoes Anopheles stephensi Liston and An. culicifacies s.l. (Diptera: Culicidae), the principal vectors of human malaria in Asia and Indian subcontinent. METHODS: Male mosquitoes are identified by their tube like organ at the 9th abdomen segment which originates from segment parallel to the spiracles. Length and width of this organ is measured as 66.66 +/- 9.5 and 14.3 +/- 1.5 microm respectively. The whole length of the organ is 201.63 +/- 23.4 microm. Two fried eggs in the anterior portion of the segment are apparent in males. The length of tube in female is shorter than the male (almost half of the length--37.95 +/- 4.0 microm), its width is slightly stout and wider than the male (16.72 +/- 1.4 microm). Two fried eggs in the anterior portion of the segment are absent. After separation of live male larvae by those characteristics, they were transferred into the trays and emerged adults were identified to ascertain correct identification of sex. RESULTS: All the larvae with male organs developed into male adults with hairy antennae and club shaped palpi, whereas all the female larvae developed into adult females. INTERPRETATION & CONCLUSION: The sex separation at the larval stage will provide a clue for embryonic origin of sex organs, insecticide selection at the larval stage, sex related genes, male sterility and other measures.