Contents: 1. Introduction. 2. Objectives. 3. Materials and Methods. 4. Objective 1. 5. Objective 2. 6. Objective 3. 7. Objective 4. 8. Discussion. 9. Acknowledgements. 10. References. 11. Appendix 1: Glimpses of the study sites. 12. Appendix 2: Glimpses of the Diptera fauna.