Apr 28, 2015

Spring is here… and so are a plethora of insects just eager and waiting to eat your trees and plants. The growing season is a wonderful time of the year for trees and plants to flourish and thrive – but be aware; there are creepy-crawlies out there that can threaten the health of branches, limbs, leaves and even the tree itself.

Numerous insects live on trees. While some are harmless, others can cause significant damage, whether by chewing, boring or sucking fluid from leaves.

In the Atlanta area, the primary insects of concerns include cankerworms, lace bugs, spider mites, aphids, pine beetles, ambrosia beetles – which we discussed in more detail in an earlier blog – and, of course, the increasingly threatening emerald ash borers.

Cankerworms are identifiable by their feet – they only have feet at their front and rear and move by inching their rear portion forward in an arching motion. They eat tree leaves for four to five weeks, and may completely defoliate the tree. Repeated defoliation on a mature tree seriously weakens it to the point that it may die, or become vulnerable to another disease.

Lace bugs attack the leaves on trees, feeding on a variety of broad leafed trees. These bugs chew holes in the leaves of trees and suck the fluid out of them. Damage includes discoloration on the leaves – a yellow or white stippling on them, a browning of leaves, or evidence of leaf curl – and eventually early loss of the foliage. Lace bugs can be difficult to spot; they are only about one eighth of an inch long.

Spider mites (which technically are not insects) are usually found on the underside of plant leaves. Even smaller than the lace bug, they are only about one millimetre long, and are mostly red in color. Spider mites cause damage to the leaves of plants by piercing the leaves in order to feed on the fluids. These insects get their name from the silk web they spin around themselves and eggs for protection. Signs of damage include yellow or brown spots on the leaves of infected trees, leaves which have completely turned yellow, or a total halting of growth for the tree.

Boring insects can be the most harmful of all insects to trees if left untreated. Two notable examples of ‘borers’ are the Emerald Ash Borer (EAB), which was discovered in Michigan a little over a decade ago, and the Asian Longhorn Beetle (ALB). The EAB has ruined huge quantities of ash trees every year, while the ALB has been reported in several US States. The EAB has recently been found in Atlanta and as a result, most counties of the greater Atlanta metro area are under quarantine. This means that all wood cut and removed from a quarantined area may ONLY be taken to a processing facility within the quarantined area.

Pine beetles and Ambrosia beetles are very common in the Atlanta metro area. There are several types of pine beetles, the most common presently are Turpentine Beetles. They’re every easy to treat if done soon after discovery. Please see our earlier blog article on Ambrosia Beetles.

Borers cause damage by boring into the stem, twigs or roots of a tree – some might lay eggs which then hatch and cause issues when the larvae burrow even more deeply into the wood.  Damage to the stem can restrict or stop the flow of fluids to/from leaves, which may be starved of moisture, and nutrients, resulting in the tree eventually dying.

Look out for holes in the bark of a tree – which could be entry or exit routes – and tell-tale mounds of sawdust at the base, which are indications that insects have bored their way into the tree. Call an arborist immediately. You may be able to save the tree if you act soon.

For the home owner the difficulty lies first with identifying the presence of insects which are very often barely visible to the naked eye, and second, knowing what to do to treat the resulting problems. Call 404-CUT-TREE for help and assistance in the Atlanta metro area.