Search results for "Culex pipiens"

Vertical transmission of naturally occurring Bunyamwera and insect-specific flavivirus infections in mosquitoes from islands and mainland shores of L…

2018

Background Many arboviruses transmitted by mosquitoes have been implicated as causative agents of both human and animal illnesses in East Africa. Although epidemics of arboviral emerging infectious diseases have risen in frequency in recent years, the extent to which mosquitoes maintain pathogens in circulation during inter-epidemic periods is still poorly understood. This study aimed to investigate whether arboviruses may be maintained by vertical transmission via immature life stages of different mosquito vector species. Methodology We collected immature mosquitoes (egg, larva, pupa) on the shores and islands of Lake Baringo and Lake Victoria in western Kenya and reared them to adults. Mo…

Studies on the laboratory mating habits of the mosquito Culex pipiens

2009

SYNOPSIS The variation in copulatory activity in three strains of Culex pipiens is investigated and the results are discussed in relation to genetic control of mosquito populations.

Meiosis in translocation heterozygotes in the mosquito Culex pipiens.

1971

Adult Culex pipiens males irradiated with both X-rays and neutrons were crossed to untreated females and F1-egg rafts were checked for dominant lethality. F1-progenies were outcrossed with normal individuals in order to obtain lines with inherited semisterility. From a total of 120 lines that showed a certain amount of sterility 12 lines were studied cytologically. 10 lines showed reciprocal chromosome exchanges.—At late pachytene and diplotene cross configurations with large asynaptic regions at the center of the cross are obligatory. Bivalents, chains of three, chains of four, and ring configurations are present at metaphase and anaphase I. The different frequencies of the occurrence of s…

Crossing over in Culex pipiens fatigans translocation heterozygotes

1981

A Red Eye Colour Mutation in Culex pipiens after X-irradiation

1963

FOUR 1–2-day-old males of Culex pipiens were irradiated with a dose of 4,000 r. The mutant ‘red eye’ (r) was isolated from F3 cultures of two of the irradiated males (♂ II and ♂ IV). From male II, there were three red-eyed females which arose out of a single F2 brother–sister mating; from male IV, 80 red-eyed females and one red-eyed male from 14 F2 brother–sister matings. According to the experimental procedure, this means that at least one sperm from male II and at least fourteen sperms from male IV carried the mutation r. Thus, the same mutation was recovered in parallel from two irradiated males. The clustered appearance of the mutation in male IV was presumably caused by the occurrence…

Development of cytoplasmically incompatible and integrated (translocated incompatible) strains ofCulex pipiens fatigans for use in genetic control

1976

Crosses were made between strains of the Culex pipiens complex to select and develop strains with suitable cytoplasmic incompatibility properties for use in field experiments in genetic control of Culex pipiens fatigans near Delhi, India.

Effect of an Insect Growth Regulator (Halofenozide) on the Cuticular Hydrocarbons ofCulex pipiensLarvae

2013

The cuticular hydrocarbons of the fourth-instar larvae of Culex pipiens aged one and six days were analysed by gas chromatography and gas chromatography-mass spectrometry. The effect of an insect growth regulator (halofenozide = RH-0345) on the cuticular hydrocarbons was evaluated using newly moulted fourth-instar larvae of C. pipiens, at the lethal concentrations (LC50 = 12.58 and LC90 = 28.58 µ/l). A previous study revealed that RH-0345 is toxic to larvae of C. pipiens by induction of precocious larval moulting. Several cuticular hydrocarbons (CHCs) were identified and many of the other compounds remained unknown. Our data show that the CHC classes consisted of n-alkanes (C23-C29) and dif…

Composition and Genetic Diversity of Mosquitoes (Diptera: Culicidae) on Islands and Mainland Shores of Kenya's Lakes Victoria and Baringo.

2016

The Lake Baringo and Lake Victoria regions of Kenya are associated with high seroprevalence of mosquito-transmitted arboviruses. However, molecular identification of potential mosquito vector species, including morphologically identified ones, remains scarce. To estimate the diversity, abundance, and distribution of mosquito vectors on the mainland shores and adjacent inhabited islands in these regions, we collected and morphologically identified adult and immature mosquitoes and obtained the corresponding sequence variation at cytochrome c oxidase 1 (COI) and internal transcribed spacer region 2 (ITS2) gene regions. A total of 63 species (including five subspecies) were collected from both…

Inherited semisterility for control of harmful insects. II. Degree of sterility and types of translocations in the mosquito Culex pipiens L.

1971

Fur die Anwendung von Semisterilitat infolge von Translokationen zur Bekampfung schadlicher Insekten ist der Grad der Semisterilitat und die Art der zugrundeliegenden Translokation von Bedeutung. Von den bisher untersuchten 124 Translokationen hatten 101 einen Sterilitatsgrad zwischen 10 und 50%, 23 uber 50 bis zu 85%. Mit dem mannlichen Geschlechtsfaktor M gekoppelte Translokationen sind zur Zeit die fur die Praxis am nutzlichsten. Sie treten nicht so haufig auf als erwartet, machen aber doch rund 1/4 aller getesteten Translokationen aus. Es werden Grunde angefuhrt, weshalb M-gekoppelte Translokationen nutzlicher sind.

Eradication of Culex pipiens fatigans through Cytoplasmic Incompatibility

1967

Culex pipiens fatigans is the chief vector of filariasis in south-east Asia. Urbanization has often caused the numbers of this mosquito—and with it the danger of filariasis infection—to increase alarmingly1. The natural vigour, tolerance and fast development of resistance to insecticides of this mosquito necessitate the development of other control methods, and cytoplasmic incompatibility2 seems to be an ideal means.