Atrazine (AT) is a triazine herbicide widely used to control weeds in several crops. De-isopropylatrazine (DIA) and de-ethylatrazine (DEA) are two of the eight primary metabolites produced by AT breakdown in soil and water. The physico-chemical properties of the soil determine their final fate. So, this study aimed to assess the function of clay loam and sandy loam soils in determining their ultimate fate and the potential ecological risks to non-target species during their persistence in soil and transportation to water bodies. The soil in pots was spiked with standard solutions of AT, DEA, and DIA at 0.3 and 0.6 mg/kg for the persistence study. The leaching potential was determined by placing soils in Plexi columns and spiking them with 50 and 100 µg standard solutions. Liquid-liquid extraction was used to prepare the samples, which were then analyzed using GC-MS/MS. The dynamics of dissipation were first-order. AT, DEA and DIA disappeared rapidly in sandy loam soil, with half-lives ranging from 6.2 to 8.4 days. AT and its metabolites had a significant amount of leaching potential. In sandy loam soil, leaching was more effective, resulting in maximal residue movement up to 30-40 cm soil depth. The presence of a notable collection of residues in leachate fractions suggests the potential for surface and groundwater contamination. In particular, DEA and DIA metabolites caused springtail Folsomia candida and earthworm Eisenia fetida to have longer and greater unacceptable risks. If the residues comparable to the amount acquired in leachate fractions reach water bodies, they could cause toxicity to a variety of freshwater fish, aquatic arthropods, amphibians, and aquatic invertebrates. Future studies should take a more comprehensive approach to evaluate ecological health and dangers to non-target species.

Tephritidae fruit flies are considered key insect pest in guava which cause yield loss and degradation of quality. A trial was conducted in guava orchard during 2013 to study residue dissipation rate of two organophosphates, dimethoate and malathion and one synthetic pyrethroid insecticide, lambda-cyhalothrin. The insecticides were applied at recommended and double of the recommended dose on semi-ripe guava fruits. The fruits were randomly sampled at different time intervals, i.e. 0 (2 h), 3, 7 and 10 days after spray. After extraction and clean-up, the residues were estimated using GCMS tandem mass spectrometry. The half-life values at single and double dose applications were found to be 6.72 and 8.15 days for dimethoate, 4.41 and 4.71 days for lambda-cyhalothrin and 3 and 3.3 days for malathion. The residues reached below maximum residue limit (MRL) on zero day following recommended dose application of all insecticides. In double dose application, residues reached below MRL on zero day in malathion and lambda-cyhalothrin and on 3^rd day in dimethoate. Washing of guava fruits removed 42.9 and 45.2% dimethoate, 33 and 36.8% lambda-cyhalothrin, 50 and 54.5% malathion residues at single and double dose applications in 0 day samples. Lambda-cyhalothrin was found most effective followed by dimethoate and malathion for controlling fruit fly in guava.