Organic berry production has unique challenges, one of them being managing insect pests with limited insecticide options, while continuing to rotate chemical classes to prevent insecticide resistance. In this article, we focus on the insecticide options available for organic production. However, organic insecticides will provide adequate control of insect pests if they are backed up by a solid IPM program. For a reminder of other IPM techniques to complement an organic spray program, please see our series published in 2017 in this newsletter (WFN, Volume 2, issues 3-9) on IPM topics including: monitoring, cultural control, host plant resistance, mating disruption, and biological control.
The table below lists some insecticides which are approved for organic production in Wisconsin, along with their IRAC (Insecticide Resistance Action Committee) chemical class code, re-entry interval (REI), pre-harvest interval (PHI), and efficacy ratings against some of the main insect pests of berry crops, including spotted wing drosophila, Japanese beetle, and tarnished plant bug. We do not provide efficacy for other insects, but these insecticides have efficacy against other insects as well. All of the following insecticides are registered for use on caneberries (raspberries and blackberries), strawberries, and blueberries in Wisconsin. Please refer to the latest Midwest Fruit Pest Management Guide for information about other insecticides and other fruit crops, and always read the label prior to use. This is not an exhaustive list and we do not endorse any products.
|Class (IRAC code)||Tradename||Active ingredient(s)||REI (hrs)||PHI (days)||Efficacy against spotted wing drosophila (SWD), Japanese beetle (JB), and tarnished plant bug (TPB)|
|Surround||Kaolin claay||4||0||SWD: n/a|
|DES-X||Insecticidal soap||12||0||SWD: n/a|
|Spinosyns (5)||Entrust SC||Spinosad||4||1||SWD: Excellent|
|Pyrethroids (3A)||Pyganic EC 1.4||Pyrethrin||12||when dry||SWD: Fair|
|Venerate XC||Burkholderia spp.||4||9||SWD: Fair|
|Isaria fumosorosea||4||0||SWD: n/a|
|Bacillus popilliae spores||varies||varies||SWD: n/a|
In general, organic insecticides fall into four IRAC classes: spinosyns, pyrethroids, Neem oils (Azadirachtins), and biologicals.
Spinosyns and Pyrethroids affect the nervous system of many species of insects. Both have low mammalian toxicity, except interestingly pyrethroids can be toxic to cats. However, they both do have non-target effects on beneficial insects and bees, and so should be used with caution and not be sprayed during bloom.
Azadirachtins are found naturally in the oil of the Neem tree (native to India and surrounding countries). As an insecticide, it works by interfering with the insects’ ability to molt (shed their skin), therefore preventing normal development. These insecticides also serve as repellents. They are considered to be safe to humans and other mammals, and to have minimal non-target effects on beneficial insects.
Biologicals are usually targeted to affect only the pest and its related species, and so are considered to be relatively environmentally safe. In many cases, biologicals can effectively help manage pests while maintaining healthy beneficial insect populations. However, they require careful timing to target the correct pest species at the life stage when it is most vulnerable to the insecticide, and are not effective against all pest species.
More information about organic berry production is available in Cornell University’s series on Organic Production and IPM Guides for raspberries and blackberries, strawberries, and blueberries as well as on our Wisconsin Fruit berry pages. Also, we have a new publication in collaboration with other universities on “Management recommendations for spotted wing drosophila in organic berry crops”.This article was posted in Insects.