Pesticides and Pesticide Safety PDF

ENT-70 Pesticides and Pesticide Safety By Lee Townsend, Extension entomologist, University of Kentucky. thought of as a temporary solution to a pest problem, not the In th...

ENT-70 Pesticides and Pesticide Safety By Lee Townsend, Extension entomologist, University of Kentucky. thought of as a temporary solution to a pest problem, not the In this chapter: way to solve it. Ideally, a pesticide helps to reduce losses or damage until the conditions leading to the outbreak change or Types of Pesticides 01 those conditions can be corrected. Accurate identification is the first step in an effective pest The Pesticide Label 02 management program. (See Chapter 7, Insects, in this manual Exceptions to Label Instructions 03 for more information.) Identification is the key to all kinds of Pesticide Formulations 03 information about the pest, including its life cycle, behavior, and recommendations for effective management. Incorrect Application Equipment 04 pest identification is a leading cause of pest control failures and Calibrating Sprayers 04 improper use of pesticides. Safety 06 Your county office of the Cooperative Extension Service can help with pest identification and control recommendations. Other Safety Issues 06 Diagnostic labs in plant disease, insect, and weed identification Integrated Pest Management  07 are also available, along with help in how to take useful pest samples. Most of these diagnostic services are free. Credits 08 Types of Pesticides P est is not a biological term for an organism’s environmen- tal role as are the words plant, herbivore, predator, and Herbicides scavenger. It is a term for an organism that is either caus- Herbicides are pesticides that kill plants. Selective herbicides ing damage or is somewhere where it’s not wanted. Pests can are used in lawns, landscapes, and gardens to control unwanted include plants, insects and their relatives, and microorganisms plants without damaging desirable plants. Nonselective her- that cause plant diseases. Often, pests are a problem because we bicides are used to kill all plants in an area. Selective (and in use cultural practices or create conditions favoring organisms some cases nonselective) products are used as spot treatments that they feed on, compete with, or infect. to control weeds in turf and ornamental landscapes to remove Key pests are present and often cause enough damage to undesirable species growing near desirable plants. require regular control (for example, Japanese beetles on roses). A herbicide’s mode of action is the way it affects a plant. Occasional pests require control during some years because of Some herbicides damage leaf cells, causing them to dry up; favorable weather conditions (such as fireblight on crabapples). others reduce the nutrient uptake. A few interfere with the Sporadic pests do not require control most years but may be plant’s ability to grow normally or to conduct photosynthesis. very damaging in certain circumstances (such as periodical The mode of action often dictates when and how a herbicide is cicadas on newly established trees). used. Herbicides must adequately make contact with and enter Some natural forces act on all organisms, causing their num- the plant. Then, a sufficient amount of the herbicide must move bers to rise and fall from year to year. You may not be able to alter to the site of action to produce the desired effect. the effect of natural forces on a pest population, but you can be To inhibit germination or seedling growth, use preemergent aware of their influence and take advantage of them whenever herbicides. To control weed seedlings, these herbicides must be possible. These natural forces include climate, natural enemies, applied to the soil before the seedlings break through the soil geographic barriers, food and water supply, and shelter. surface. In order to come into close contact with germinating Unfortunately, natural controls may not act quickly or weed seeds, these products require rainfall or incorporation completely enough to prevent unacceptable injury or dam- into the soil. Some products do not move within the plant, age. That is when other control measures must be used. Those so injury symptoms occur only at the site of uptake. In con- measures include host resistance, biological control, cultural trast, systemic herbicides enter through the roots and move control, mechanical control, sanitation, and chemical control, up. Their effects are most obvious where the product tends or pesticides. to accumulate. The active ingredient in a pesticide product is a chemical Postemergent herbicides are applied to the foliage of growing that, when used according to label directions, can reduce or weeds. Those that become active upon contact kill the plant by control a pest problem. A pesticide application should be destroying leaf and stem tissues. They require thorough spray CHAPTER 11 Pesticides and Pesticide Safety coverage. In