Integrated pest management (IPM) starts with proper identification and the understanding of what is and is not a pest. This pocket-guide was produced to help people realize not all insects are pests (greater than 95% are not), and that beneficials are available naturally or can be introduced into the landscape to manage pest species. Even non-insects, spiders and scorpions, are great predators of common garden pests. It is hoped that the guide will help reduce the use and dependency on pesticides and the use of poisons in landscapes where people work and play. It is designed to assist homeowners and landscape professionals in the initial identification and familiarization of common pests and beneficial organisms.
Several organisms herein are designated with highlighted “alert!” on a yellow background. They are not presently found in Nevada or are under scientific study. If found, these should be reported to the State Entomologist, see page 3. They are an economically or ecologically important threat and are 1) quarantined by another state or are 2) quarantined by Nevada. As such, they should be prevented from entering the state and if discovered, reported. This protects producers, homeowners, and the environment from loss.
This guide describes the organisms, indicates if they are a pest or beneficial, and if they are under “alert” status. It also gives their associated signs and symptoms, and suggests general management for each. Common outdoor pests and beneficials of Nevada or commerce are discussed, but not indoor or structural pests such as termites, most ants, and cockroaches. Moths and butterflies, which are excellent pollinators of flowers, are not discussed, unless their larvae are pests. Common beneficial arthropods (insects and spiders) are mentioned herein so that they will not be thought a pest and killed. Many beneficial organisms are not described. These include Bacillus thuringiensis (Bt), viruses, fungi, birds, predator snails, nematodes, etc., all of which can play an important role in integrated pest management.
For more information, read “Natural Enemies Handbook, the Illustrated Guide to Biological Control,” UC Press, Berkeley, Pub 3386.
Three indices are included, an alphabetical index of common names, an “alert” index of organisms that should be reported to authorities for specific action to be taken (page 9), and an index describing benefical organisms, pests and their damage to plants, and organisms that may be either (page 10). In the third index, the pest is categorized by the damage to the plant it produces or the location on the plant where it is found, e.g., leaves, buds, trunk, roots, and whether the plant part is dehydrated, distorted, chewed, or bored into with holes. Familiarize yourself with these heading descriptions. Organisms are listed by their generic classifications e.g., San Jose Scale is found as Scale, San Jose.
To ensure a positive identification, samples of organisms should be taken or sent to a local University of Nevada, Reno, Extension office or to the State Entomologist, at the Nevada Department of Agriculture, before control measures are initiated—they may not be necessary! As well, it is important that authorities document where pests are occurring in the state and if a new potential pest is entering the state. They may have to establish a quarantine to prevent a pest’s spread and an eradication program to eliminate those present.
Seasonal scouting of landscapes can establish treatment thresholds for pests on each property. Thresholds, the point at which action should be taken to avoid unacceptable damage by pests, should be understood before control is started. The economic threshold, used mostly in agriculture, is the level of the pest population at which the associated cost of the treatment is equal in value to the expected increase in crop yield. This is seldom used in landscapes where an aesthetic threshold, the appearance of the property or a plant, reflects the economic tolerance of the property owner to pest damage. The cost of the control is often secondary to keeping the landscape pest-free and beautiful. This threshold varies with each person and their available resources. There is also an emotional threshold that may be important where money is not a factor. For example, people fearful of pests never want to see one or they want to protect their favorite plant, maybe at all costs.
Once it is determined that management methods should be implemented, there are many choices among cultural, physical, mechanical, chemical, and biological controls. Cultural control involves adjustments of normal plant care activities, such as water management, crop rotation, and the amount of fertilizer applied. Physical controls are used to indirectly influence the environment by changing temperature, light, and humidity to curtail or prevent pest activity. Mechanical methods include labor, machinery, and materials other than pesticides that are used to exclude, reduce, or kill pests directly. Pesticides may be applied for control, but must be chosen and used carefully. The use of beneficial organisms to control pests is biological control, and may be successful in controlling insects and mites.
The Animal and Plant Health Inspection Service (USDAAPHIS) maintains a list of beneficial biological control agents. The introduction of biological control agents into the state is monitored. Distributors, nurseries, farm, and internet suppliers must work carefully with state and federal agencies when supplying biological control agents. The purchase or distribution of biological control agents into Nevada must be cleared with State Entomologist, Nevada Department of Agriculture, 350 Capitol Hill Avenue, Reno, NV, 89502
“Alert” pests should also be reported to the State Entomologist when found.
Careful handling, release, and management ensures beneficial organisms become established and are effective organisms are live animals and need to receive gentle care at all times.
A permit, USDA-APHIS-PPQ Form 526, is required to move biological control agents into the state. The supplier should provide this service. For additional assistance and regulatory information, contact the State Entomologist, NDOA.
Make sure you correctly identify the biological control agent you are collecting. Contact Extension, NDOA, or USDA-APHIS for assistance. Always get written permission if you are collecting on private or protected land.
Quick transport and care upon receipt is essential. Some predators may require specific control of temperature, relative humidity, and light during transport and handling. Not all insects travel well, a limited time in captivity is best. Properly pack organisms to ensure survival, especially if shipping long distances by commercial carriers. As a minimum, a sturdy, breathable, escape-proof container, a damp cotton ball or sponge, and material to walk on (plant material or tissue paper) should be provided. Temperature control is extremely important during transport and after receipt. Cool, dark conditions are best during most insect life cycles.
depending upon the insect and the stage of its life cycle when it is collected, extended periods of complete dark, or even in some cases only short periods of light each day, will initiate diapause. Diapause is a period of arrested development (enforced dormancy) between periods of normal activity. An insect forced into diapause would not be active upon release and may or may not survive its new environment.
Species should be selected based on their ability to survive and reproduce in the release environment. Quick release upon receipt will aid success. Make sure current environmental conditions protect the release organism from stresses including temperature extremes, drought, traffic, grazing, fertilizer or chemical sprays, and other predators. Only release beneficials when food sources and foliage for protection are available. Avoid dry, hot, rainy or cold, windy conditions.
Biological control can be successfully used in greenhouses, but it may need to be done over many crop cycles. A crop cannot be removed from the greenhouse all at once, doing so may remove the beneficial’s food source or all of the beneficial organisms themselves.
Once established, redistribute a few organisms to several new locations to prevent the colony from being destroyed all at once if something happens to the original area of release.
Improvements may not be noticeable the first season after release. Populations of beneficial organisms must build before becoming effective. Additional help is available from personnel and resource guides at Extension, NDOA, and federal agencies. Use these to assist you in developing your management plan to successfully include biological control agents.
For the complete guide of insects, use the link below to download the PDF version.
Pesticide Safety Education Program
Extension’s Pesticide Safety Education Program provides web-based training for pesticide applicators seeking to apply restricted and general use pesticides safely, properly and according to the law. Pesticide licensure and certification is administered by the Nevada Department of Agriculture.
Master Gardeners of Washoe County
Master Gardeners provide free, research-based horticulture information to Nevadans.
Youth Horticulture Education Program
Youth Horticulture Education Program is the premier program of horticulture projects that involve youth, families and educators.
Johnson, W. S., Graham, J., and Strom, S., 2006, Identification of Common Landscape Pests and Beneficial Organisms in Nevada, University of Nevada, Reno Extension SP-06-08
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