Instructions for making homemade mixtures to control pests are easy to find online and in social media, and it's tempting to make your own home remedy when pests invade. Doing so may seem like a natural, organic, and non-chemical solution, but did you know that what you are mixing is considered a pesticide? A pesticide is any mixture used to kill, destroy, repel, or mitigate a pest.

Pesticide mixtures of household ingredients like dish soap, garlic, and vinegar (Figure 1) may seem harmless and safer than storebought formulated pesticides, but they can actually pose unrealized risks.

What is the concern with homemade pesticides?

Figure 1. Pesticides made from household ingredients lack the details needed to safely and effectively control pests. (Credit: B Messenger-Sikes)

For example, some online sources describe making a homemade insecticide from the tobacco leaves found in cigarettes and tout it as “natural” or “organic.” While cigarettes are readily available for purchase, the resulting concoction (a pesticide) made from tobacco is extremely concentrated and highly poisonous to humans and pets. There are many additives used in producing products such as cigarettes, soaps, or detergents and these ingredients are not always known to the consumer.

Another concern is the potential hazard created during the mixing and making of home remedies. Even while natural, some ingredients become more toxic during the process of cooking the mixture, which may concentrate the ingredients and increase risks of harmful health side effects due to inhalation of fumes or contact with skin.

No instructions for use

Commercially available pesticides are required by law to have a label with instructions on use, mixing, storage, and first aid. Home remedies don't have instructions for specific dilution or use rates, nor do they identify how often mixtures should be applied. Home remedies also contain no guidance about wearing protective equipment like gloves or how to properly store the mixture.

Homemade mixtures are stored in containers that are either not labelled with what's inside or lack the required label information registered pesticides contain. Each year, poison control centers report poisonings of children and adults from drinking pesticides that have been stored in food or drink containers. Without a label and knowledge of how a mixture can affect people when exposed, first aid information isn't available. To prevent accidental poisoning, pesticides should never be mixed or stored in food or drink containers even if the container is marked.

Are home remedies effective?

Because homemade pesticides vary greatly in their makeup and are not tested through rigorous research studies, there is no data to support whether they consistently control targeted pests. Unlike commercial pesticides that must show their efficacy data before being registered, homemade remedies lack scientific studies to show that they are effective.

Applying ineffective homemade pesticides can make pest problems worse, may not control the pest, could be harmful to the plant, or contaminate waterways. In addition, a homemade pesticide sprayed in the garden may kill the “good bugs” as well as the targeted pest insects. Many commercial pesticides are formulated to work only on specific pests or groups of pests.

Many home remedies specify using dish soap mixed with other ingredients to kill insects, plant diseases, or weeds. Dish soap, which is a powerful detergent, can injure desirable plants by stripping the waxy layer off the leaves. Commercially available insecticidal, fungicidal, and herbicidal soaps, which are registered pesticides, are highly effective against the targeted pest and will not damage plants when used correctly. These products cannot be made at home with common household ingredients.

Are home remedies legal?

The U.S. Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) covers the use of homemade pesticides. According to FIFRA, in order to legally apply a material as a pesticide it must be either registered with the Environmental Protection Agency (EPA) or be exempt from registration. There is a list of active ingredients (the part of a pesticide that affects the pest) that can be used in pesticide products without requiring registration; these are called minimum risk or 25(b) products) The active ingredient list allows the use of single chemicals, like sodium lauryl sulfate (found in soap), as unregistered pesticides, but does not include commercial products like dish soap that may contain other ingredients, such as viscosity modifiers, preservatives, and pH adjusters.

Alternatives to pesticides

Many pests in the home and garden can be managed without pesticides. In a garden, grow plants suited to the environment and keep them healthy with proper irrigation and fertilization. Weeds can be controlled by hand-pulling, mulching, or weeding tools. For more information, see the UC IPM Home and Garden pages.

[Original article published in the Spring 2021 issue of the Retail Newsletter.]

While we continue to spend more time than usual indoors, you may have noticed a few unexpected (and perhaps unwanted) co-occupants like ants, cockroaches, or mice. Luckily, UC IPM has a series of fact sheets called Pest Notes to help you identify and manage hundreds of different pests in and around the home, only a portion of which might come indoors.

Any room in the home can attract and harbor indoor pests including kitchens, pantries, bathrooms, closets, storage areas, or other living spaces. Prevent and reduce indoor pest problems by cleaning and decluttering indoor spaces. This removes access to food, water, and shelter for pests such as ants, carpet beetles, rodents, and pantry insects. Find out where the pests are entering your home and prevent them from getting in. Keep reading for tips that will help limit potential infestations.

