All our islands have been suffering from these insects since 2019. In reading through all the information we have to date there are a few takeaways for managing Avocado Lace Bugs (ALB) on your trees.
In most cases, unless your tree is completely covered with the insects your tree should be alright. If your trees are not tall we suggest you spray the underside of your Avocado leaves with a garden hose to knock the insects off the leaves. If your trees are taller you can try spraying with your garden hose but you may need to use a ladder to reach these leaves.
If you find spraying water does not remove all the insects you might need to purchase one of the pesticides or organic options noted on page two in the Avocado Lace Bug IP-50 document. (We’ve included the information below)
Pesticides
Insecticidal soaps (e.g. M-Pede ®, Safer Soap®) and insecticidal oils (e.g. Green Light®, SunSpray®) can provide effective suppression of lace bugs, if applied carefully to ensure good coverage. These products need to cover the target insects in order to be effective. While truly a biological control agent, Beauveria bassiana, an insect pathogenic fungus, is a registered insecticide; applications of Beauveria bassiana (BotaniGard®, Mycotrol®) have been suggested to provide temporary suppression of lace bugs – again, with the caveat that effective coverage under leaves must be achieved. These products have minimal negative impacts on non-target insects.
Synthetic contact insecticides labelled for use on avocado will likely also cause lace bug mortality. Systemic products (e.g., imidacloprid) will likely provide the most effective suppression of avocado lace bugs. Be aware that these products may have undesirable non-target impacts on beneficial insects.
Biological Control
There are no known specialist natural enemies that will act as biological control agents in Hawai‘i. In the place of origin of the avocado lace bug (the Caribbean), there are two known egg parasitoids, and the lace bug nymphs are attacked by predatory thrips there.
Other known natural enemies are generalist predators, such as lacewing larvae (different from lace bugs!), lady beetles, and predacious mites. Many of these generalist predators are present in Hawai‘i (see “Links to other resources”) and may provide some level of suppression of the lace bugs under suitable conditions. The growth and persistence of generalist predator populations can be encouraged by providing habitat, such as flowering plants that provide secondary food resources like pollen and nectar, and by avoiding the use of broad-spectrum insecticides.
In addition, we’re including a statewide seminar video from January 2023 that details testing on a number of pesticides and offers a number of tips in working to manage ALB if you have a number of Avocado trees.
If you have more than a couple of trees that are suffering from ALB this 80 minute video is worth your time.
Our takeaways from this video are:
- To prevent damage, start treatment as soon as you find your first sighting.
- You will need more than one long term pesticide solution to manage the ALB issues. Target three pesticides.
- Do not use any of these pesticides when your tree is flowering. You will lose an entire season if this happens.
- There are only a couple ground based solutions for treating ALB. All will impact insects living in or on the ground when treating you tree.
- When you first start treating your tree you will need to spray every two to four weeks, dependent on your pesticide selection.
- If your tree is taller than 15-20 feet you will not be able to spray any of these pesticides without impacting your neighbors. Be careful.
- The video recommends that if your tree is taller than 20 feet your should cut to this height. Ground based pesticides have not been tested to verify specific height coverage.
- You can mulch the avocado leaves if they’ve fallen off your tree. The insect is gone from your leaf by this time.
- In their studies, the San Miguel Avocado seemed to do best with resistance to the ALB.
This group will be starting phase II of their testing sometime in 2024.
We’ve included a few informational web sites and documents that walk you through what you need to do to eliminate these pest.
UC Riverside Link – https://www2.ipm.ucanr.edu/agriculture/avocado/avocado-lace-bug/
Here is a link to an article from the Big Island Invasive Committee – https://www.biisc.org/pest/avocado-lacebug/
We’ve attached an article from UH that describes way to help eliminate the lace bugs – Avocado-Lace-Bugs-IP-50
*Please note that any pesticide applications must be made in accordance with label requirements (US EPA and HI State). The mention of any product here is not a CTAHR or UH endorsement of that product.
JRS – 3.28.23
