Insect Pests July 2003 IP-13 Integrated Pest Management for Home Gardens: Insect Identification and Control Richard Ebesu Department of Plant and Environmental Protection Sciences ntensive, high-production agricultural systems have IPM components and practices Itraditionally used synthetic pesticides as the primary Integrated pest management strategies consist of site tool to eliminate pests and sustain the least amount of preparation, monitoring the crop and pest population, economic damage to the crop. Dependence on these pes­ problem analysis, and selection of appropriate control ticides has led to development of pest resistance to pes­ methods. Home gardeners can themselves participate in ticides and increased risk to humans, other living or­ IPM strategies and insect control methods with a little ganisms, and the environment. knowledge and practice. Integrated pest management (IPM) is a sustainable approach to managing pests that combines biological, Preparation cultural, physical, and chemical tools in a way that mini­ What control strategies can you use before you plant? mizes economic, health, and environmental risks. You need to be aware of potential problems and give The objective of IPM is to eliminate or reduce po­ your plants the best chance to grow in a healthy envi­ tentially harmful pesticide use by using a combination ronment. of control methods that will reduce the pest to an ac­ ceptable level. The control methods should be socially Soil preparation acceptable, environmentally safe, and economically Improve the physical properties of the soil including practical. Many commercial agricultural systems use texture and drainage to reduce waterlogging. Improve IPM methods to manage pest problems, and home gar­ soil fertility and soil organic matter by working well deners can use similar methods to control pest problems rotted compost into the soil. in their gardens. Prevent pest build-up with crop rotation, fallowing, The first key to IPM is to identify the pest. This and using resistant crop varieties or crops less suscep­ publication describes the major pests of home garden tible to pests. crops in Hawaii and gives their identifying characteris­ tics. The second key to IPM is to know which stages of Monitoring (scouting) for pests the pest cause damage and which are most susceptible Observe your garden and learn to identify the pest prob­ to management with the various possible control meth­ lems, as well as beneficial organisms. ods. With an understanding of the pest life cycle and its relationship to the susceptible host plant, and with knowl­ Problem analysis edge of the types of control methods available, garden­ Do you have a pest problem? Is it a pest such as an in­ ers can better utilize IPM to manage common insect pest sect or plant disease? Is it a nutrient deficiency or a prob­ problems. The elimination or reduction in pesticide use lem with soil drainage? Is the pest problem major and that can be achieved through thoughtful application of needs control or minor and can be tolerated? IPM strategies will prevent misuse of pesticides and help keep the environment healthy. Published by the College of Tropical Agriculture and Human Resources (CTAHR) and issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Andrew G. Hashimoto, Director/Dean, Cooperative Extension Service/CTAHR, University of Hawaii at Manoa, Honolulu, Hawaii 96822. An Equal Opportunity / Affirmative Action Institution providing programs and services to the people of Hawaii without regard to race, sex, age, religion, color, national origin, ancestry, disability, marital status, arrest and court record, sexual orientation, or veteran status. CTAHR publications can be found on the Web site <http://www.ctahr.hawaii.edu> or ordered by calling 808-956-7046 or sending e-mail to [email protected]. IP-13 IPM for Home Gardens—Insect ID and Control CTAHR — July 2003 Insect identification Simple or gradual metamorphosis If you have an insect problem, you need to know what Eggs hatch and there is a gradual change as the imma­ insect pest you are dealing with and what stage of the ture forms, called nymphs, mature to the adult stage. insect’s life cycle is the most likely to cause damage, as Nymphs have compound eyes and antennae and re­ well as the stage most susceptible to control measures. semble the adults but are smaller, without fully devel­ oped wings, and cannot reproduce. Wings of the adult General insect information develop externally, and there is no resting stage, like a Insects have lived on the planet Earth for about 350 pupa. Nymphs usually live in the same habitat as the million years. Insects have adapted to just about every adults. Development is sometimes called ametabolous