If you’re a gardener—flowers, vegetables or otherwise—then you’re engaged in constant battle. It’s not an epic “Lord of the Rings” type of battle. No, it’s a Bruce-Willis-in-every-movie-he’s-ever-been-in type of battle; one guy against the mass hoards of greed and corruption.

Sure, you’ll get your butt kicked a little. You’ll probably end up with a broken nose, a couple of cracked ribs and at least one bullet hole. But in the end, you will kill everybody. That is, unless you’re dealing with aphids. With aphids, you need to be even more on your toes. You have to play it smart, because if you’re not paying attention, it’s all over.

I. General facts about aphids

Aphids, also known as plant lice, are minute plant-feeding insects. About 4,000 species of aphids are known, classified in 10 families; of these, around 250 species are serious pests for agriculture and forestry as well as an annoyance for gardeners. They vary in size from 1-10 mm long.

Aphids are in the superfamily Aphidoidea in the homopterous division of the order Hemiptera. Recent classification within the Hemiptera has changed the old term ‘Homoptera’ to two suborders: Sternorrhyncha (aphids, whiteflies, scales, psyllids and so on) and Auchenorrhyncha (cicadas, leafhoppers, treehoppers, planthoppers and so forth) with the suborder Heteroptera containing a large group of insects known as the true bugs; gnat bugs, pond skaters, shore bugs, toad bugs, water boatmen, backswimmers and so on.

More recent reclassifications have resulted in a substantial rearrangement of the constituent families with the Aphidoidea, with some old families reduced to subfamily rank (e.g., Eriosomatidae), and numerous old subfamilies elevated to family rank. They are brown and green.

Aphids contain sucking mouthparts called stylets. They have soft bodies; long, thin legs; two-jointed, two-clawed tarsi; and usually a pair of cornicles, abdominal tubes through which a waxy secretion is exuded. Aphids have two compound eyes and two ocular tubercles made up of three lenses, each of which is located behind and above the compound eyes. When host plant quality becomes poor or is crowded, female aphids will produce winged offspring that can disperse to other food sources.

Important natural enemies include the predatory lady beetles (Coleoptera: Coccinellidae), hoverfly larvae (Diptera: Syrphidae), lacewings (Neuroptera: Chrysopidae), and entomopathogenic fungi like Lecanicillium lecanii and the Entomophthorales.

Aphids are found worldwide, but they are most common in temperate zones. It is possible for aphids to migrate great distances (mainly through passive dispersal, riding on winds) depending on the weather patterns; for example, the lettuce aphid spread from New Zealand to Tasmania by this travel method. They have also been spread by human transportation of infested plant materials.

II. Aphids as pests

Aphids are sneaky and inconspicuous little beasties. They can show up, breed like crazy and completely destroy your flowers, vegetables and even trees before you ever know there’s a problem. There are many species and colors of aphids. They come in shades of green, red, brown, black and yellow and almost all have fat little pear shaped bodies with several little tubes poking up out of the backend, called cornicles.

Many, but far from all, aphids are monophagous (i.e. feeding only on one species of plant). Others, like Myzus persicae, feed on hundreds of plant species across many families. Similar to related families, aphids passively feed on sap of phloem vessels in plants. This sap is kept under high pressure, so once a phloem vessel is punctured, it is forced into the food canal. As they feed, aphids often transmit plant viruses to their food plants. These viruses can sometimes kill the plants.

Some species of ants "farm" aphids, protecting them on the plant they eat, and eating the honeydew that the aphids secrete; this is a mutualistic relationship. Aphid honeydew is rich in carbohydrates, of which the aphids ingest an excess, being phloem-feeders. Many aphids are hosts to endosymbiont bacteria, Buchnera, which live in specialized cells called bacteriocytes inside the aphid. These bacteria synthesize some essential amino acids that are absent in the phloem that the aphids eat.

Aphids feed by piercing plants and sucking out their juices. In doing so, they can transmit viruses that cause yellowing, curling and distorted growth. Aphids also secrete honeydew, a sticky substance that often results in the colonization of an ugly, sooty black fungus. The following are suggestions to help keep your gardens and plants safe and healthy.

