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Lawn, Garden & Landscaping

2004-03-01 16:16:00

Much to do about insects

: Last year we had all kinds of problems with insects.  What can we do to get a ‘heads up’ on them for this year?Answer: Since your question did not state what types of trees and shrubs are in your landscape, I will provide some general information about the most common insect problems.  As most of us know, a landscape not only represents a lot of beauty, but also a sizeable investment.  As with most investments, it needs attention.  Every tree and shrub has the possibility of many different types of problems we look for and/or try to prevent.  There are many different kinds of insects and mites that feed on trees and shrubs. Generally, the greater the variety of plants in the landscape, the more insect and mite species you will encounter. The mere presence of an insect or mite on a tree or shrub does not necessarily mean you have to control that problems with insecticides or miticides.Predators such as wasps, ladybugs, and other biological forces play an important part in keeping many insects and mites under control during most years. These forces may break down during some seasons and require the use of chemical and other control measures. Some insects and mites thrive under Kansas climactic conditions so natural forces seem to exert little pressure on them.Some plants require constant attention while others are relatively free of insects and mites. Use non-chemical methods of control whenever possible. Practices, such as sanitation, pruning, use of tolerant species and varieties and the direct removal of pests by hand, are an important part of any control program.Sanitation is the removal and destruction of whole plants. For example, it is a common practice to remove dead and dying elm trees to control Dutch elm disease. This may include removing large branches that are, or may become heavily infested. It may sound wasteful to remove a healthy plant, but if a plant is a potential host or breeding site, you can avoid a heavy infestation to surrounding plants by removing these potential host plants.  Common insect problems to look for:Mites - Several species of mites attack trees and causes the plant to take on an off green color as a result of these sap-sucking pests. Severely infested plants lose their vigor, become unsightly, and may even be killed. If plant foliage begins to turn an off green color and you suspect mites, make a foliage check by holding a piece of white paper under a branch and striking it hard against the paper. The mites are only about 1/50 of an inch in diameter, so you can't see them on the foliage. If the foliage check reveals 10 mites or more, take action.Bagworms - Bagworms will attack and defoliate most evergreens and deciduous trees and shrubs. However, they are particularly destructive to arborvides, cedar, junipers and other ornamental evergreens. Bagworms live inside spindle-shaped bags that they construct while in the larva or caterpillar stage. They construct them out of silk and bits of foliage. They drag these bags wherever they go and use them for protection against their natural enemies. Bagworms overwinter in the egg stage inside the material bag attached to the tree or shrub. The eggs hatch in late May or early June, and small caterpillars begin feeding and constructing the bag in which they stay. You can handpick light infestations, particularly on shrubs and small trees, and burn the bags before the eggs hatch in June. You can also spray half grown to nearly full-grown bagworm caterpillars, but they are difficult to kill.Cankerworms - Cankerworms are known also as measuring worms, inch worms or hoppers. There are two species. Both attack early in the spring just as the leaves are beginning to appear, or they sometimes attack the buds before the leaves open.Beetles - The most damaging leaf beetle in Kansas is the elm leaf beetle. The elm leaf beetle is an introduced pest from Europe, which feeds only on elm. Although most elm species are subject to attack, the beetles usually prefer Siberian elm (commonly called Chinese elm) and hybrid elms. Elm leaf beetle feeding damage may result in partial or complete defoliation of the tree. Severely infested leaves will turn brown, and often drop prematurely. In some cases, the entire tree may be defoliated by mid-summer. The majority of the damage is caused by the larva as it feeds on the lower sides of leaves. Trees that lose many of their leaves as a result of elm leaf beetle damage commonly put out a new flush of growth, which remaining resident insects may consume. Feeding damage by elm leaf beetles seldom kills an elm tree. However, severe feeding will weaken a tree, making it more susceptible to attack by other insects and diseases.Aphids - Hardly a plant exists, cultivated or wild, that is not a host to one or more aphids species. Aphids, like scale insects and the true plant bugs, obtain their food by sucking the sap from plant tissue. Some species feed only on foliage, others on twigs, branches, flowers of fruit, and still others on roots. Many live on several distinct hosts, spending part of their seasonal development on one host and the remainder on another. Aphids are small (seldom over 1/8-in. long), soft-bodied, pear-shaped insects of many colors, such as green, black, gray or red. Most aphids prefer young shoots and leaves. Their attacks may cause serious damage to plants by robbing them of sap, poisoning plants with the salivary secretions injected during feeding, and serving as vectors of viruses that cause galls on leaves, stems and roots. These are the most common insects that are found in our region.  Identification of and what to do with insect infestation can be very difficult unless you have been trained to do so.  It is paramount to do so in the early stages, before major damage occurs.  Before taking the risk of losing the large investment you have in your landscape, I highly recommend consulting with a certified chemical ap

