Home Remedy for Ridding Little Black Flies From House Plants http://www.ehow.com/way_5759523_home-black-flies-house-plants.htmlHow to Remove Gnats from Houseplantshttp://www.caringforhouseplants.com/how_to_remove_gnats_from_houseplants-35849.phpFungus gnatsDescription and damage Fungus gnats are small, black, delicate flies often found hovering around plants. Adult gnats do not feed, but lay eggs in the soil which hatch into white, blackheaded, legless maggots. These maggots feed on fungi and decaying vegetable material but may also attack fine plant roots and cuttings. Control Larvae do not survive well in dry soil, so avoid overwatering and allow the soil to dry out occasionally. Adding 1.2 cm of sharp sand on top of the soil in plant pot will discourage egg laying by the adults. If the problem persists apply one of the following materials: Yellow sticky traps placed near the infested plant to capture the adults Ready to use sprays containing pyrethrins. Mist around foliage and use as a spray for adult fungus gnats.http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/webdoc1386