Organic Insecticides – A Comprehensive Guide

Organic Insecticides

A Comprehensive Guide for Arkansas Farmers

Joseph M Hannan
Production Instructor
Center for Arkansas Farms and Food
09.10.2025
Edited by Luke Freeman

It’s September in Arkansas. Late summer is transitioning to early fall, but the insect pests are still going strong! Japanese beetles, cucumber beetles, cabbage moths, tomato fruit worms, Colorado potato beetles, leafhoppers, stink bugs, harlequin bugs, tarnished plant bugs, squash vine borers… you name it, we have it! This is also the time of year when row covers and insect netting become less effective due to the size of the crop, ongoing harvest, and lingering heat.

In short, this is the time of year when the best horticultural practices alone are no longer effective at maintaining clean product, and assistance is needed from organic insecticides. Fortunately, we have quite a few products available for certified organic production. However, they each have their own quirks and limitations, and no one product is a silver bullet. Soft-bodied insects, fliers, and worms can be effectively managed with a variety of organic products, while hard-bodied insects have the fewest options available and are more difficult to control organically.

Understanding Effective Pesticide Application

Before diving into specific products, it’s important to understand that for any pesticide to be effective, it must:

  • Be properly labeled for your intended use
  • Be applied at the correct rate with adequate water volume
  • Achieve good canopy penetration with medium to large droplet size
  • Be rotated according to IRAC (Insecticide Resistance Action Committee) codes to prevent resistance

Remember the difference between efficacy and effectiveness: efficacy means the product can kill the pest under ideal conditions, while effectiveness means it provides a real-world solution to your problem.

Pyganic or Pyrethrin

Pyganic and its generic pyrethrin alternatives are commonly found on organic farms for a couple of reasons: one, it actually works; and two, it works reasonably well. It has broad-spectrum control across a wide array of insects including aphids, whiteflies, beetles, and worms. It is very indiscriminate in what it kills, which is both a good and bad thing. Pyganic will kill insect pests, but it also kills beneficials. The other pitfall with Pyganic, like most other organic pesticides, is that it has no residual control. It breaks down in the environment and becomes inert very quickly. For Pyganic to truly be effective, you need a good sprayer that can really push product into the plant canopy and reach the top and bottom sides of the leaves. Pyganic needs to actually touch the insect during that spraying process. If an insect flies out of the field while you are spraying and then flies back into the field a few hours later, it will not be controlled. This is why a lot of people don’t think Pyganic is working for them. It is likely because they had poor coverage and didn’t get the insecticide into the plant canopy to reach the insects, or new ones flew into the field.

In efficacy trials, Pyganic often shows 75 to 85% efficacy across difficult-to-control pests. In general, it is less effective than Azera or Entrust against difficult-to-control insects and no more effective than soaps or oils against soft-bodied insects. In my opinion, it should be on your pesticide shelf but beware of its limitations.

To increase your effectiveness with Pyganic, and many other products, increase the gallons of water used. More water increases the likelihood of reaching the pest (at the downside of more water and time). The Pyganic 5.0 label calls for a minimum of 2 gallons of water per acre. Unless you have a very high-quality air-assisted sprayer, this simply isn’t enough water volume to be effective. Twenty-five gallons of water per acre at full crop canopy is much more appropriate with simple nozzle-type sprayers. For those with simple nozzle-type sprayers, adding fans to your sprayer can help agitate leaves and spread product into your plant canopy, though the reality of adding adequate electrical power to your tractor and the costs of fans is prohibitively expensive.

For hand-tool-scale fields, hand-pump pressure tank sprayers are going to be your worst tool for pest management (approximately $50). A battery- or gas-powered backpack sprayer (such as the Ryobi One+ 18v or 40v or Makita 18v backpack sprayers) will be better (approximately $250). But the best option would be an air-assisted sprayer such as the Stihl SR200 backpack sprayer because it includes a fan to blow and agitate the leaves (approximately $450-$500). If you are looking for a new sprayer, look for something with a fan or air assist for best performance if you can afford it.

If you are reaching for Pyganic, you likely are targeting a mobile insect, which means that spot spraying will be insufficient. Hard-shelled adult insects such as cucumber beetles, stink bugs, and harlequin bugs are difficult to control regardless. Also know that 100% control with one application is unlikely. When purchasing Pyganic, be sure to read the label and verify that it does not restrict commercial use. If the label states “not for commercial use” or similar, this means that it cannot be used on crops that are grown for sale. Bonide brand Pyganic is a prime example here.

Important rotation requirement: You are advised not to apply Pyganic twice in a row in the same field, per the label; however, you are not absolutely restricted from doing so. You should rotate to a different class of insecticide before you can spray Pyganic again. This could look like switching between Pyganic and Neem if making multiple applications to control a specific pest in the same field. Check for IRAC codes to ensure proper rotation.

