Rift Valley fever (RVF) is an important neglected, emerging, mosquito-borne disease with severe negative impact on human and animal health. Mosquitoes in the Aedes genus have been considered as the reservoir, as well as vectors, since their transovarially infected eggs withstand desiccation and larvae hatch when in contact with water. However, different mosquito species serve as epizootic/epidemic vectors of RVF, creating a complex epidemiologic pattern in East Africa. The recent RVF outbreaks in Somalia (2006–2007), Kenya (2006–2007), Tanzania (2007), and Sudan (2007–2008) showed extension to districts, which were not involved before. These outbreaks also demonstrated the changing epidemiology of the disease from being originally associated with livestock, to a seemingly highly virulent form infecting humans and causing considerably high-fatality rates. The amount of rainfall is considered to be the main factor initiating RVF outbreaks. The interaction between rainfall and local environment, i.e., type of soil, livestock, and human determine the space-time clustering of RVF outbreaks. Contact with animals or their products was the most dominant risk factor to transfer the infection to humans. Uncontrolled movement of livestock during an outbreak is responsible for introducing RVF to new areas. For example, the virus that caused the Saudi Arabia outbreak in 2000 was found to be the same strain that caused the 1997–98 outbreaks in East Africa. A strategy that involves active surveillance with effective case management and diagnosis for humans and identifying target areas for animal vaccination, restriction on animal movements outside the affected areas, identifying breeding sites, and targeted intensive mosquito control programs has been shown to succeed in limiting the effect of RVF outbreak and curb the spread of the disease from the onset.

The attractiveness of oviposition site for malaria vector mosquitoes is dependent upon a number of physical and chemical factors. Many aspects of mosquito behavior, including host location and oviposition, are mediated by volatile semiochemicals. It is anticipated that selection of oviposition site by semio-chemicals in the form of attractants or stimulants can be used in oviposition traps to monitor or possibly in combination with insecticides to control gravid mosquito populations for mass trapping. So far, volatile compounds identified as oviposition attractants for mosquitoes include phenol, 4-methyl phenol, 4-ethyl phenol, indole, skatole, and p-cresol from hay infusions; 3-carene, -terpinene, -copaene, -cedrene, and d-cadinene released by copepods; alcohol and terpenoids including p-cresol from plants; ethyl acetate and hydrocarbon substances, probably released by filamentous algae; 3-methyl-1-butanol identified from bacteria. Research priorities should be directed at identifying more oviposition attractants to determine the properties of these semio-chemicals for possible use in designing control tools. This would aim at luring females to lethal traps or stimulants to increase their exposure to insecticide-impregnated substrates.

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Anopheles arabiensis Patton (Diptera: Culicidae) is considered the most efficient malaria vector in eastern Sudan. This study aims to characterize the breeding sites of An. arabiensis throughout the year in and around Kassala town, eastern Sudan. Diverse larval habitat types were visited and characterized based on the habitat type and chemical composition. Mosquito larvae were found in many diverse habitats. During the rainy season, rain pools and water bodies created by the seasonal Gash River serve as the main breeding sites. In the dry season, irrigation canals, seepage from water pipes, neglected wells, artificial containers, and man-made ditches serve as the main breeding sites. Breeding water showed a pH of 7.9 and a low concentration of the total dissolved salts. The results of this study may be considered in planning and implementing larval control programs in the area.

A comparative study of the reactions of two desert beetles, Adesmia antiqua Klug and Pimelia grandis Klug to temperature was made. A. antiqua preferred warmer temperatures between 20° and 40° C, P. grandis between 20° and 33°. The latter aggregated in a temperature zone of 28–34° whereas A. antiqua aggregated in a zone between 34–38°. Lethal temperatures of P. grandis and A. antiqua were 43° and 46° respectively for exposure of 24 hrs. Survival time at different temperatures and the effect of light on temperature reactions were also investigated. Zusammenfassung EINIGE TEMPERATUR‐REAKTIONEN ZWEIER WÜSTENKÄFER, ADESMIA ANTIQUA UND PIMELIA GRANDIS (TENEBRIONIDAE, COLEOPTERA) Die Reaktionen der beiden Wüsten‐Tenebrioniden Adesmia antiqua und Pimelia grandis auf verschiedene Temperaturen werden verglichen. Diese Verhaltensweisen wurden unter Benutzung einer Wahlkammer‐Apparatur geprüft, ähnlich der von Wigglesworth (1941) beschriebenen. Unterhalb 15° waren beide Arten träge und wenig aktiv. In alternativen Temperaturversuchen bevorzugte A. antiqua zwischen 20° und 40° wärmere Temperaturen, P. grandis dagegen solche zwischen 20° und 33°. In einem Temperaturgefälle sammelten sich die meisten P. grandis in einer Temperaturzone zwischen 28° und 40°, während A. antiqua sich in der Zone zwischen 34° bis 38° häuften. Beide Arten waren gegen niedere und hohe Temperaturen resistent. Sie vermochten länger als eine Woche bei 10° zu leben. Bei 60° überlebten sie mindestens 9 Minuten. Die Lage der oberen letalen Temperaturgrenze wurde für A. antiqua bei 46° ermittelt. Wenn Temperatur und Helligkeit zugleich geprüft wurden, bevorzugte P. grandis die dunklere Hälfte der Wahlkammer so lange, wie die Temperatur unter 39° blieb. Dagegen verhielt sich A. antiqua gegenüber Licht indifferent.