Amy Tsuneyoshi
Hawai‘i Herald Columnist
If you have an avocado tree, I’m sure you have noticed the leaves with yellow and brown splotches. When you flip over the leaves, you’ll find the culprits causing the damage hiding underneath. This is the avocado lace bug (pseudacysta perseae), which was first reported in December 2019 in the Pearl City area. Since then, it has been reported across the state with the possible exception of Moloka‘i and Lana‘i.
Avocado lace bugs lay their eggs on the underside of the leaves, which are tiny black dots covered in their feces. If you notice a leaf with yellow or brown patches, flip it over to see if the insects are present. The eggs, nymphs and adults are tiny but visible without a magnifying glass. The adults have orange and black markings. The avocado lace bug is reported to have a 22-day life cycle from egg to adult.
I have an avocado tree in my yard that just finish producing fruits for this season. I trim back the taller branches each year as regular maintenance and so I can harvest fruits easily next season. Based on my observations since 2019, when I first saw the avocado lace bug on my tree, my plant has been able to produce flower and fruits despite the presence of this pest. The insect population fluctuates over the year and there will be periods where I won’t see that pest damage. Anecdotally, I have seen meijiro (zosterops japonicus) hopping along the branches pecking at the leaves, perhaps eating this pest.
I have a high threshold on acceptable damage on my plants before I resort to treatment. So, other than an occasional short, sharp spray of water from the nozzle to shoot off the pests while I’m watering my plants, I typically let the beneficial insects do their thing to keep pest populations under control. If you have a lower tolerance for pests and damage they cause, there are chemical options available. Just remember to read the chemical label carefully. Make sure the chemical is safe to use on avocado trees/fruit trees and know what precautions to take while using it. Follow all label directions. It is the law. If in doubt, you can contact the master gardener hotline on your island for specific advice.
Helpful links for more information:
- cms.ctahr.hawaii.edu/uhmgpd
- ctahr.hawaii.edu/oc/freepubs/pdf/IP-50.pdf
- hdoa.hawaii.gov/pi/files/2022/05/NPA-20-01-Avocado-lace-bug-5.11.2022.pdf
- hdoa.hawaii.gov/pi/files/2020/01/avocado-lace-bug-field-ID-photo-guide-1-15-2020.pdf