contrast, systemic postemergents move within used against sap-feeding pests that do not eat plant tissue and leaves and other green parts to growing points, where they require thorough spray coverage. An insecticide may work as a act. These products vary in their ability to move within a plant. stomach poison against caterpillars or beetles and as a contact Factors that affect how well these herbicides work include insecticide against aphids or scale crawlers. These products characteristics of plant leaf surface, plant size and age, water are broken down by moisture, sunlight, or microorganisms, so stress, air temperature, humidity, and herbicide additives. their residual effect is limited. Consequently, correct timing of Differences in the amount of herbicide uptake within the applications is important. plant often explain the year-to-year variation in herbicide Systemic insecticides are absorbed into plants through effectiveness. the roots or foliage. They can be particularly effective against Plants that can rapidly degrade or deactivate a herbicide sap-feeding insects such as aphids and may provide control of can escape its toxic effect. However, plants under stress (such some borers and leaf miners. Uptake of a systemic insecticide as hot or cold temperatures, high humidity, or physical injury) by the roots and movement to the pests’ feeding site may take may be affected by herbicides that they normally tolerate. Also, several weeks, so this type of insecticide may have to be applied misapplication, especially at excessive rates, can overwhelm the several weeks before the pests are active. Systemic insecticides ability of the plant to degrade or deactivate the chemical and can remain in the plant at effective levels for a long period of result in plant injury. time and may have an impact on beneficial insects. While many insecticides affect the insect’s nervous system, Fungicides products with different modes of action are being used—those that target muscles, insect development and metamorphosis, Fungicides are pesticides that destroy or inhibit the growth or parts of the nervous system that are distinctive to insects. of fungi. Contact fungicides, sometimes called protectant fun- The active ingredients in organic insecticides typically come gicides, remain on plant surfaces after application and do not from plant extracts (pyrethrins, neem), products from soil enter plant tissue. In order to be effective, contact fungicides microorganisms (Bt, spinosyn), or plant fatty acids (insecticidal must be on the plant’s surfaces before infection begins. soaps). The spectrum of pests affected and the length of control Systemic fungicides are absorbed into the plant and moved following an application of organic insecticide may be limited up within the water-conducting tissue (xylem); downward mobility is limited. Systemic fungicides sometimes can suppress the fungus after it has infected the plant. The Pesticide Label Fungicide labels usually provide a range of application rates The pesticide label is the way the manufacturer tells you and intervals. Fungicides can be used as a preventive (usually how to use a product safely and effectively. Always read the at low rates and/or with long intervals between applications) label before you buy and use a product. Check the directions- when a disease outbreak has not yet occurred but when weather for-use section to be sure that the plants, insects, or patho- favorable for disease is expected. Fungicides may also be used, gen, and the site that you intend to treat are listed. Be sure often at higher rates and/or at short intervals, after an outbreak you understand how and when to apply the pesticide with has occurred and disease pressure is high. Such applications appropriate equipment. cannot cause sick tissue (yellow or brown leaves, rotted roots) to become healthy again, but they can protect uninfected tis- sue and new growth. These applications are 16 10 1 only effective if the turf is actively growing. Insecticides 11 Insecticides can be classified as either 12 2 broad-spectrum insecticides, which can 13 kill a variety of insects (caterpillars, beetles, 3 aphids, etc.) or as selective insecticides, 8 which affect a limited range of species (for example, caterpillars only) and can help to 14 9 preserve beneficial species. Stomach poisons kill insects with chew- 5 ing mouthparts after they feed on treated 17 6 4 plant tissue, while contact insecticides 15 7 must be absorbed into the body to kill the target. Contact insecticides often are (See the next page for explanations of numbered sections on pesticide label example.) 11-2  Pesticides and Pesticide Safety CHAPTER 11 (Continued from previous page) 11. The note to physician lists treatment information and antidotes and Pesticide Label Sections Explained often provides an emergency phone number for further information. 