Kitchen and Pantries

Figure 1. Confused flour beetle (Credit: Clemson University)

Kitchens and pantries can provide abundant food and water for pests such as cockroaches, ants, meal moths, and pantry beetles (Figure 1). Be sure to wipe down countertops regularly, clean up grease deposits near cooking surfaces, clean off pantry shelves, and keep stored food in tightly sealed containers to reduce or eliminate these food sources for pests. Also, clean up spilled food and wash dirty dishes daily. Mop and vacuum floors to remove food and debris. Use sticky traps or pheromone traps to monitor and detect insects such as cockroaches and pantry pests and to help manage flying pests such as house flies and vinegar flies.

 

Living Spaces and Closets

Figure 2. Larva of furniture carpet beetle. (Credit: Jack Kelly Clark)

In living rooms, bedrooms, and closets, vacuum floors (especially along baseboards) and beneath furniture to reduce or prevent infestations of carpet beetles (Figure 2), clothes moths, fleas, bed bugs, and other pests. Reduce clutter to remove hiding places and make pest infestations easier to spot. Launder bedding, blankets, cushion covers and other washable articles to kill clothes moths, bed bugs, and carpet beetles. For bed bug or head lice infestations, be sure to wash and dry bedding and infested items at the hottest setting the fabric will permit. If items infested with head lice cannot be laundered, place them in a plastic bag and freeze for 48 hours.

Storage Areas

Garages, basements, attics, and other storage spaces can also attract unwanted pests. When possible, seal cracks and openings in foundations and around doors, windows, pipes, wires, and vents to reduce access to these areas by rats, mice, or raccoons. Use snap traps to control rats and mice indoors. Organize belongings in airtight containers such as plastic bins to keep out carpet beetles, mice, and silverfish. Store bins off the floor and away from walls to reduce clutter in storage areas.

Houseplants

Houseplants may be attacked by pests that are typically found outdoors including scale insects, mites, mealybugs, whiteflies, or fungus gnats. However, indoor management of these pests can differ from methods recommended for outdoor plants. Houseplant leaves and stems can be washed with water to remove soft bodied insects and mites. Use sticky traps to reduce fungus gnat populations by trapping adult gnats and adjust your watering. Pesticides such as insecticidal soap or horticultural oil may help control some of these pests but be sure products are labeled for indoor use on the houseplant species and against the pest you have identified. See the recently published Pest Notes: Houseplant Problems for more information.

Found a spider? Before you squish it, remember that spiders are predators which are beneficial and help control other pests around the home. If you are comfortable, let the spider be or capture and release it outside. See this video on how to do it.

Another visitor you might spot is a house centipede, but these invertebrates are also beneficial and do not damage plants or household items.

Wherever you may find pests in the home, use integrated pest management (IPM) to solve your specific pest problem. The combination of science-based methods suggested above will help exclude and manage pests so you can reduce any undesired co-occupants.

You can find much more information about all the pests mentioned in this article in the UC IPM Pest Notes publications located in the Household Pests section online.

[Original article published in the Winter 2020 issue of the Retail Newsletter.]

Pomegranate leaves and fruit covered in sooty mold (Credit: D Carroll)

Sooty mold is a black fungal growth that looks like a layer of soot covering the leaves of a plant or a sidewalk. The aptly named disease is common in gardens and landscapes, appearing wherever a large infestation of plant-sucking insects are found. Sooty mold grows on honeydew, a sticky substance excreted by plant-sucking insects.

While sooty mold doesn't actually damage plants or other surfaces, a thick growth of the fungus can block light to plant leaves, reducing photosynthesis. This can lead to stunted growth and premature leaf drop.

The key to reducing sooty mold is management of honeydew-producing insects, and ants. For specific tips on how to do achieve this, see the newly revised Pest Notes: Sooty Mold updated by Karey Windbiel-Rojas and Belinda Messenger-Sikes of the UC Statewide IPM Program.

Centipedes and millipedes are most often seen in yards and gardens, sometimes finding their way into houses. They are not insects, but they belong to the same group in the animal kingdom as insects and crustaceans.

While centipedes have 1 pair of legs per body segment, millipedes have 2 or 4 pairs of legs per body segment. Centipedes move more quickly than millipedes and are more prone to biting.

A centipede (above) and millipede side by side. (Credit: Jack Kelly Clark)

Learn more about these many-legged arthropods in our recently updated Pest Notes: Centipedes and Millipedes revised and reorganized by Karey Windbiel-Rojas of the UC Statewide IPM Program.