A Guide to Insects From the #1 Orlando Tree Service
Orlando Tree Service Experts Give Advice on Insects
One of the frequently asked questions that we receive as the best tree service in Orlando is, “Which insects are good and which are bad for my tree?” Here is a guide to help you out:
Aphids feed on the sap tissue in leaves or through the bark. They produce enormous amounts of honeydew as their waste. Honeydew produces a sticky film on and underneath infested trees. Due to their feeding on sap tissue, they are easily controlled by systemic insecticides. Aphids do not need to mate and are essentially born pregnant. Because of this, they can build into huge populations over a relatively short period of time.
Ash Flower Gall
Ash flower gall is initiated by the feeding of microscopic mites on the male flowers of ash trees. Control of this pest is quite limited. The galls do not affect tree health but are considered unsightly.
Ash Plant Bug
Ash plant bugs cause damage by their feeding. When they burrow into the leaf with their mouthparts (stylets) they inject saliva, which aids in digestion and uptake of the plant cell contents. The saliva destroys chloroplasts leaving white spots on the leaves and severe infestations can cause leaf curling, and distortion, and may eventually cause the leaf to die. Fortunately, this pest is easily controlled by both systemic and contact insecticides.
Birch leafminer is the larval stage of a small “fly-like” wasp. The larvae feed between the
epidermal layers of a leaf and thus are protected from predators and parasites by the leaf. Once the damage is obvious, it is usually too late to treat as the larvae leave the mine to pupate. Control measures need to be systemic or be timed to coincide with early larval feeding before the damage becomes apparent.
Black Vine Weevil
Black vine weevils are beetles whose larvae feed on the roots of evergreen yew, arborvitae, and rhododendron often causing decline and death. Adult beetles feed on the foliage leaving semi-circular notched leaves behind. Adults feed at night, so the most obvious symptom is leaf notching.
Many insects have the potential to devastate a single specimen tree or whole stands of trees. However, insects that bore into a tree to feed on living wood tissue are at the top of the list. Almost all trees and shrubs are subject to attack from boring insects. Healthy trees can fend off initial attacks by forming callus tissue or by creating toxic compounds that will kill young insect larvae. Trees that are under some form of environmental stress are more attractive to attack and are less able to respond defensively.
Common Gall Makers
Leaf Galls are created by trees as a hormonal response to the saliva of certain insects and mites. Not all leaf galls are insect or mite-induced, some are also responses to fungi and bacteria. Most leaf galls initiated by insect and mite feeding are not harmful to the trees. While they deform the foliage they do not reduce photosynthesis.
Sawflies are non-stinging wasps. Sawflies larvae look like caterpillars but can be distinguished from true caterpillars by the number of stubby pro-legs that are on the end of their body. Sawflies have six or more pro-legs whereas caterpillars usually have two to four pro-legs. Most sawflies that feed on pine and spruce trees feed together in a colony. They can remove the needles from entire branches in just a few days. Fortunately, they are easy to manage with traditional and low impact treatments.
Cooley Spruce Gall Adelgid / Eastern Spruce Gall Adelgid
Adelgids are aphid-like insects that suck the sap out of spruce trees. Their sucking initiates a reaction in the tree that creates the galls in which they reside. By the time the galls turn brown, the adelgids have left. Treatment to prevent gall formation must be initiated before the first feeding by the insects in the spring.
Leafminers are larvae of sawfly wasps that feed in between the epidermal layers of a leaf. As the larvae feed they consume the plant tissue leaving clear mines that, when they die, turn brown and crispy. Usually, by the time the damage is observed, the larvae have already left the leaves and are pupating underground. Control for elm leaf miners needs to be applied before the mines develop. Repeated defoliation by leaf miners can impact the health of infected trees.
Emerald Ash Borer
The Emerald Ash Borer (EAB) has killed millions of ash trees since its discovery in southeastern Michigan in 2002. Native to Asia, this insect was probably introduced to the United States in wood packing material carried on cargo ships or airplanes.
Hard or Armored Scales are aphid-like insects that produce a hard waxy shell to protect themselves from predators and environmental conditions. Armored scale females resemble legless bumps and damage plants with their sucking mouthparts.
Honeylocust Plant Bug
Honeylocust plant bugs cause damage by their feeding. When they penetrate cells of the leaf with their mouth parts (stylets), they inject saliva, which aids in digestion and uptake of the plant cell contents. The saliva destroys cells, causing leaf curling, distortion, and in severe cases leaf death. Fortunately, this pest is easily controlled with systemic and topical insecticides. Damaged leaves will remain on the tree after the plant bugs are gone. Foliage must be examined for active infestation before treatment is implemented.
Adult beetles feed on the foliage and flowers of most ornamental plants from lindens to larch and even corn and grapes.
Pine Needle Scale
Pine Needle Scale is a hard or armored scale. They are aphid-like insects that produce a hard waxy shell to protect themselves from predators and environmental conditions. Pine needle scale females resemble legless bumps and damage plants with their sucking mouthparts. The smaller male scales have wings and while in the nymph stage also feed on plants. Female scales continue to feed as they produce over a hundred eggs under their shell. The mature female dies, but the eggs survive the winter under the protection of the shell.
Soft scales are aphid-like creatures that feed on the sap of trees. Immature scales, called crawlers feed on foliage whereas mature scales feed on branches. All soft scales feed on the sap contents of the tree which means they are susceptible to systemic insecticides. They also produce a lot of honeydew. Dormant oils and contact insecticides can be effective, but only if they are applied to the unprotected crawler stage of the scale. Thus, the timing of contact insecticide application is critical to effective control.
Spruce Spider Mite
Spider Mites can be very destructive to evergreens. Although they are very small their populations build up quickly and when extensive damage is observed it may be too late to treat. Fortunately, chemical treatment will also kill both the mite and the eggs, so one treatment is usually all that is needed.
Twig Girdler & Twig Pruner
Twig pruners and Twig girdlers are beetles that lay their eggs in twigs at the ends of branches and then cut (chew) the branch ends off. The larvae feed on the decapitated twigs and pupate inside the twigs to overwinter.
Two-Lined Chestnut Borer
It is particularly damaging to trees during/after drought periods when populations of the beetles can kill up to 65% of red oaks in forest stands. The best prevention is to reduce the impact of drought or other root stress occurring on trees in urban landscapes.