Understanding and Treating Spider Mites and Aphids

Sometimes it’s the little things you have to watch out for. Certainly this holds true in the case of aphids and spider mites, common summer insects. Knowing what to look for and how to take care of your plants can mean the difference between beautiful summer greenery and plant damage, disease or mold.

Acyrthosiphon_pisum_(pea_aphid)-PLoSWhat Are Spider Mites? What Are Aphids?

Spider mites are very small arachnids that primarily live on the undersides of leaves. They can be found in- or outdoors, and feed by sucking the contents out of plant cells. Two common mite species to the area are the spruce spider mite and two-spotted spider mite. The spruce spider mite is active during spring and late fall when it’s cool, going dormant in the hot summer; the two-spotted spider mite is most active in the heat.

Aphids are small green or brown insects. There are many species of aphids; most species only eat one kind of plant, while some feed on many kinds of plants. They feed on the sap of the plant, which can stunt growth, leave the plant vulnerable to fungus or spread viruses.

Are My Trees or My Garden Plants Infested? How Can I Tell?

red-spider-mite-controlBecause spider mites are less than a millimeter in size, smaller than the period at the end of this sentence, it can be difficult to tell whether your plants are affected with the naked eye. A convenient way to check is to put a sheet of white paper under a plant you think may be affected, and tap the stem and leaves lightly. If a dusting of tan, green-yellow or red spots fall onto the paper, these are spider mites. You may also see a fine webbing on a plant (much finer than a typical spiderweb) or shiny spherical spots on the undersides of leaves, which are the mites’ eggs. Light damage can look like small speckled brown spots on leaves, while heavier damage could cause the plant to drop leaves altogether — on evergreens affected by the spruce spider mite, damage may not be seen until the mites go dormant.

Aphid species common to Iowa are usually smaller than an inch, though easily visible to the naked eye, can be many different colors, and distinguishable by paired ‘tailpipes’ (cornicles) on the back of their abdomens. They can affect plants ranging from farm crops to ornamentals in your lawn. Aphids excrete a substance called ‘honeydew’ which other insects, like some species of ant, feed on — the substance also creates a breeding ground for black sooty mold, which can kill your plants. Also, since they feed on the sap of your plants, which acts like blood does in animals, plant growth can be stunted or cause leaves to curl and die.

What Can I Do Myself? How Can Quality Care Help Me?

Light mite infestations can be treated with a steady, forceful stream of water, like from a hose (or from the shower, for indoor plants) to wash away the mites. Otherwise, there are miticides available for retail sale. There isn’t really a good form of control for aphids that’s retail-available. The damage can be mitigated by keeping the plant watered, fertilized and otherwise healthy, and by keeping an eye out for mold.

We offer commercial-grade treatments for mites and for aphids that are not available in retail stores and certified, trained technicians to take special care of your landscaping and trees. Request a proposal online or give us a call!

Having concerns about your lawn and landscape? We’re happy to help! Let us know!