1. The product name or trade name appears in large print at the top of 12. Precautionary statements identify potential hazards and recommend the label. ways that the risks can be minimized or avoided. Types of precaution- 2. Type of pesticide—the label must identify the type of pesticide or the ary statements include “Hazards to Humans and Domestic Animals,” types of pests that it controls. “Environmental Hazards,” and “Physical or Chemical Hazards.” 3. The ingredient statement must include the concentration and common 13. Hazards to humans and domestic animals. The signal word is listed fol- (generic) and/ or chemical name of each active ingredient in the product lowed by statements indicating which route(s) of entry (mouth, skin, lungs, and percentage of inert ingredients. eyes) are most likely to be harmful and must be particularly protected. Many pesticide products, even though produced by different manufactur- The label will then provide specific action that can prevent overexposure ers, contain the same active ingredient. By purchasing pesticides according to the pesticide. Protective clothing and equipment required to handle to the common name you will be sure you are getting the correct active or apply the pesticide will be listed. ingredient no matter what the brand name is. When comparing two different 14. Environmental hazards warns of pesticide risks to wildlife, birds, fish, products with the same active ingredient, be sure to compare the amount bees, and the environment and provides practical ways to avoid harming of active ingredient in each product. Often, different products will contain them. Some examples are “This product is highly toxic to bees exposed to the same active ingredient but the concentration will vary. Make compari- direct treatment or residues on plants,”“Do not contaminate water when sons based on use rates of pesticides containing the same amount of active cleaning equipment or when disposing of wastes,” and “Do not apply ingredient. where runoff is likely to occur.” For example, Sevin is a brand name of a common insecticide used in the 15. Physical or chemical hazards lists any special fire, explosion, or chemi- garden and landscape. Its common name is carbaryl; the chemical name cal hazards the product may pose. is 1-naphthyl N-methylcarbamate. Being able to recognize the common 16. Directions for use begins with this statement: It is a violation of Federal name may allow you to find the pesticide you want under a different brand law to use this product in a manner inconsistent with its labeling. The name. It may be sold as a 50% wettable powder (WP) or a 25% WP. The actual instructions list what pests the product will control and the plants, crops, concentration of the active ingredient in the spray tank will be the same, or sites the product is intended to protect. The directions also provide regardless of the amount in the product. The use rate of the 25% WP per information on when, where, how, and in what form the product should be gallon of water will be twice that of the 50%WP. applied, proper equipment to be used, correct dosage, mixing directions, 4. The net contents tell how much product is in the container in units of compatibility with other often-used products, minimum time between liquid or dry measure. the application and entry into the treated area for unprotected persons, 5. Name and address of the manufacturer. and possible problems with plant injury. 6, 7. The EPA registration number is unique for each pesticide product. It Harvest interval: When used on fruits or vegetables, there may be a identifies the manufacturer and product and indicates that the product period of time that must elapse from application until the residue drops has been approved by the EPA for the listed uses. The EPA establishment to a level at which the crop can be safely harvested. It is a mistake to number identifies where the product was produced. assume that a residue can be washed off if the crop is harvested before 8. All products must bear the statement “Keep Out of Reach of Children.” the waiting period is complete. The harvest interval is often listed as a 9. The signal word indicates the acute toxicity of the product. number in parentheses following the crop name. 10. The statement of practical treatment lists the first-aid treatment that 17. Storage and disposal directions: This section of the label will tell you should be given in case of accidental exposure to the pesticide. how to store and dispose of the product correctly. Pay attention to specific temperature conditions that are listed. What pesticide label signal words mean: Signal Word Toxicity Approx. Lethal Human Dose Danger-Poison/Danger Highly toxic or harmful to skin/eyes A few drops to a teaspoon Warning Moderately toxic 1 teaspoon to 1 tablespoon Caution Low toxicity to relatively nontoxic 1 tablespoon to 1 pint or more Exceptions to Label Instructions Pesticide Formulations Federal law allows pesticides to be used in some ways not A pesticide formulation is a mixture of chemicals (active specifically mentioned