Uji lengos cacing tanah untuk mendeteksi imidakloprid pada ekosistem terestrial

Abstract

Avoidance test is used to detect pollutant in terrestrial environment by using behaviour of test organism in detecting changes in physical and chemistry of their environment. Avoidance behaviour of two earthworm spesies (Eisenia foetida and Pheretima asiatica) will be used to evaluate the potency of the test with imidacloprid as pollutant model. With chemoreseptor on their prostomium and at anterior segment, earthworm can detect chemical compound in their environment. The influence of concentration and exposure duration of imidacloprid, and also their interaction to the earthworm behaviour in avoiding imidacloprid were studied in this research. This experiment was conducted by using a box of glass divided into two chambers with a separator. One chamber was filled with control media and the other was filled with treatment media. After the separator was lifted out, ten adult earthworm were placed between two chambers. After 12, 24, 48 and 72 hours of exposure, the earthworms were counted in each chamber. One control, three subletal concentration, and letal concentration were applied for this experiment. They were 0, 0.5, 1, 1.5 and 2 ppm for E. foetida and 0, 2.2, 4.3, 6.5 and 8.63 ppm for P. asiatica. Each experiments were carried out with five replicates. Avoidance response from imidacloprid was displayed only by E. foetida. This species did not like the presence of imidacloprid in subletal concentrations by avoiding it and move to control media. This respon could be observed within 24-48 hours. This respon could not be observed in P. asiatica. This was due to the nature of the earthworm which are very active in locomotion. Besides they were less sensitive to imidacloprid than E. foetida, so that P. asiatica was an improper organism to be used as a test organism. Even though the results of this experiment was not so convincing, this test should not be abandoned completely as a method to detect pollutant in terrestrial environment since when using E. foetida the results are quite good.