New Avocado Pest Identified on Big Island

The avocado lace bug is known to damage the leaves of avocado trees, resulting in a reduction of yield. PC: HDOA

A new avocado pest has been identified and confirmed on the Big Island.

Hawai`i Department of Agriculture entomologists announced Tuesday that the avocado lace bug (Pseudacysta perseae) was first detected at Pearl City, O‘ahu, in December 2019. It was later discovered on Hawai‘i Island and from plants in retail outlets on Maui that were destroyed or treated.

The University of Hawai‘i College of Tropical Agriculture and Human Resources – Cooperative Extension Service (CTAHR-CES) aided HDOA in the discovery and identification of the pest.

Ken Love, president of Hawai‘i Tropical Fruit Growers, said the lace bug was a topic of conversation at the annual Avocado Festival over the weekend. So far, the lace bug has proven to be more of a problem on the east side of the Big Island, Love said. However, he expects that will soon change.

“Everything else that’s started on the east side has ended up over here,” said Love, who operates a farm in South Kona.

The avocado lace bug feeds on the leaves of avocado plants and extracts nutrients from foliage, causing gradual destruction of the leaves, HDOA explained. It does not feed on the fruit itself but causes green to yellowish blotches on the leaves. Heavily damaged leaves become dry, may curl, drop prematurely and may cause a reduction in fruit yields.

Adult lace bugs are about 2 millimeters long with black heads, mostly black bodies and a black stripe across the width of their lacy wings. Immature avocado lace bugs can range in color from reddish to dark brown to black, depending on their life stage. The eggs are black and look like specks of excrement, HDOA said. They may be found in clusters on the undersides of the leaves.

CTAHR-CES extension agents are currently working to determine effective treatment plans for various levels of infestations in Hawai`i.

The avocado lace bug was described in Florida in the early 1900s and has spread through the southeastern U.S. and into California. It is also found in the Caribbean, Central and South America, and Portugal. It has not been determined how the lace bug was introduced in Hawai‘i.

Possible infestations should be reported to HDOA’s Plant Pest Control Branch, which can be reached at hdoa.ppc@hawaii.gov. Photos of the damage to avocado plants are also helpful in identifying the cause, the department said.

To view the avocado lace bug flyer and field guide, go online.