in the labeling. Unless it is a violation ingredient + inert ingredients) that control a pest. Different of the state law, you may do the following: formulations are developed for safer, easier handling, mix- Apply a pesticide at any dosage, concentration, or frequency ing, or application; reduction of drift off-target; or specific less than that listed on the labeling application equipment. Apply a pesticide against any target pest not listed on the labeling if the application is to a plant or site that is listed Liquid Use any appropriate equipment or method of application Emulsifiable concentrates (EC or E) package the active that is not prohibited by the labeling ingredient with a solvent and an emulsifier so it can be mixed Mix a pesticide or pesticides with a fertilizer if the mixture with water and applied with a sprayer. ECs are easy to pour is not prohibited by the labeling and measure, but the solvent can damage the leaves of some Mix two or more pesticides if all the dosages are at or below sensitive plants (the solvent has “phytotoxicity”). Also, an EC the recommended rate formulation is easily absorbed if spilled on the skin. 11-3 CHAPTER 11 Pesticides and Pesticide Safety Flowables (F) contain the active ingredient on very fine particles in a milkshake-like liquid. A flowable is easy to pour Application Equipment and measure accurately, but it does not dissolve in water. The Pesticide application equipment comes in all shapes, sizes, small particles are suspended, so the diluted spray must be types, and prices. Select equipment that fits your needs and agitated regularly to keep the particles from settling to the situation. Following are various types of application equipment: bottom of the tank. Flowables have no solvent, so there is less Hose-End Sprayer—These small, inexpensive sprayers are chance of leaf burn. designed to be attached to a garden hose (Figure 11.1). With some sprayers, a small amount of pesticide is mixed with Dry water—usually no more than a pint—and placed in the recep- tacle attached to the hose. With others, a pesticide concentrate Dusts (D) are fine clay or talc-like products with a low is already in the container, which is connected by a tube to percentage of active ingredient. A dust is ready to apply and the hose opening. When the water is turned on, the suction requires no mixing or cleanup. However, it is hard to treat the created by the water passing over the top of the tube pulls the lower surfaces of leaves and large amounts drift off target. concentrate up and into the water stream. Granules (G) have an active ingredient that is on or in small Potential problems include poor spray distribution, drift clay particles that are applied with a spreader or shaker can. onto the applicator, and drift onto non-target areas. Metering Granules are designed to let the pesticide fall to the soil surface of the concentrate into the water stream can be inaccurate, rather than stay on the foliage. since it is determined by the water pressure. These sprayers put Wettable powder (WP or W) formulations are made by out an excessively high volume of spray for most needs, using putting the active ingredient in a fine powder. They are like a excessive pesticide. All hose-end sprayers should be equipped dust formulation but with a much higher percentage of active with an anti-back siphon device to prevent the pesticide from ingredient. WPs are mixed with water and sprayed on trees or being drawn back into the water system if there is a drop in plants. This type of formulation needs continuous agitation in water pressure. the spray tank to maintain it in suspension. Inhalation and skin/ Compressed Air Sprayer—The spray is mixed in a small tank, clothing exposure is a problem. generally one to three gallons (Figure 11.2). A hand-operated Soluble powder (SP) is an active ingredient in powder form pump supplies pressure during application. A uniform spray that dissolves in water. concentration can be maintained because the pesticide is mixed with a known quantity of water. Frequent agitation of the spray Other mixture is necessary when using a dry formulation (WP, W, D, Ready-to-use (RTU) products are sold in aerosol cans or G, or F). The applicator has excellent coverage control, so this hand-pump sprayers. No mixing or cleanup is necessary. This sprayer is a good choice for treating flowers, shrubs, and small approach is efficient when a small number of plants need to trees, but the spray will not reach into tall trees. be treated. Hand-Pump Sprayer—These sprayers can be used to treat Baits (B)are made by adding the active ingredient to an edible individual plants or small groups of plants. Many ready-to-use or attractive substance. Baits are often used to control slugs, formulations are available for this type of container. snails, or small ground insects and rodents. Calibrating Sprayers Label instructions for spraying pesticides on plants usually are based on mixing specific volumes