We are blessed to live in Hawaii, but we do have challenges when it comes to home gardening and farming. Fortunately, we have resources such as the University of Hawaii College of Tropical Agriculture and Human Resources to make these challenges less overwhelming. The college offers a variety of research and teaching activities. Call or visit the office nearest you in Hilo, Waimea and Kona. County chairman Russell Nagata coordinates programs on Hawaii Island. Call him at 981-5199 for assistance in locating the correct extension personnel or researcher for your needs.
The Cooperative Extension Service, the off-campus arm of our land grant college, is offering a workshop for farmers and others interested in pest management. Orchard Growers Field Day will be held from 8:15 a.m. to 4:30 p.m. Saturday at the Kona Research Station in Kainaliu. To register, call Gina at 322-4892 or email firstname.lastname@example.org.
The workshop will focus on diversifying to reduce gardening and farming risks. You will learn about dealing with fruit flies, banana moth and other bugs that bug you. There will be an opportunity to learn about Korean natural farming, which incorporates indigenous micro-organisms to help control animal waste odors and improve vegetable and tree crop growth.
The program includes a trade show of agricultural companies, crop insurance agents, UH CTAHR Extension programs such as Master Gardeners and folks representing nonprofit agencies such as the Kohala Center. Whether you are a full-time or backyard farmer, it’s a great time to network with folks in agriculture.
In the meantime, let’s check out some of your garden challenges.
As the weather warms, insects with ravenous appetites are on the increase in your garden. Some feed on plants and others feed on plant eaters. Some feed on human beings and our pets. Some can spread devastating diseases.
We have our share of pesky critters that cause big economic loss — imagine what it would be like if we had no termites or fruit flies.
Now that we have pests that cause problems, it’s important to keep a close watch; some are sneaky rascals. The moment you turn your back, they’re apt to zip out from a nearby host plant and begin munching on the best plants in the garden. Not only do insects feed on your plants, but they devour a gardener’s pride and prestige. One way or the other, you’ve got to learn how to get ahead of these creatures with chewing, sucking, piercing or rasping mouth parts.
Some of the worst foes of shrubs and trees are thrips, whitefly, mites, aphids and scales. Young thrips are yellowish, minute, slender creatures. Mature thrips are only about 1/40-inch long. The pests feed by rasping the plant surface and sucking the sap as it oozes from the wound. Thrips often fly to roses, crotons and other ornamentals in huge numbers from nearby plants. The common Malayan banyan is often loaded with thrips. Some nurseries now carry a variety of this plant that is resistant to thrips.
Aphids are a menace to tender shoots and buds because of their rapid reproduction rate. Aphids feed by sucking the sap from the tender plants, causing them to become deformed. These are especially common on citrus.
Nature may take a hand in controlling aphids. If you look at an army of aphids, you may spot a friend, the syrphid-fly larva, deflating the juice from aphid larvae at the rate of one a minute. Another aphid enemy — a little wasp — can deal a death blow to hundreds of the tiny pests by laying its eggs within their bodies. The friendly lady beetle may be gobbling up her share as well.
Red spider mites are eight-legged crawlers no more than 1/50-inch long. They are not true insects. Often there is quite a build-up of damage-dealing spiders before you notice the leaves are taking on an off-yellow color. A hand lens is needed to discover mites. You’ll find some mites are whitish and virtually colorless. Others may be tan, reddish or purple. Many mites thrive when it’s dry and populations decline with wet weather, so regular showers with the garden hose will reduce populations.
There are some 19 species of scale insects that commonly attack plants. Scale insects fasten themselves tightly to the leaves and stems of many different kinds of plants and suck juice from them, turning leaves yellow, stunting growth and killing branches or even whole plants.
Among all kinds of scale insects of many different shapes, sizes and colors, there are two major groups: armored scales and unarmored scales. As a rule, unarmored scale insects have softer shells and are larger than armored ones. Unarmored scales almost always produce a sticky honeydew, while armored scales usually don’t. Often, you can notice ants searching for honeydew before you see the unarmored scales themselves.
Most scales cover themselves with a waxy coating, making it difficult for insecticides to get to them. They are at their most vulnerable stage when recently born “crawlers” emerge from beneath the protective covering of the parent scale and move about, some of them for the only time in their lives. The crawlers travel until they find a good place to eat, then become stationary, begin to grow and produce their protective covering.
The crawlers are too small to be seen easily, but if you’ve noticed the parent scales, you can assume crawlers will emerge when plants start vigorous growth. Many predators feed on scale, so biological controls work for us if we are patient.
If beneficial insects, lizards, frogs, toads and birds are doing a fair job of control, then relax. If the unwanted bugs are getting out of hand, your local farm and garden shop has a number of safe and effective pesticides available. Neem products are an example of one group considered safe. Before using these products, read and follow label directions.
Using natural controls of pests, plus pesticides as necessary, is the approach called integrated pest management. Formally defined, it is a strategy of pest containment that seeks to maximize natural control forces, such as predators and parasites of insects, and to use other control tactics, such as cultural controls only as needed, and with a minimum of environmental disturbances. Pest management organizes a combination of approaches to pest control into a system that maximizes the advantages while minimizing the disadvantages of each method. Pest management requires a knowledge of the population dynamics of the pest and its natural enemies in relation to cultural practices and plant varieties. All control must be considered within the context of the urban, forest or agricultural ecosystems, and the economics of production. Pest management does not exclude the use of pesticides, but attempts, only if needed, to work them into the ecosystem as compatible components of modern agriculture, urban or forest environment.
Our local farm and garden supply stores have a variety of pesticides and alternatives to pesticides available. Whatever you decide to use, read the directions on the label and follow them to the letter. Remember, the best way to avoid insect and disease problems is to not introduce them into our islands in the first place.