Aphids - Aphids are soft-bodied insects that use their piercing sucking mouthparts to feed on plant sap. They usually occur in colonies on the undersides of tender terminal growth. Heavily-infested leaves can wilt or turn yellow because of excessive sap removal. Aphids produce large amounts of a sugary liquid waste called "honeydew". The honeydew that drops from these insects can spot the windows and finish of cars parked under infested trees. A fungus called sooty mold can grow on honeydew deposits that accumulate on leaves and branches, turning them black. The appearance of sooty mold on plants may be the first time that an aphid infestation is noticed. The drops can attract other insects such as ants, that will feed on the sticky deposits. Infestations generally result from small numbers of winged aphids that fly to the plant and find it to be a suitable host. They deposit several wingless young on the tenderest tissue before moving on to find a new plant. The immature aphids, or nymphs, that are left behind feed on plant sap and increase gradually in size. They mature in 7 to 10 days and then are ready to produce live young. Usually, all of them are females and each is capable of producing 40 to 60 offspring. The process is repeated several times, resulting in a tremendous population explosions. Less than a dozen aphid "colonizers" can produce hundreds to thousands of aphids on a plant in a few weeks. Aphid numbers can build until conditions are so crowded, or the plant is so stressed, that winged forms are produced. These winged forms fly off in search of new hosts and the process is repeated.
Solution - Early detection is the key to reducing aphid infestations. The flight of winged colonizers cannot be predicted, so weekly examination of plants will help to determine the need for control. Examine the bud area and undersides of the new leaves for clusters or colonies of small aphids. The presence of these colonies indicates that the aphids are established on the plants and their numbers will begin to increase rapidly. Fatty acid salts or insecticidal soaps are very good against aphids. They apparently work to disrupt insect cell membranes. They require direct contact with the insects and leave no residual effect. Nervous system insecticides, such as malathion, Dursban (chlorpyrifos), and Orthene (acephate), are labeled for use on many shade trees and ornamental plants for aphid control. As with soaps, coverage is very important and a follow-up application may be necessary. Sevin (carbaryl) is not effective against many aphids so it is generally not a good choice for control unless recommended specifically. In fact, applications of Sevin may reduce the number of beneficial insects, such as lady beetles, and increase the potential for aphid outbreaks. Beneficial insects, such as lady beetles and lacewings may eat large numbers of aphids but the reproductive capability of aphids is so great that the impact of the natural enemies may not be enough keep these insects at or below acceptable levels. To keep aphids and other pests off your plants just finely chop1 onion and 2 medium cloves of garlic. Put ingredients into a blender with 2 cups of water and blend on high. Strain out pulp. Pour liquid into spray bottle. Spray a fine mist on plants, making sure to coat both tops and bottoms of leaves.
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