A comparative study of the growth pattern of the larvae of Culex Linnaeus,1758 in various water bodies and the implications for environmental control

摘要

In anattempt to understand the best water body that could best support the growth ofCulex Linnaeus,?1758 mosquitoes to further elucidate the best method that could be applied intheir control in an assumed evolution of habitat, a total of 50 larvae were collectedfrom a pond. Test was then conducted in five different sources of water and themortality of the larvae in the different sources of water and lengths wereobserved. Mortality of larvae was highest in the urine and water mixed withdetergent where all 10 larvae in both containers died. Their high rate ofmortality could be attributed to the presence of organic salts and urea presentin the urine killed the larvae and also the presence of chemicals (Sodium Sulphate,Sodium Carbonate, and Sodium Silicate) present in the detergent led to thedeath of the larvae. Oxygen which is needed by the larvae for respiration wasin short supply due to the presence of the oil leading to the death of thelarvae. However, the dirty and clean water recorded the least mortality oflarvae as only 1 larva died in each of the containers with dirty and cleanwater. The larvae died probably because of lack of sufficient food. Based onthe mean lengths of the larvae in each of the sources of water, the larvae inthe dirty water had the longest lengths. Dirty water encouraged the growth oflarvae because it has nutrients and many micro organisms such as bacteria andalgae that the larvae feed on for growth and further development. Although thelarvae in the clean water also had longer lengths but they were not as long asthose in the dirty water. On the other hand, the larvae in the water mixed withdetergent and the oily water had shorter lengths while those in the urine hadthe shortest lengths. There was no significant difference in the lengths oflarvae measured from the different water bodies. Based on the findings from ourresult, it could therefore be concluded that dirty water best support thegrowth of Culexdespite the recordedgrowth in the clean water. We therefore infer that inspite the attempt by Culexin undergoing evolution of habitat, thebest environment that supports their growth is still the dirty water.