Insect Control: Soaps and Detergents by W.S. Cranshaw 1 Quick Facts... Soaps can be used to control a wide range of plant pests. Small, soft-bodied arthropods such as aphids, mealybugs, psyllids and spider mites are most susceptible to soaps. The ease of use, safety and selective action of soaps appeal to many people. Limitations of soaps include the need to wet the insect during application, absence of any residual effectiveness, and potential to damage some plants. Soaps or detergents used for control of insects are applied as dilute sprays, mixed with water to produce a concentration of about 2 percent. Soaps have been used to control insects for more than 200 years. Recently, there has been increased interest in and use of these products. This change is due to a better understanding of how to use soaps most effectively and a desire to try insecticides that are easier and safer to use than many currently available alternatives. How soaps and detergents kill insects is still poorly understood. In most cases, control results from disruption of the cell membranes of the insect. Soaps and detergents may also remove the protective waxes that cover the insect, causing death through excess loss of water. Soap-Detergent Sprays Soaps and detergents act strictly as contact insecticides, with no residual effect. To be effective, sprays must be applied directly to and thoroughly cover the insect. Several insecticidal soaps are distributed for control of insects and mites. Available under a variety of trade names, the active ingredient of all is potassium salt of fatty acids. Soaps are chemically similar to liquid hand soaps. However, there are many features of commercial insecticidal soap products that distinguish them from the dishwashing liquids or soaps that are sometimes substituted. Insecticidal soaps sold for control of insects: are selected to control insects; are selected to minimize potential plant injury; and are of consistent manufacture. Some household soaps and detergents also make effective insecticides. In particular, certain brands of hand soaps and liquid dishwashing detergents can be effective for this purpose. They are also substantially less expensive. However, there is increased risk of plant injury with these products. They are not designed for use on plants. Dry dish soaps and all clothes-washing detergents are too harsh to be used on plants. Also, many soaps and detergents are poor insecticides. Identifying safe and effective soap-detergent combinations for insect control requires experimentation. Regardless of what product is used, soap-detergent sprays are always applied diluted with water, typically at a concentration of around 2 to 3 percent (Table 1). Susceptible Insects Most research with insecticidal soaps and detergents has involved control of plant pests. In general, these sprays are effective against most small, soft-bodied arthropods, such as aphids, young scales, whiteflies, psyllids, mealybugs, and spider mites. Larger insects, such as caterpillars, sawflies and beetle larvae, generally are immune to soap sprays. However, a few large insects, including boxelder bugs and Japanese beetles, are susceptible. Insecticidal soaps are considered selective insecticides because of their minimal adverse effects on other organisms. Lady beetles, green lacewings, pollinating bees and most other beneficial insects are not very susceptible to soap sprays. Predatory mites, often important in control of spider mites, are an exception: a beneficial group of organisms easily killed by soaps. Application One of the most serious potential drawbacks to the use of soap-detergent sprays is their potential to cause plant injury -- their phytotoxicity. Certain plants are sensitive to these sprays and may be seriously injured. For example, most commercial insecticidal soaps list plants such as hawthorn, sweet pea, cherries and plum as being sensitive to soaps. Portulaca and certain tomato varieties also are sometimes damaged by insecticidal soaps. The risk of plant damage is greater with homemade preparations of household soaps or detergents. When in doubt, test soap-detergent sprays for phytotoxicity problems on a small area a day or two before an extensive area is treated. Plant injury can be reduced by using sprays that are diluted more than the 2 to 3 percent suggested on label instructions. To reduce leaf injury, wash plants within a couple of hours after the application. Limiting the number of soap applications can also be important, as leaf damage can accumulate with repeated exposure. However, because of the short residual action, repeat applications may be needed at relatively short intervals (four to seven days) to control certain pests, such as spider mites and scale crawlers. Also, application must be thorough and completely wet the pest. This usually means spraying undersides of leaves and other protected sites. Insects that cannot be completely wetted, such as aphids within curled leaves, will not be controlled. Environmental factors also can affect use of soaps. In particular, soaps (but not synthetic detergents) are affected by the presence of minerals found in hard water, which results in chemical changes producing insoluble soaps (soap scum). Control decreases if hard-water sources are used. Insecticidal soaps may also be more effective if drying is not overly rapid, such as early or late in the day. Soaps and detergents can offer a relatively safe and easy means to control many insect pests. As with all pesticides, however, there are limitations and hazards associated with their use. Understand these limitations, and carefully follow all label instructions. Table 1: Approximate mix to produce various dilute soap sprays. Percent dilution desired Approximate amount of soap to add to water to produce: Gallon Quart Pint 1 2 1/2 Tbsp (-) 2 tsp (+) 1 tsp (+) 2 5 Tbsp (-) 4 tsp (+) 2 tsp (+) 3 8 Tbsp (+) 2 Tbsp (+) 1 Tbsp (+) 4 10 Tbsp (-) 2 1/2 Tbsp (+) 4 tsp (+) (+) Will produce a solution of slightly higher concentration than indicated. (-) Will produce a solution of slightly lower concentration than indicated. 1Colorado State University Extension entomologist and professor, bioagricultural sciences and pest management. 12/96. Reviewed 3/08. Colorado State University, U.S. Department of Agriculture and Colorado counties cooperating. CSU Extension programs are available to all without discrimination. No endorsement of products mentioned is intended nor is criticism implied of products not mentioned. Go to top of this page. Updated Friday, August 03, 2012

