BLACK FLY or BEAN FLY (Aphis rumicis), also called Collier and Black Dolphin. This Fly is found on many herbaceous plants. It is very injurious to Beans; hence, immediate means of destruction must be employed directly the insect appears. Its extermination is an extremely difficult matter; but the following remedies are very effectual: Tobacco Water. This, made and applied as recommended, for Aphides (which see) is a good remedy; but it is rendered more certain by the employment of soapsuds, instead of clear water, in its manufacture. Paris Green (Arseniate of Copper). Owing to its poisonous nature, this should not be used where there is fruit on the trees or vegetables under them; but there is no better destroyer of hard-dying insects. Its application is very simple. Mix 1lb. of the green with 30gals. of water, and well wet the infested parts of the trees, using a fine-rosed watercan or garden engine for the purpose. The operator's hands should be free from sores and scratches, or dangerous ulcerations may ensue. Gas Liquor. If this can be obtained from a gas-house, it should be diluted with twice its bulk of water, and applied in the same manner as Paris Green, being washed off with clean water in a few hours. If the process be repeated on two or three consecutive nights, it will be found certain in its effects; moreover, it is not very poisonous. The finger or thumb, or the Aphis brush, applied early, will often exterminate these obnoxious insects at once. The first of the methods above described is perhaps the most accessible and the safest to use. Poisonous insecticides are more or less dangerous, especially in the hands of the inexperienced. Black Fly is, however, one of the most difficult insects to eradicate, especially if allowed to multiply. A syringing of clean water should follow either of the above applications. See also Aphides.