Neem

Neem is a complex oil extract from the Neem tree. It contains azadirachtin + oils. It’s a broad-spectrum insecticide with fungicide claims, though I don’t know of anyone using it as a fungicide or any major trials verifying its fungicide efficacy. Like Pyganic, it controls a wide range of insects, has no residual control, and is a contact kill only. It must physically contact the pest you wish to control, so similar best practices as Pyganic are recommended for application. Because Neem is an oil, direct sunlight with high temperatures following application can cause some burning of the leaves. It is best used on cloudy days or during the evening to minimize risk of crop injury.

Reviewing efficacy trials, Neem, in my opinion, is rarely the right choice. It generally is less effective than Pyganic, Entrust, and Azera against difficult-to-control insects and no more effective than soaps and oils against soft-bodied insects. It may have a niche job somewhere, but due to its low broad efficacy and high cost, it doesn’t have a spot on my pesticide shelf.

Aza Direct

Aza Direct is the azadirachtin-only portion of neem oil. Everything else from the neem oil is removed. It works as a feeding inhibitor and repellent. It can have 24 to 72 hours of effectiveness under ideal conditions before it needs to be reapplied. While it technically has broad-spectrum control, Aza Direct has limited use cases since it doesn’t actually kill the insect pest. However, Kansas State researchers have found some positive effects against insect growth and development. I am undecided on how I feel about this product… I just don’t have enough data, so it does not currently sit on my pesticide shelf.

Azera

Azera is a premix of Aza Direct and Pyganic and makes an interesting product. It seems that the two chemicals work synergistically when mixed together in a tank and applied together. This is a case where 1+1 > 2. Azera consistently equals or outperforms Pyganic, Neem, and Entrust against difficult-to-control insects. For harlequin bugs, this is one of your options. You can tank mix your own Azera by mixing Pyganic and Aza Direct.

Valent/MGK, the former manufacturer of Azera, was purchased by Corteva (I believe) recently. There has been rebranding and relabeling of Azera the past year, and I am unsure if the product will be available for the 2026 season.

M-Pede

M-Pede is an insecticidal soap, which is derived from animal fats and plant oils. Soaps have broad-spectrum control but predominantly work on soft-bodied insects such as aphids, spider mites, and whiteflies. If you have a high tunnel, you should have M-Pede on your shelf. It is one of the most effective (considering cost and efficacy) options for these types of insect pests. As you might expect, soaps are contact-kill only and have no residual activity. However, most of the soft-bodied insects are not very mobile, which means that spot spraying is highly effective. If you are targeting aphids, spider mites, or whiteflies, keep in mind that soaps DO NOT kill eggs. You will need to make multiple repeat applications to control the new egg hatches. I generally recommend spot spraying every 2 or 3 days for 3 to 4 applications to catch all of the egg hatches. The nice thing is that this is just a localized spot spray, so there is minimal risk to nearby beneficials.

While soaps generally don’t have any efficacy against eggs, they do seem to have some control against harlequin bug eggs.

Horticultural Oil

Horticultural oil (and I am sticking to a generic name here because there are a TON of them) are lightweight mineral- or vegetable-oil-based products. They perform similarly to soaps in that they are broad spectrum, contact only, and work best on soft-bodied aphids, spider mites, and whiteflies. Like all oils, they can cause leaf burn under warm, sunny conditions—so apply on cloudy days or in the evening. Horticultural oil has a greater tendency to burn than soaps, which is why I don’t reach for it first. As with soaps, multiple applications of horticultural oil every few days may be needed to control aphids, spider mites, and whiteflies.

Occasionally soaps don’t work for people trying to manage soft-bodied insects. When that happens, I usually suggest horticultural oil and that seems to do the trick because it does have action against eggs.

Entrust

Entrust, otherwise known as spinosyn or Spinosad, is a very unique product and is the first one on our list that has residual activity, meaning it can keep actively killing insects for 3 to 5 days AND is at risk for resistance buildup.

Entrust provides very good control against caterpillars, flies, and beetles. It is considered fairly broad-spectrum, but not as much as Pyganic; and it has a fairly short reentry interval (REI) and pre-harvest interval (PHI). Because of these factors, Entrust is commonly used in fruit crops to control spotted wing drosophila, worms, and beetles that would normally infest ripening fruit. However, overuse of this product presents the risk of insect resistance. There are limitations to the number of times Entrust can be applied to a crop (typically 3 applications per year) and total amount of product that can be applied to mitigate this risk. It cannot be used twice without rotating to another product with a different mode of action. It is common to see an Entrust–Pyganic–Entrust rotation used for challenging pests on organic crops. Entrust is expensive, however, and should be used only with high-quality sprayers. It provides better control on caterpillars and flies than beetles, which remain challenging to control.

Recent efficacy trials show Entrust has efficacy against harlequin bugs. However, it is not labeled for use against them. Hopefully the label will get updated in light of new research and we will have a new tool against harlequin bugs!