Brad Lechner QUESTION: Last year we had all kinds of problems with insects.  What can we do to get a ‘heads up’ on them for this year?Answer: Since your question did not state what types of trees and shrubs are in your landscape, I will provide some general information about the most common insect problems.  As most of us know, a landscape not only represents a lot of beauty, but also a sizeable investment.  As with most investments, it needs attention.  Every tree and shrub has the possibility of many different types of problems we look for and/or try to prevent.  There are many different kinds of insects and mites that feed on trees and shrubs. Generally, the greater the variety of plants in the landscape, the more insect and mite species you will encounter. The mere presence of an insect or mite on a tree or shrub does not necessarily mean you have to control that problems with insecticides or miticides.Predators such as wasps, ladybugs, and other biological forces play an important part in keeping many insects and mites under control during most years. These forces may break down during some seasons and require the use of chemical and other control measures. Some insects and mites thrive under Kansas climactic conditions so natural forces seem to exert little pressure on them.Some plants require constant attention while others are relatively free of insects and mites. Use non-chemical methods of control whenever possible. Practices, such as sanitation, pruning, use of tolerant species and varieties and the direct removal of pests by hand, are an important part of any control program.Sanitation is the removal and destruction of whole plants. For example, it is a common practice to remove dead and dying elm trees to control Dutch elm disease. This may include removing large branches that are, or may become heavily infested. It may sound wasteful to remove a healthy plant, but if a plant is a potential host or breeding site, you can avoid a heavy infestation to surrounding plants by removing these potential host plants.  Common insect problems to look for:Mites - Several species of mites attack trees and causes the plant to take on an off green color as a result of these sap-sucking pests. Severely infested plants lose their vigor, become unsightly, and may even be killed. If plant foliage begins to turn an off green color and you suspect mites, make a foliage check by holding a piece of white paper under a branch and striking it hard against the paper. The mites are only about 1/50 of an inch in diameter, so you can't see them on the foliage. If the foliage check reveals 10 mites or more, take action.Bagworms - Bagworms will attack and defoliate most evergreens and deciduous trees and shrubs. However, they are particularly destructive to arborvides, cedar, junipers and other ornamental evergreens. Bagworms live inside spindle-shaped bags that they construct while in the larva or caterpillar stage. They construct them out of silk and bits of foliage. They drag these bags wherever they go and use them for protection against their natural enemies. Bagworms overwinter in the egg stage inside the material bag attached to the tree or shrub. The eggs hatch in late May or early June, and small caterpillars begin feeding and constructing the bag in which they stay. You can handpick light infestations, particularly on shrubs and small trees, and burn the bags before the eggs hatch in June. You can also spray half grown to nearly full-grown bagworm caterpillars, but they are difficult to kill.Cankerworms - Cankerworms are known also as measuring worms, inch worms or hoppers. There are two species. Both attack early in the spring just as the leaves are beginning to appear, or they sometimes attack the buds before the leaves open.Beetles - The most damaging leaf beetle in Kansas is the elm leaf beetle. The elm leaf beetle is an introduced pest from Europe, which feeds only on elm. Although most elm species are subject to attack, the beetles usually prefer Siberian elm (commonly called Chinese elm) and hybrid elms. Elm leaf beetle feeding damage may result in partial or complete defoliation of the tree. Severely infested leaves will turn brown, and often drop prematurely. In some cases, the entire tree may be defoliated by mid-summer. The majority of the damage is caused by the larva as it feeds on the lower sides of leaves. Trees that lose many of their leaves as a result of elm leaf beetle damage commonly put out a new flush of growth, which remaining resident insects may consume. Feeding damage by elm leaf beetles seldom kills an elm tree. However, severe feeding will weaken a tree, making it more susceptible to attack by other insects and diseases.Aphids - Hardly a plant exists, cultivated or wild, that is not a host to one or more aphids species. Aphids, like scale insects and the true plant bugs, obtain their food by sucking the sap from plant tissue. Some species feed only on foliage, others on twigs, branches, flowers of fruit, and still others on roots. Many live on several distinct hosts, spending part of their seasonal development on one host and the remainder on another. Aphids are small (seldom over 1/8-in. long), soft-bodied, pear-shaped insects of many colors, such as green, black, gray or red. Most aphids prefer young shoots and leaves. Their attacks may cause serious damage to plants by robbing them of sap, poisoning plants with the salivary secretions injected during feeding, and serving as vectors of viruses that cause galls on leaves, stems and roots. These are the most common insects that are found in our region.  Identification of and what to do with insect infestation can be very difficult unless you have been trained to do so.  It is paramount to do so in the early stages, before major damage occurs.  Before taking the risk of losing the large investment you have in your landscape, I highly recommend consulting with a certified chemical applicator to monitor it on a regular schedule.