type of habitat, including plants, animals, soil, water, in forms without wings, such as collembola and silver­ snow, deserts, buildings, stored products, and people. fish. Insects with gradual metamorphosis include grass­ Most insects are not pests, and it is impractical to at­ hoppers, cockroaches, and aphids. tempt to eliminate all the insects from our environment, Some insects, such as dragonflies, have an incom­ so insect pest management strategies should include a plete metamorphosis. Their nymphs live in water, have variety of techniques. Integrated pest management (IPM) gills, and differ in appearance from the adults; they of insects is designed to use these techniques to reduce emerge from the water and molt into the adult form with pesticide use, use less toxic pesticides, and use environ­ wings, without a resting stage. mentally safe pesticides to keep insect populations be­ low economically damaging levels. Complete metamorphosis Immature stages are normally worm-like and are called Characteristics of insects larvae. Larvae do not have compound eyes, some may Insects are invertebrates (no backbone) with an exosk­ have thoracic legs, and some have leg-like appendages eleton (outer skeleton). Their bodies are segmented with on the abdomen. The last larval stage is a resting stage three major body regions: the head, thorax, and abdo­ called the pupa. The pupa does not feed, usually is not men. Adults have a pair of antennae, a pair of compound active, and often is covered by a silken cocoon. Wings eyes, three pairs of legs, and zero, one, or two pairs of are developed internally, and upon emergence the adult wings. Their appendages and mouthparts come in a va­ expands the wings. Immature and adult stages are usu­ riety of shapes, sizes, and functions. They respire mostly ally different in form and often live in different habitats. through holes in their body called spiracles (for terres­ Insects with complete metamorphosis include butterflies, trial insects) and by diffusion through the body wall (in flies, wasps, and beetles. aquatic insects). Insects are cold-blooded; their body temperature closely follows the temperature of their sur­ Insects and their importance to people roundings. Insects differ from mites, ticks, and spiders, which have two major body sections, four pairs of legs, Injury to plants and lack antennae and compound eyes. Centipedes are Many insects are agricultural pests; they arthropods with one pair of legs on each body segment, • chew leaves, stems, bark, or fruits of plants and millipedes have two pairs of legs on a body seg­ • suck sap from leaves, buds, stem, or fruits ment. Sowbugs are crustaceans, usually with seven pairs • bore and tunnel into bark, stems, twigs, wood, fruits, of legs. nuts, and seeds • cause galls and abnormal growth on plants Insect development • attack the roots of plants in any of the above ways All insects develop from eggs. Most hatch after the egg • lay eggs in plant tissue is laid, but some, like the aphids, hatch within the fe­ • take plant parts for nest or shelters male, and live young are produced. Metamorphosis is • carry other harmful insects to plants the change in form from the egg to adult stage. • vector (transmit) plant diseases. 2 IP-13 IPM for Home Gardens—Insect ID and Control CTAHR — July 2003 Types of pest activity and examples of organisms. Activity in relation to plants Examples of organisms Chewing leaves, stem, fruit Grasshoppers, beetles, caterpillars, slugs Sucking plant sap Aphids, leafhoppers, whiteflies, scales, thrips, mites Boring, tunnels Leafminer, weevils, twig borers, root borers, caterpillars Galls on plants Gall wasp, erinose mites Egg-laying Katydids, fruit flies Waste product contamination Cockroaches, caterpillars, ants, aphids, whiteflies Remove parts for nests or shelter Leaf-cutting bees, some ants, bagworms Carry or protect pests Ants Transmit plant disease Aphids, leafhoppers, thrips Injury to animals or people Annoyance and buzzing Flies, mosquitoes Biting, stinging Mosquitoes, fleas, wasps, bees, bed bugs Transmit disease Mosquitoes, fleas, ticks Infesting animals, people Bot fly, ticks, lice Contamination Cockroaches, flies Damage to products, structures Wood structures Termites, powderpost beetles Stored products, food Flour beetle, meal moth, rice weevil, cigarette beetle Clothing, fiber Clothes moth, carpet beetle Beneficial qualities Pollinate flowers Bees, flower flies Products, honey, wax, silk, dye Honey bee, silkworm, mealybug Biological control Lady beetle, praying mantis, wasps, flies Food source (people, animals) Beetles, flies, grubs Decompose carcasses, dung Maggots, beetles Soil improvement, excavation Beetles, springtails Scientific research, medicine