Aphids, also known as plant lice are small sap-sucking insects and members of the superfamily Aphidoidea.
Many species are green, but others may be white, brown or black.
The frighteningly rapid increase in numbers that aphids are capable of
makes them among the most destructive insect pests in the home garden.
Aphid infestation can turn the cucumber plant on left into the disaster on the right in a very short space of time.
Another sign of aphid infestation is this contorted leaf on the left. Turn the same leaf over and see aphids by the hundreds.
Ants and Aphids seem to have a relationship that is mutually advantageous. It appears, that ants supply protection for aphids from predators and in return collect the sweet honeydew that aphids secrete.
Ant in the center (top arrow) protecting the aphids on the right from the Hover-fly larvae (left arrow)
The good news for the home gardener is that how to kill aphids is really easy. The bad news is that due to their lightening fast reproduction rate they are often a huge problem before they are noticed.
The first line of attack is simply spraying the effected plants thoroughly with a strong jet of water as soon as they are noticed. If infestations are notice early enough and all plants are treated as such your problem will be washed away relatively quickly.
Light infestation on tomatoes
Hose them off
Leaves are aphid free
Begin vigilant and repeated spraying as necessary will usually be enough where the aphid population has not had time to build up too high.
An insecticidal soap solution can be effective in controlling aphids. It will kill aphids on contact but unfortunately has no residual effect. Caution is needed here, as high concentrations or at temperatures above 90 F (32 C) Soap sprays can damage plants.
Worm tea also has natural insecticide properties. Some of the micro-organisms in worm castings eat away at the cellulose layers of insects making it quite effective as an insecticide. Aphids are one pest in particular that are especially vulnerable to this treatment.
The insecticidal properties of worm tea is however nondiscriminatory, it will affect all soft bodied insects including the beneficial insects that nature provided for your gardens protection.
It should be remembered that natural pest control is different from chemical products in that it will usually take several applications to be effective so reapplication will be necessary after rain or watering.
Aphids may also be controlled by some of their natural enemies, in particular ladybug beetles and larvae, hover-fly larvae, parasitic wasps, aphid midge larvae, crab spiders and lacewing larvae.
Ladybug beetle nymph
Mealybug Destroyer Adult Beetle
Mealybug Destroyer Larvae
The adult mealybug destroyer and the mealybug destroyer larvae (Cryptolaemus montrouzieri) are excellent predators on aphids. While their preference is mealybugs they are not particulary fussy when the feast is on.