Aphids, Crop Damage & Eco-Safe Tips to Rid Them
Sap-sucking Plant Lice, a.k.a. Aphids
A common pest in the flower and vegetable garden are small insects called 'plant lice' or more commonly called aphids. Attacking stressed plants hardest in times of drought, these destructive insect pests are the bane of every gardener and farmer.
There are many different species of aphids and while some feed upon the sap of just one specific type of plant (monophagous) there are some species of aphids that will feed upon any of several hundred different plants.
Aphids pierce the stem, stalk or leaves of their host plant and drink passively of the sap that is forced through the hole they created.
The sheer number of attacking aphids upon any individual plants causes stress to the plant by robbing the living plant of nutrients and fluids that it needs to grow and survive.
The damage that aphid infestations cause can be extensive. Stunted and decreased yields of crops, yellowing and curled leaves and spreading of blight disease are the most obvious indications of the presence of aphids. The visible presence of hundreds or thousands of these small insects on any particular plant is confirmation. Aphids have taken hold of your crops and are causing damage, draining the vitality from the plant. The saliva of aphids is toxic to plant as well. The saliva has been shown to introduce over 100 known diseases and viruses which also adversely affect the quality, yield and even the life of the plant.
The Great Irish Potato Famine of the 1840s in Ireland and crop damage that occurred in other parts of Europe was caused in part by aphids spreading 'late blight' (a water mold) that specifically ravaged potato crops the hardest. Late Blight on a this massive scale caused greatly reduced potato crop yields, disease and starvation that were especially hard in Ireland; an island whereby nearly one-third of the population depended upon the potato crop. The potential for damage they cause to agriculture is great. Controlling aphids by pesticides or other methods and the introduction of blight-resistant strains of crops helps reduce the loss to agriculture.
An Unusual Trait of Aphids
Aphids are the only known insect capable of synthesizing caratenoids which causes their normally green color to be red. They incorporate this color from a unique form of natural genetic engineering called "HGT" ("horizontal gene transfer" 1) whereby they incorporate the genes without actually being an offspring of the donor.
There are spray products derived from natural plant extracts that will eradicate aphids and not harm the many beneficial insects in your garden...
Getting rid of aphids through the use of pesticides generally causes more harm than good as the pesticide also affects the beneficial insects that naturally feed upon aphids as well as other garden pests. These beneficial garden insects include lady bug (lady bird) insects which not only feed upon aphids but the scale they leave behind.
Preying mantises, parasitic wasps, midge larvae and some species of small spiders are also allies to the gardener and farmer for their appetite of the pest aphids.
Weather too can aid to naturally rid aphid infestations. Hot weather can kill the symbiotic bacteria that lives within the gut of some aphid species, and rain causes the winged aphids to not disperse. Inability to disperse far and wide localizes their influence and reduces the widespread damage they might otherwise cause. A hard rain can wash many aphids from the plant to the ground where they will soon perish from exposure, predation and lack of sustenance.
A More Effective Method to Get Rid of Aphids
Aphids are affected by rainwater but they can hide under the leaves and many will survive so even a good hard rainstorm while offering some relief from aphid infestation, is not a full cure. Pesticides will work against aphids but it can also kill the beneficial insects you do not want to harm. Striking a balance between the necessary for intervention and the inadvertent harmful effects is important.
There are spray products derived from natural plant extracts that will eradicate aphids and not harm beneficial insects that do your garden good by hunting & eating the harmful insects. The beneficial insects ideally should not be harmed by whatever aphid-eradication method you use. Kill the pest insects and save the beneficial ones.
Another effective spray that can be used against aphids is just plain water with some dish-detergent soap added. The surfactant properties of the dish-soap coat the body of the aphid, clings and in effect, drowns them. This soapy mixture must be manually sprayed on the stalks, stems and undersides of leaves where the aphids usually hide and in great numbers. Bonus effectiveness if the sudsy water also contains animal fats, -which the surfactant soap would act as a dispersant on the fats & lipids. A few drops of vegetable or olive oil and dish detergent would work in you do not want to use animal fat. The action of both oil and dish detergent soap combined work better than either by itself.
No pesticides are used, helpful insects are preserved and your plants will grow best without the stresses brought on by aphid infestation.