of product and water (for example, one fluid ounce in one gallon of water) and wetting the plants to the dripping point. Sprayer calibration is not neces- sary. Over-treating can occur if more product per gallon than specified on the label is added or if the foliage is wet excessively, both of which can injure leaf tissue, so the applicator should decide how much application to spray. Label instructions for treating turf or soil, in contrast to those for plants, are usually based on a specific amount of product, such as three fluid ounces in two to five gallons of water per 1,000 square feet. Calibration is required for turf and soil application—so that the area can be treated evenly at the recommended rate, the applicator needs to know both the sprayer output (ounces per minute) and the amount of time Figure 11.1. Hose-End Sprayer Figure 11.2. Compressed Air Sprayer needed to treat a specific area. 11-4  Pesticides and Pesticide Safety CHAPTER 11 Sprayer calibration is relatively easy and should be done spraying at a low pressure and using a large nozzle opening. before the start of each growing season. The delivery rate will Generally, early morning and late evening are the safest times vary with the air pressure in the tank and size of the sprayer of day to spray to reduce chance of drift. nozzle opening. Pressure in the tank will drop as you spray, Vaporization is the evaporation of an active ingredient dur- so be sure to pump frequently in order to maintain a uniform ing or after application. Some pesticide vapors can cause injury. delivery rate. Also, check regularly to make sure the nozzle High temperatures increase vaporization, so choose pesticide opening has not become plugged. formulations that do not evaporate easily, and spray during the Here is the procedure for calibrating a sprayer: cool part of the day. Some products, such as 2, 4-D, are very vola- 1. Fill the tank with water and pump up the tank pressure. Use tile under favorable conditions. These products should not be a stopwatch as you spray water into a pint jar to determine used near highly sensitive plants such as grapes and tomatoes. how long it takes to deliver a known amount. Suppose it takes Do not apply when it is windy or when temperatures following 30 seconds to deliver one-half cup of water, or one minute to application will climb above 85°F. deliver one cup (eight fluid ounces per minute).. Mark the delivery time on the sprayer for future use. Cleaning Equipment 2. Mark off a known area on a driveway or hard surface so Thoroughly clean all equipment immediately after use. Do you can see the water deposit (for example, ten feet by ten not store diluted pesticides in the spray tank. If you have excess feet) and measure the time it takes to spray the area evenly and thoroughly at a normal walking speed, which will tell pesticide, spray it over an area or on specific plants that are permitted by the label, first checking the label to determine you how long it takes to spray 100 square feet. If it takes 30 what the safe areas are. Thoroughly clean all spray equipment seconds to spray 100 square feet, it will take five minutes to inside and out with clean water, and don’t forget to flush hoses spray 1,000 square feet. At eight fluid ounces per minute, you and nozzles. Use caution to ensure that the cleaning water does will use five cups, or 40 ounces, of water. If the label calls for not damage crops. Do not dump the rinse water in a confined three tablespoons of pesticide for 1,000 square feet, those area where it will be concentrated and may become a pollutant. three tablespoons must be mixed with 40 ounces of water Instead, spray the rinse water over a broad area, further diluting to achieve proper spray coverage. the pesticide. Never rinse pesticides down the drain! Mixing Pesticides Storage and Disposal Pesticide compatibility exists when two or more pesticides Use and store pesticides away from children and animals. can be mixed together without causing adverse effects such as The best solution to the problem of what to do with excess jelling, forming of clumps in the tank, or the pesticides remain- pesticides is to avoid having them—buy only the amount ing unmixed. needed for a year or a season. Calculate carefully how much Synergism occurs when mixing of two or more pesticides diluted pesticide is needed for a job and mix only that amount, increases their activity. Synergism may increase control or result and use all the mixed pesticide in accordance with labeling in the need for less chemical. It may also be more harmful to a instructions. nontarget organism. A synergistic effect can also be undesir- If you must store pesticides, store them in their original able, causing death or damage to the organism that is being containers in a locked cabinet. They should be protected from protected. No chemicals should be mixed together unless the label specifically says they are compatible. temperature extremes, because some can be