III. Basic Aphid Control

* Frequent Inspection: Catch them early. One “colonizer” can produce up to eighty offspring in as little as a week and is capable of doing so several times. Slowly walk through your garden several times a week while paying close attention to the underside of leaves. Also check for aphids on newly purchased plants and transplants.

* Don’t over-fertilize: Aphids prefer the new growth that is found in abundance in overly fertilized plants. Use only slow release fertilizers. It is also a good idea to grow plants inside or under a cover until they are large enough to be a little more tolerant.

* Spray with water: A strong spray of water is an effective way to dislodge aphids from your plants. Most dislodged aphids will be unable to return to the plant. The Bug Blaster is a hose attachment that works well for this.

* Prune away colonies: Aphids maintain the right to assemble. If you see a section of the plant containing aphids galore, snip it off and dispose of it. It doesn’t cure the problem, but it will slow the advance.

* Try a home remedy for aphids: You can kill aphids by spraying, especially under the leaves, with a solution of two teaspoons of mild dish or laundry soap in a bottle of lukewarm water. The soap washes off the aphid’s protective waxy coating and causes dehydration.

You can also mix three parts lukewarm water to one part vegetable or horticultural oil and a couple drops of dish soap. This mixture can be sprayed on to clog the respiratory spiracles of aphids. Spray once a week, taking turns between solutions.

If you’re using these solutions on food plants, be sure to wash them before eating. If using the oil solution, don’t spray on very hot and sunny days, as the oil can magnify the sun and possibly harm the plant.

IV. Natural Aphid Control

* Diatomaceous Earth: This is a natural insecticide that’s safe for people and pets. Scatter around the garden and plants for effective aphid elimination.

* Neem Oil: This oil is extracted from the seeds and fruits of an Indian evergreen and is used for repelling aphids without bothering beneficial insects such as ladybugs and bees.

* Yellow Traps: A yellow glass filled with water and a couple drops of soap to break water tension will lure aphids into it and cause them to drown. A yellow sheet of paper or tag board with a sticky substance such as double-sided tape on it also works for trapping aphids.

V. Biological Aphid Control (Predators)

* Ladybugs and lacewings are both highly effective predators of aphids. These insects can easily be purchased live from many Internet vendors or lured to your yard using Safer Ladybug Lures.

* Ladybug adults and larvae both enjoy a nice aphid snack.

* Putting a ladybug house in your garden will help ensure a good population.

* The larvae of lacewings are voracious predators of aphids.

* Wrens are also known to eat aphids. Accommodate these birds by placing houses in trees.

VI. Killing Aphids

If you play things smart, getting rid of aphids does not have to be a terrible ordeal. There are plenty of products available that kill aphids. The most common and effective application types of aphid pesticides are IGRs, insecticidal soaps and oils and pyretherins.

IGRs: Insect growth regulators, or IGRs, can work in several ways. They can mimic juvenile hormones so the aphid insect doesn’t reach sexual maturity, they can interfere with the production of chitin for the exoskeleton and they can interfere with the process of molting. Azatin, Enstar 2 Neemasad, Neemix and Preclude are all effective IGRs.

Insecticidal soaps: If you want to use something a little less harsh for controlling aphids, you may wish to look into insecticidal soaps and oils such as Safer Insecticidal Soap, Bon-neem Insecticidal Soap or any horticultural oil. These products are sprayed directly onto plants and aphids and work by trapping and suffocating, washing away the aphid’s protective waxy coating, or by altering the permeability and structure of the cell membranes. This can cause the contents of the cells to leak out, dehydrating the aphid.

Pyretherins: This is another type of aphid treatment that is commonly found in sprays. Pyretherins are an extract of the chrysanthemum flower. Synthetic and equally effective forms are called pyrethroids. The brand Safer uses these in their insecticidal soaps. Bonide, Schultz and Pyola are other good brands.