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Corning Gorilla Glass TougherTogether. ET India Inc. Another possible solution being explored, but one that has been met with some controversy: genetically modifying oranges to make them more resilient to pests and diseases. While GMOs could be more of a long-term solution, says Rogers, a more short-term one is naturally cross-breeding oranges to create "new varieties" that can "better tolerate the disease.
However, it would be at least four years before their effectiveness could be measured, when the new citrus trees finally yield, he acknowledged. Forest resources in the North Atlantic states are under siege. The Asian longhorn beetle is menacing "recreation and forest resources valued at billions of dollars" and has the potential to destroy "millions of acres of America's treasured hardwoods," according to the APHIS.
These are among the invasive pests currently under federal quarantine, which is designed to restrict their movement to greener pastures. Some states are following the federal quarantine. In Hawaii, a rhinoceros-looking black beetle is attacking coconut-bearing palm trees. The sucking insects and chewing insects, such as grasshoppers and crickets, have three life stages: 1 egg, 2 nymph, and 3 adult.
This type of development is known as incomplete metamorphosis. There are some groups that are considered to have an incomplete metamorphosis, even though an intermediate stage undergoes a great enough transformation to be called a pupa or pseudopupa. Examples include whiteflies and thrips. The external skeleton of insects is relatively rigid, and cannot be stretched very much. As insects grow, they split the old skeleton, crawl out of it, and harden a new skeleton larger than the old one.
This process, called molting, is controlled by hormones. The time required for development of insects from egg to adult varies from a few days for flies to 17 years for a cicada. Insects may feed on leaves, stems, roots, and flowers of plants.
The chewing insects actually consume the infested parts. Types of leaf feeding by chewing insects include pit feeding on leaves by leaf beetles, flea beetles, and young caterpillars. Irregular notches along the edges of leaves are typically caused by various weevils, larger caterpillars, grasshoppers and katydids.
Perfect semicircular cut portions of leaves indicate the presence of leaf cutter bees. Feeding entirely within leaves is called mining. Leaf miners can be found among beetles, flies, sawflies, and moths. Stem chewing typically is done by borers, which feed internally as larvae. Important borers include longhorned beetles roundheaded borers , metallic wood boring beetles flatheaded borers , engraver beetles, clearwing moths, American plum borer a moth , and a few less commonly encountered moths.
Root chewing insects include species that subsist entirely on plant tissue for development, such as root weevils and root maggots, and those that feed on a combination of soil organic matter and roots most white grubs. Sucking insects remove cell contents e. Some of these sucking insects inject salivary fluids into plants. This secretion may 1 kill plants, as evidenced by armored scale feeding, 2 cause galls to form, as in the case of gall aphids, or 3 kill portions of a leaf, as seen in leafhopper "burn.
Sucking insects balance their nutrition by excreting the excess sugar-water as honeydew, which is objectionably sticky and supports the growth of sooty mold. Honeydew can also lure nuisance stinging wasps, and also attracts ants, which protect the sucking aphids from predators and parasites.
One key to managing populations of honeydew producing insects is to control the ants that protect them. Insertion of sucking mouthparts into plants increases potential for the transmission of plant disease organisms. Sucking insects, such as leafhoppers moving among plants can transmit mycoplasma-like organisms that cause Peach X-disease and aster yellows.
Aphids and leafhoppers transmit viruses to plants. Preventing the transmission of viruses can be the chief reason to control certain insects. An example is the importance of controlling western flower thrips when growing impatiens. Their transmission of tomato spotted wilt virus can devastate a crop being started in a greenhouse.
Some insects cause damage by cutting the plants for egg-laying. Conspicuous among these are cicadas, which during years of peak emergence can cause considerable damage to small branches of trees.
Tree crickets also lay eggs in stems, and while doing so, may transmit disease agents. Many plants offer a suitable breeding place for many kinds of insects. Apples, cabbage, corn, elm, grape, grass, maple, oak, peach, pear, pines, poplar, potatoes, and roses have many serious pests.
However, insects seldom destroy these plants. The threat of damage by insects need not prevent an attempt to grow any of these plants. A knowledge of what to expect and how to control the pests when they are destructive enables anyone to tolerate low numbers of insects. Some insects are perennial pests. Plum curculio, flea beetles, striped cucumber beetles, Colorado potato beetle, plant bugs, white grubs and many others regularly occur in some locations whenever appropriate plant hosts are available.
Other insects seem to be influenced easily by the weather. Temperature and rainfall seem to affect the numbers of aphids, mites, gall midges, and some scale insects. The third type is represented by the gypsy moth, canker worms, and tent caterpillars. The abundance of these pests changes over several years. The "boom and bust" phases are apparently caused by interactions with predators, parasites, and diseases.
The key to successfully growing plants and living with insects is to understand management principles. The need to protect plants is based on whether damaging populations of certain pests are present or expected to be present. The decision to treat plants, for example by spraying with insecticides, should be determined by an economic injury level or aesthetic injury level. These levels define the break-even cost for the extent of damage caused by insects or mites compared to the cost of the control measure.
Preventive measures may be warranted for perennially damaging pests, especially when we lack a method to determine whether a damaging pest population is present quickly enough to react in a timely manner to prevent economic injury. The best strategy for these pests is to base the need for treatment on the past history of the site, with treatment timing dictated by crop development. For example, plum curculio is active every year for approximately one month following fruit set when nighttime minimum temperatures exceed 65 F.
To protect tree fruits, the decision to spray is based on fruit development and predicted moderate night temperatures. Another example is treating lawns to control white grubs. The most effective insecticides work best when applied at the time adults are active, long before a homeowner can determine whether a damaging population will result. To control these destructive creatures, try these methods:. Caterpillars are soft, segmented larvae with distinct, harder head capsule with six legs in the front and fleshy false legs on rear segments.
They can be found on many fruits and vegetables, ornamentals, and shade trees. Caterpillars chew on leaves or along margins; some tunnel into fruits. To deter them:. Cutworms are fat, 1-inch-long, gray or black segmented larvae most active at night. They are found on m ost early vegetable and flower seedlings and transplants throughout North America.
Cutworms chew through stems at ground level; they may completely devour small plants in May and June. For control:. Adults are yellow-orange beetles with ten black stripes on wing covers. They're found on potatoes, tomatoes, cherry tomatoes, eggplant, and petunias throughout North America. These beetles defoliate plants, reducing yields or killing young plants.
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