damaged upon freezing and others can be altered by heat. Do not store pesti- When mixing of two or more pesticides results in reduced cides in the home! effectiveness, it is called antagonism. To dispose of empty containers, first rinse them out, pouring In some cases, pesticide labels include information about the rinse water into the spray tank. Rinse three times, allowing tank mixes and recommend or caution against specific combi- 30 seconds for the water to drain between each rinse. Before dis- nations. Pesticides can be mixed unless prohibited by the label, posing of the cans, wrap them in newspaper and secure them. but the applicator assumes responsibility for any problems that The empty containers are best placed in refuse cans destined occur. for a sanitary landfill. If possible, break the containers before disposal. Do not burn paper containers. Some Application Precautions Never re-use empty pesticide containers other than to refill Before adding pesticide, always check application equipment them with the original pesticide. Never allow children to play for leaking hoses or connections and plugged, worn, or dripping with empty containers. nozzles. Before spraying, clear all people, toys, and pets from the area to be sprayed. To minimize drift, apply pesticides only on days with light breezes. If moderate winds (more than 10 mph) arise while you are working, stop immediately. Reduce drift by 11-5 CHAPTER 11 Pesticides and Pesticide Safety Common Reasons for Control Failures Personal Protection If the pesticide doesn’t work, ask yourself these questions: The minimum protective equipment to wear during the mix- 1. Was the pest identified correctly? If it wasn’t, the wrong ing and application of any pesticide is long pants, a long-sleeved pesticide may have been used or applied at the wrong time. shirt, shoes with socks, and rubber gloves. A hat is needed if 2. Was the correct rate of pesticide application used? Lack of you are spraying tree foliage or where you may be exposed to calibration or faulty equipment can cause control failures. drift from above. 3. Was the application timed correctly? Sometimes the pests After using any pesticide, wash your hands and arms thor- are too large to be controlled by a pesticide or they’re in a oughly with soap and water. If you have been doing a lot of less susceptible stage. In other cases, the damage is already spraying or dusting, remove your clothes, take a shower, and done and killing the pest has no impact on the problem. put on clean clothes. Clothing worn while applying pesticides should be laundered separately from the family wash. After cleaning pesticide-contaminated clothing, the washer should Safety be run once without laundry but with detergent. Safe use of pesticides involves self-protection and knowl- edge of proper techniques for mixture, application, cleaning Know Symptoms of Pesticide Poisoning of equipment, storage, and disposal. You also need to be able It’s important to be aware of the early symptoms and signs of to recognize the symptoms of pesticide poisoning. pesticide poisoning. These symptoms are general and similar to Use safety precautions as described in this section and treat those of flu or heat stress. They include fatigue, headache, and all pesticides with respect, taking care to always follow label dizziness. Exposure to concentrated pesticides can also cause directions. blurred vision, excessive sweating and salivation, nausea and vomiting, and stomach cramps or diarrhea. Tips for Safe Handling and Mixing First-aid procedures vary somewhat depending upon the Here are some tips for safe handling and mixing of pesticides: pesticide, so see the pesticide label for instructions. In general, Wear rubber gloves and any other protective equipment, however, you want to stop the exposure and wash or flush the such as eye protection, required by the label. area to remove or dilute the pesticide. Keep children and pets away from the area where you are Specific information on poisons and chemicals is available mixing pesticides. from the Kentucky Regional Poison Center of Kosair Children’s Close container caps when you are finished using the Hospital, (800) 222-1222 and online at https://kypoisoncontrol. pesticide. com/. Do not leave containers unattended while applying pesticides. Keep a separate set of tools, including measuring spoons and Other Safety Issues cups and stirring paddles, for mixing and applying pesticides. Pesticides and the Environment Use plastic or metal items, not glass or wood. Open and mix pesticides outdoors or in a well-ventilated Pesticides can harm the environment if they are not used space. correctly. Most pesticides break down quickly and remain in the Mix only the amount of pesticide you will use. environment only briefly before being changed into harmless Have an absorbent material available to clean up a liquid spill, products. Some, however, break down slowly and stay in the such as cat litter (best), sawdust, or