YouÂve got that right, CatNTree, it is confusing! YouÂre the first one that mentioned it looks like blight. I feel strongly we donÂt have any spider mites as IÂve checked foliage and cannot see any signs of pests. We amended the soil last year only when we created the bed adding Oma-Gro, a couple bags of sheep doo doo and some worm castings. Nothing this year because I felt it was rich enough soil. I did not fertilize when planting and have only used a foliar spray once which consisted of Neptune fish emulsion/seaweed kelp dissolved in water (per package directions) and sprayed onto the foliage. I think it was about an eighth cup emulsion to a gallon of water but would have to check to be sure. Goose Creek has no webbing. None of the plants do in fact I watered them by hand yesterday morning and kept thinking how odd that they look so healthy above the brown dead leaves and I think they may even look a bit improved except for the dead brown stuff because there is such strong green growth from the tops. They are really huge plants, most of them. I also noticed a lot more green balls than IÂd thought had already set on and was pretty happy about that especially since Carolyn told me with these high temps weÂve been having the fruit set doesnÂt happen. That was good info as I didnÂt know it. farkee  the truckload of Oma-Gro was for this bed only. It was my neighborÂs pickup truck and was a cheaper way of buying it than by the bag which can be expensive. We tilled the soil first as deeply as possible and then added the Oma-Gro to the top few inches and tilled it again. As for drainage I suppose that could be a consideration because this garden sits at the bottom of a hill in my back yard and we didnÂt think about sitting water there after a torrential rain. That hasnÂt happened often but it did for a few days early on because we got pelted. I still think it drains pretty well for its location and generally the soil even with the clay content is crumbly. Everywhere else weÂve planted things the drainage is quite good but I will check on that. We have started to get the dead foliage off and they sure look funny. I also noticed while watering that the stems (stalks?) all look very healthy with no discoloration or spotting so IÂm still stumped. At the risk of sounding like an idiot could this at all be due to not enough water? I mean, if it is not soaking in evenly throughout the bed would the plants look like this if they didn't get enough water?

Still doubt you actually have read many of my posts. If you had you would see my tenants actually recomend me to potential tenants. When I show vacant apartments I give out applications and references from other tenants. Every year tenants fill out surveys anonymously. I have also posted about my wedding and having many past and current tenants attend. We even took a few group pictures of past neighbors. I know I come of as insensitive to many posters. I actually agree with many of the posts but like to show other points of view to get people thinking. I have been a member of multiple boards, (buisness, non profit, and government) I would many times argue for the other side and still vote the majority, just wanting people to understand the entire issue. To many times everything is blammed on the landlord. People need to see things from the LL point of view. What are they going to do if they move out to a house? Someone vandalizes their car, breaks into their house, peoples pets use their yard, loud neighbors next door, etc. On their own they won't be able to call the LL! I rarely have many of the problems posted here because I let my tenants know up front I am a very strict landlord. That is obviously what many tenants want. Someone that will crack down on bad neighbors, and keep the building quiet. Besides how much fun with this forum be if everyone just patted each others back and agreed? Also no one HAS to do anything including renting from me. I learned a long time ago their are no needs only wants. This includes living.

I dont think anyone doubts for a minute that there are some really sick and twisted people out there who do prey on children. The problem with this type of allegation though is that it's very hard to give someone the benefit of the doubt, what if you're wrong? so once an allegation has been made the person (usually a man) is branded and everyone will assume he is guilty and it can take everything from them even if they are innocent. But on the flip side there are women who do this, what better way to punish a man than to see his world crumble, to lose visitation to his kids, and to have everyone think he is scum. I think there is a bias in society and the legal system that feels if the allegation is made it must be true, but there needs to be much more scrutiny of these allegations and everyone involved (not just the accused) to try and weed out the false claims from real victims, and there have been studies done that show young children especially are very open to suggestion and an idea or an event can be planted in their heads and they will recount the incident with total belief that it happened, that's how suggestable they are and some people use children as pawns to make these type of allegations when they never happened. If a man is truly guilty of child abuse I'll be the first to suggest they should string him up and cut off his privates, but a small number of woman do use this as a way to get back at someone or punish them for other things and that is the really sad part about it. I mean, when did putting sunscreen on a child become sexual abuse? when did it become a crime for a man to hug his daughter, or his neice, or the child of a good friend, it's all so screwed up