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

Abstract

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