Understanding REI and PHI

  • REI (Re-entry Interval): The time between application and when workers can safely re-enter the field
  • PHI (Pre-harvest Interval): The time between application and when crops can be harvested for sale

Bacillus thuringiensis (Bt)

Most everyone is familiar with the worm killer Dipel, the most common form of Bt. Bacillus thuringiensis kurstaki is one type of Bt, a bacteria-based insecticide. It is very effective at controlling caterpillars and has a few days of residual activity. Dipel is commonly used against tomato hornworm, tomato fruit worm, cabbage loopers, and other worms. If worm control is your intention, then BtK has the greatest efficacy and is the most cost-effective option. BtK, or Dipel, is a bit different than many other organic insecticides. Dipel must be ingested by the worm. Once ingested, the worm will stop eating and damaging the crop, though it may take some time for the worm to actually die.

Other forms of Bt include:

  • Bt israelensis: Primarily targeted towards mosquitos, fungus gnats, and blackflies—not a food crop product
  • Bt galleriae (BeetleGone and others): Primarily targeted towards beetles. Beetles are extremely difficult to control, organic or not, and field efficacy data remains limited.

Other Worm Killers

Helicovex and Hearken are newer products on the market that specifically target corn earworm/tomato fruitworm. These products are VERY targeted in only controlling that one pest! I don’t have much information on Hearken, but the University of Arkansas has good data on Helicovex. Helicovex works best when targeted towards small, recent egg-hatch worms. It does not work against larger, mature worms. And your application threshold levels are much lower than Dipel or conventional products. Essentially, the threshold for treatment is 1 with these products.

Hearken looks to be a virus that grows and spreads across a population and can be transmitted from adult moths to larvae. Both products look promising and are worth trying… I’m sure one or both will be used at CAFF next year.

Grandevo

Grandevo from Marrone Bio Innovations is a bacteria-based broad-spectrum insecticide that works as a repellent, anti-feeding agent, and reproduction reducer. While it shows efficacy under low pest pressure conditions, it tends to fail under high-pressure situations. This makes it more suitable as a preventative measure rather than a curative treatment.

Surround (Kaolin Clay)

Surround WP and similar kaolin clay products work as a protectant, anti-feeding agent, and suffocant. The clay creates a physical barrier on plants that deters insects. It needs to be reapplied after 0.5 to 1 inch of rainfall. This product is particularly useful in fruit production where the white residue can be washed off before sale.

Plant Extracts or Essential Oils

Plant extracts and essential oils can also be used for insect control. All essential oils have similar efficacy towards targeted insects as horticultural soaps and oils. They work best on soft-bodied insects. You can buy or make your own extracts for use as an insecticide. Plant extracts are largely unregulated with a few exceptions. Citronella, for example, is a commonly used repellent but is not allowed for use on food crops. You can see the full list of Active Ingredients Eligible for Minimum Risk Pesticide Products from the EPA online and whether or not they can be used on food crops.

If you are making your own essential oil extracts for use as a pesticide, the plants you are growing for extract should be grown using the same safe food production practices that you would follow for growing produce. Additionally, you must use clean water in your spray mix (city water or well water that has tested free of E. coli), and the active ingredients must be on the EPA’s list of chemicals exempt from pesticide registration.

Peppermint

Peppermint is primarily a repellent but may have some killing action against soft-bodied insects like aphids and spider mites. I often find peppermint mixed with rosemary or thyme, offering a synergistic effect in research reports and commercially available products. The combination often works better than either oil alone. It is an oil, so there is risk of burning; and it requires multiple applications like other oils for complete control. I see no value in using peppermint over commercially available soaps and oils from a cost or efficacy standpoint.

Rosemary

Rosemary works best on soft-bodied insects and, from talking to people who have used it, seems to be effective in both research trials and on-farm trials. Kemin Industries makes TetraCurb and now TetraCurb Max, which have rosemary oil as their active ingredient. I have found some other commercially available products that contain rosemary and thyme, but their labels did not include food crops. Efficacy and cost should be comparable to commercially available soaps and oils and perhaps marginally better. Rosemary is an interesting product as it is a renewably grown pesticide using mechanized planting, cultivation, and harvesting processes.

Summary

There are many effective options for soft-bodied insect control in organic fruit and vegetable production, many of which are soap- or oil-based products. However, there are very few organic options for hard-shelled insects such as cucumber beetles and harlequin bugs. Selecting the right product and using it correctly is critical for success, in addition to understanding that 100% control may not be feasible with organic insecticides under high pest pressure, especially when combating hard-bodied pests.

When planning your pest management strategy, remember to:

  • Choose the right product for your target pest
  • Apply with adequate water volume and proper equipment
  • Rotate products according to IRAC codes to prevent resistance
  • Time applications for optimal conditions (cloudy days for oils, warm days for Bt)
  • Accept that multiple applications may be necessary
  • Maintain realistic expectations—100% control is rarely achievable organically

The number of certified organic pest management tools is steadily increasing as certified organic market share increases. Many products available on the market today are not listed in this article, and that is not a slight against them. For the products not included in this article, I simply don’t have enough information on their efficacy or best practices on their use in Arkansas.

For more information on organic pest management practices, vendor lists, and additional resources, contact the Center for Arkansas Farms and Food or consult with your local extension service.