The study of annual presence to family Dytiscidae is started between November 2015 until the end of October 2016 in the districts of the city and Qurnah and the center of the city of Basra and Shatt al-Arab and Abi Fertile, and the results recorded five types are Cybister tripunctatus, Hydaticus ponticus, Hydrovatus clypealis, Colymbates piceus. Results showed that the highest rate of the species was in the H. ponticus reaching 5.78 insect / month, and the lowest rate 0.13 insect / type of species C. tripunctatus . Alemdaina station recorded the highest rate of the presence of the species, reaching 3.25 insect / month whereas Qurna Station was lowest rate reaching 1.87 insect / month. The results showed that the highest rate of the presence of the species during the months was in the November at a rate of 4.41 insect / month, while the least insect rate was 0.96 / month for the month of July. The study included the impact of certain environmental conditions and the presence of which degrees air temperature, water, dissolved oxygen, pH and water salinity in the five main stations in the districts of the Basrah province which are Qurna , Almdaina , Shatt al-Arab , Abo-Alkaseeb and the city center of Basrah province. The study recorded the highest temperature of air and water for the month of July was 43.23 o C and 32.58 o C, respectively, while the lowest was 17.07 oC and 18.80 o C, respectively, for the month of January. The results showed a higher rate of oxygen dissolved in the Shatt al-Arab and amounted to 5.50 mg / l while the lowest rate was in the center of the Basrah province and reached 5.25 mg / l. The study indicated that pH values were close to all stations and characterized a light alkali where rates between 7.44 - 8.16 in all the stations as well it was observed that the highest salinity rates were in Abu-Alkaseeb station reached 7.01 ds m-1 while less than the rate of 5.04 ds m-1 for the station of Almdaina. The study found the results of the most important linear relationships and correlation treatments between the population density of the species and attributes measured the highest correlation coefficients were between the presence of species through the expense of numerical density are full with water temperatures and salinity during the months of the year, amounting to -0.84 and -0.79 respectively, while the influence of dissolved oxygen and pH was less than it before as they relate reached coefficient as 0.67 and 0.55 respectively. The results of the biocontrol on the larvae and pupae mosquitoes is superior kind C. tripunctatus on the rest of the studied species was predation rate on larvae 35.22 larvae / day and the pupae 29.78 pupae / day, while the lowest rate was 1.56 larvae / day and 1.33 pupae / day for the type H. clypealis.
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