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.
Spider Mites - Spider mites are not insects but are more closely related to spiders. These arachnids have four pairs of legs, no antennae and a single, oval body region. Most spider mites have the ability to produce a fine silk webbing. Spider mites are very tiny, being less than 1/50 inch (0.4mm) long when adults. Spider mites have tiny mouthparts modified for piercing individual plant cells and removing the contents. This results in tiny yellow or white speckles. When many of these feeding spots occur near each other, the foliage takes on a yellow or bronzed cast. Once the foliage of a plant becomes bronzed, it often drops prematurely. Heavily infested plants may be discolored, stunted or even killed. Web producing spider mites may coat the foliage with the fine silk which collects dust and looks dirty. Spider mite species seem to be warm weather or cool weather active pests. The twospotted, European red, honeylocust, and oak spider mites do best in dry, hot summer weather. The spruce and southern red spider mites do best in cool spring and fall weather. All spider mites go through the same stages of development. Adult females usually lay eggs on their host plants. The eggs hatch in days to weeks into the first stage, called a larva. Larvae are round bodied and have only three pairs of legs. The larvae feed for a few days, seek a sheltered spot to rest and then molt into the first nymphal stage. The first nymph now has four pairs of legs. The first nymphs feed a few days, rest and molt into the second nymph. The second nymphs feed, rest and molt into the adult stage. The males are usually the size of the second nymph and have pointed abdomens. The females have rounded abdomens and are the largest mites present. Most spider mites spend the winter in the egg stage but the twospotted spider mite over winters as adult females resting in protected places.
Solution - Early detection of spider mites, before damage is noticed, is VERY important. The tiny spider mites can be detected only by a full and thorough leaf inspection (on both sides of the leaf). If you find Spider Mites you must act fast and hit them hard with either a bleach solution (1 tablespoon of bleach to 1 gallon of 95°F, pH balanced, water in a spray bottle.) or use a miticide with Abamectin <
http://pmep.cce.cornell.edu/profiles...ectin-ext.html> or lindane <
http://pmep.cce.cornell.edu/profiles...f-lindane.html> in it. That seems to work best. There are insect predators <
http://eartheasy.com/grow_nat_pest_cntrl.htm> that can help in providing some CONTROL but this does not mean 100% eradication and in a consumable crop that is what we are after. The predator mite can help to control them if chemical sprays are not your thing.
White Flies - White flies behave just like spider mites. The insect hides underneath the leaf, and sucks it's dinner from it. Which results in white spots on the top side of the leaf. White flies are easily spotted with the naked eye. If you shake the plant a little, they'll fly around. They look like little white moths, around 2 millimeters in size.
Solution - A sizeable infestation can be combated with your favorite insecticide. If you're not so anxious to use such strong methods, you can purchase assassinator wasps the ichneumon fly (Encarsia formosa). This natural enemy doesn't sting people, but works well at eliminating white flies. Since it's only a small wasp (smaller than the white fly itself), it takes a while before all the white flies have disappeared. Additionally, you have to put new assassinator wasps out approximately every two weeks.
Thrips - Are small, fast-moving insects with wings. They rasp, or grate the marijuana leaves open, and suck the sap out. Thrips prefer flowering tops, and fresh, young leaves. Affected leaves have shiny, silvery spots. This is caused by the thrips sucking the chlorophyll out of the leaves. In spite of the fact that they're small, you can see them marching in columns on an infested plant.
Solution - Thrips can be fought with your favorite insecticide. Or predatory insects, the thrips' natural enemy is Amblyseius cucumeris.
Lice - Lice are found inside as well as outside. And thrive during the summer months. Lice are the most interested in plants with questionable health.
Solution - There are two methods to kill lice, spraying with insecticide, and setting out assassinator wasps. The problem with most flying predatory insects is that they're attracted to the high-pressure gas lamps we all love to use, which sends most of them to a quick and fiery death.
Slugs/Snails - The common slug is too common a pest to even need much of an introduction. Slugs attack a wide range of plants, causing anything from slight damage to death.
Solution - Unfortunately, there is no foolproof method for eradicating slugs. All one can hope for is to reduce their numbers and protect plants when they're at a vulnerable stage. Toads, frogs, and beetles eat slugs and are worth encouraging in your garden. One of the best ways of dealing with slugs is to use physical barriers. Place plastic bottle cloches around plants, or sprinkle circles of lime, eggshells, or sawdust around plants. Slugs are attracted to saucers or plastic pots of milk or beer (they drown themselves in ecstasy). To be sure you're keeping your slimy slug population under control; collect them by hand at night or on damp days. Try collecting them under a tile or wet cardboard, and squash all eggs you find while digging. Placing a saucer of salt is another method that’s as old as the hills. Martha Stewart recommends coiling a piece of wire around the base of your plants to give slugs a shocking experience. Of course Martha probably doesn't have the same plants in her garden as we do, but we won't tell her if you don't.