THE DENSITY OF ANOPHELES ARABIENSIS (DIPTERA: CULICIDAE) IN CORRELATION TO MALARIA CASES AND SOME ENVIRONMENTAL FACTORS IN THREE VILLAGES AROUND WAD MEDANI TOWN

This work aimed at studying the population density of Anopheles arabiensis and the incidence of malaria, during July–December 2001 and 2002. The study was conducted in three villages, namely Kereba, Barakat and Hantoub. The mean temperature and amount of rain fall were also recorded during this study. The results showed that the species of Anopheles arabiensis (Larvae and Adults) were recorded in all villages. The numbers recorded for this vector species were higher during September, in Kereba and Hantoub villages and during August in Barakat village than during the other months, during 2001. In 2002, the means recorded for this species were higher during September and October in Kereba and during August and September in Barakat and Hantoub than during other months. The species were not recorded during November and December 2002 in all villages. The overall mean number of the vector recorded in all villages was higher in 2001 than in 2002. The number of malaria cases recorded in all villages was highly correlated with the number of vectors recorded and with the environmental factors (means temperature and the amount of rain fall), during 2001, the amount of rainfall was high and this may have led to the increase of the breeding sites, and hence, the malaria cases recorded. During both years the numbers of vectors and of the resulting malaria cases were higher in Kereba and Barakat villages, than in Hantoub village. &nbsp

Effect of Aqueous Extract of Cathedral Cactus (Euphorbia trigona Mill) on Larvae of Anopheles arabiensis (Diptera: Culicidae)

Abstract: Mosquitoes are considered as vector of malaria disease and some other endemic diseases in the world. There are some methods already been used for controlling mosquito; of which is using natural products. This study was conducted at Laboratories of Faculty of Engineering and Technology, University of Gezira, to evaluate the effect of cortex, spine and pith parts of cactus (Euphorbia trigona) on Anopheles mosquito larvae. The plant parts were collected from Wad Medani City, whereas, the mosquito larvae were collected from the breeding sites at Tayba village, Gezira State, Sudan. The plant parts (cortex, spines and pith) were shade dried away from the direct sunlight, grounded and then kept separately in small plastic sacks. From each plant part, a concentration of 1200 mg/L was used. The standards of WHO for testing toxicity of the toxic compound against mosquito larvae was followed. The mortality in Anopheles larvae were 48%, 37% and 62%, respectively, for trigona cortex, spine and pith. The results also showed that, the three used parts have a varied great impact on the survived larvae (morphological changes of skin color was in 82%, disconnecting of digestive tract was in 48%, and separation of some body parts was in 32%, after 48 hours of applying it). The study recommends adding these cactus parts as potential natural products for Anopheles larval control, and also running more sensitive tests to measure the environmental impact of these products, especially on human and on the aquatic faun

Population Density, Developmental Period and Fecundity of Anopheles Mosquito (Diptera: Culicidae) in the Gezira State, Sudan

In the Gezira State, insecticides were used for many years for controlling mosquitoes and other agricultural pests. The objective of this work was to study the population density, the developmental periods the reproductive periods and the fecundity of Anopheles mosquitoes in the Gezira State, Sudan. The study was conducted in three sites; Elmanagel, Elhosh and Wad Medani.Ten of one-day old or less of the cultured adult males and females of A. pharoensis wewe transferred separately to cage. The female pre-oviposition period, daily number of eggs deposited, the oviposition period, the post oviposition period, the adult longevity and the average number of eggs per female were recorded. The results revealed that, the number of A.arabiensis larvae collected from  the three sites was higher than that of A. pharoensis and A. funestus during the two seasons (2009 and 2010). The number of A. funestus adults collected at Wad Medani site during the two seasons was lowest than that collected from El Managel and El Hosh. The incubation period of the eggs, was relatively similar in all Anopheles species, as same as the larval period. The pupal period was relatively longer in A. funestus (2.4 days) and A. pharoensis (2.2 days) than in A.arabiensis (2 days). Adult A. pharoensis lived relatively longer (21 days) than A arabiensis and A. funestus (20 days). The total life cycle was relatively longer (32 days) in A. pharoensis than in A. arabiensis and A. funestus (30 days for each). Females of all species of Anopheles mosquito oviposited after one day from their emergence from the pupae and took also one day before they oviposit again. The oviposition period was significantly longer in A. arabiensis (3.3 days) than in A. pharoensis (2.5 days) and A. funestus (1.8 days). The oviposition rate was significantly higher in A. arabiensis (191) than in  A. pharoensis (150) and A. funestus (79). The fecundity of A. arabiensis (624 eggs/female) was significantly greater than that of A. pharoensis (391 eggs/female) and A. funestus (141 eggs/female). Such study should be run periodically for all sites in the Gezira State and neighboring States. &nbsp