ABSTRACT
Flies are beautiful, diverse, and important. While many are small, drab, and inconspicuous, some flies are large, colorful, and eye-catching, usually seen on flowers or foliage. Flies come in a multitude of shapes, habits, and sizes, and can be considered the ecologically most varied of the insect orders. Because of this diversity, flies affect man in more ways than any other group of animals. For agriculture, some flies are major pests of crops, but others are beneficial by killing such pests either as parasites or predators. Flies are also essential for the successful pollination of many crops, so, for example, without flies there would be no chocolate (Young 1994, National Research Council Committee on the Status of Pollinators 2007). For the environment, flies clean up after us by decomposing our wastes and recycling critical nutrients. Dipteran mouthparts continuously filter out detritus and microorganisms from large quantities of waste water in our sewage treatment systems. Flies decompose dead bodies, excrement, and rotting vegetation. To the detriment of our health, flies carry diseases that cripple us and bring casualties and suffering beyond imagination. The major flyborne diseases today remain malaria (close to half a billion cases and 1.2 million deaths per year) and dengue (tens of millions of cases per year) (WHO 2003), but there are many other devastating diseases and new ones continue to emerge that are transmitted by biting flies. But flies also improve our health. Blow fly maggots provide expert treatment of bedsores and diabetes-related gangrene, and Drosophila, the vinegar fly and the most widely used organism to study genes and genomes, has provided valuable insights into our hereditary disorders (Ashburner 2006). Even for fields like law enforcement and forensic science, flies are critical. Flies are usually the first to find a dead body and there is a range of species that develop at various rates and under different circumstances on those bodies, so knowing the fly species can help determine the time and place of death and even sometimes what the person did before dying (Goff 2001).