sweeping compound. environment for a long time. They can build up in some plants These materials can also be used to clean up other spills too, and in the bodies of animals and people. such as paints, solvents and fuels. Spread the absorbent on Responsible pesticide users know and follow good practices the spill, then sweep it up and put it into a heavy-duty plastic that achieve effective pest control with very little risk of envi- bag. Do not wash down spills with water. ronmental impact. Any material used to clean up the spill should be properly Anyone who uses a pesticide must ask the following disposed of, including a broom. questions: Small quantities of spilled homeowner pesticides and clean- How could this pesticide affect the immediate environment up materials may be placed into a heavy-duty plastic bag where it is being used? and securely sealed and disposed of in household trash. What is the danger that the pesticide will move out of the Immediately wash your hands and any exposed areas of your use site and cause environmental harm elsewhere? skin with soap and plenty of water. Shower if necessary. 11-6  Pesticides and Pesticide Safety CHAPTER 11 Off-Target Pesticides Apply insecticides when the air temperature is below 55°F; bees are less likely to be actively foraging then. Fine mists of herbicides can drift to nearby gardens or Use buffer strips between treated turf areas and flowering landscape plants and either injure them or leave unacceptable plants. residues. The natural enemies of pests can also be killed by Spot-treat infested areas rather than broadcasting pesticides. To protect beneficial insects, avoid excessive use applications. of insecticides—spray only when pest activity is increasing Whenever possible, use insecticides or formulations that are or high. Use selective products and spot-treat infested areas least toxic to bees. when possible. Life in streams or ponds can be contaminated by accidental Insecticides should be the last resort in managing insect spraying of ditches and waterways, runoff from sprayed land- pests. While we want to maintain the visual appeal of our scapes, or careless disposal of containers. If more than one yards and landscapes, most insects that feed on our flowers, pesticide will control the pest, choose the one that is the least ornamentals, and turf are not harmful to the plant. Low num- hazardous to the environment and most useful for the situation. bers and light to moderate damage should be tolerated, when practical. Both homeowner and commercial use of insecticides should involve careful, responsible, and prudent applications of How to Protect Pollinators From Pesticides compounds that are toxic to beneficial insects. Some pesticide Most people who are active in caring for their lawns and labels feature a “pollinator protection box” (or bee icon) that landscaped plants are aware of (and concerned about) the alerts applicators to specific use restrictions. decline of insect pollinators. Reasons for the diminishing numbers of honey bees include combinations of habitat loss, parasites (such as mites), diseases (including bacteria and Integrated Pest Management viruses), and pesticide exposure. Even sub-lethal exposures Integrated Pest Management (IPM) is an approach to pest to pesticides can negatively impact insect pollinators in many control that incorporates, in a coordinated strategy, techniques ways, such as negatively affecting their orientation and feeding including cultural practices, resistant varieties, use of natural behaviors and their ability to reproduce and increasing their enemies, and selective pesticide application. susceptibility to diseases. Key IPM principles include the following: The most important action to protect pollinators is to not Control a pest only when it is causing or is expected to cause apply pesticides to plants with open flowers. Encourage pol- more harm than is reasonable to accept. linators by establishing a variety of plants with different bloom Rather than to try to eradicate the pest, use a strategy that colors and shapes that flower at different times throughout will reduce the pest numbers to an acceptable level. the season. This will provide continuous food (nectar and Cause as little harm as possible to everything except the pest. pollen) sources and nesting habitats for many types of insect Be aware of weather conditions before and after application. pollinators. Weather can impact pest control. Rain can wash off pesticide Follow steps such as these to reduce exposing pollinators residues before the product can work, and poor growing to pesticides: conditions can prevent herbicides from being effective. Mow all grass areas before applying insecticides. This will remove most of the flowering plants and will reduce bee foraging in treated areas. 11-7 CHAPTER 11 Pesticides and Pesticide Safety Credits Compressed air sprayer: http://ag.arizona.edu Pesticide label: http://www.ag.ndsu.edu Revised 01-2024