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Avocado Lace Bug Management

Posted on Jun. 28, 2024  /  Plant Pests, Edible Landscapes  /  Subscribe 0

By: Hannah Lutgen and Rosemary Gutierrez-Coarite

The Avocado Lace Bug, Pseudacysta perseae (Heidemann), is a new invasive pest of avocado in Hawaii. It has been found attacking avocado trees on multiple islands since December 2019.  

Description and Life Cycle

Adult avocado lace bugs measure about 2 mm in length, their body is black with yellow legs, wings, and antennae. The eggs are often covered with black, tar-like globs of excrement. After about 5 molts, nymphs mature into adults and are visible to the naked eye. All of the life stages of this pest including the adults, eggs, and nymphs live in colonies on the underside of avocado leaves. The avocado lace bug completes its life cycle in about 3 weeks during warm weather and it could take several months when temperatures are cool. The avocado lace bug has several generations per year in Hawaii.

Figure 1. Colonies of avocado lace bug on the underside of the leaf.

Figure 2. The adult stage of an Avocado Lace Bug with wings.

Damage

Avocado lace bugs feed by sucking sap on the underside of leaves. Feeding activity from a colony of lace bugs causes yellowish blotches on leaf surfaces and highly damaged leaves become dry and drop prematurely. Severe infestations result in sunburned limbs and fruits when leaves fall from trees. Tree defoliation may reduce subsequent fruit yields.

Figure 3-4. Yellow patches on leaves caused by Avocado Lace Bug feeding activity.

Management

Maintaining tree and soil health is essential to boosting a plant's immunity to pests. To keep avocado trees healthy, consider improving soil drainage, maintaining a thick layer of organic matter, providing adequate irrigation, and applying amendments or nutrients to the trees as needed.

A rotation of different pesticides may treat high infestations of avocado lace bugs. Conventional insecticides including Admire Pro, Sivanto Prime, and Malathion, and organic insecticides such as Pyganic, insecticidal soaps, azadirachtin, and Ecotec may control these pests if applied correctly. These organic and conventional insecticides are effective and can be used in a rotation by applying contact insecticides every two weeks and systemic insecticides once a month. For more information, please contact your local extension office.  Contact insecticides must directly touch the insect to be effective. Therefore, apply contact insecticides to thoroughly coat the underside of the leaves where avocado lace bugs feed and reproduce to suppress this target pest. Systemic insecticides are translocated and move within the plant (commonly used for tall trees where complete foliar applications are not feasible). 

Table 1. Pesticides labeled for use on Avocado in the State of Hawaii.

*=may negatively affect beneficial insects, pollinators, aquatic organisms, and water quality. Be aware that these products may have undesirable non-target impacts on beneficial insects

Disclaimer:

Mention of a trademark or proprietary name does not constitute an endorsement, guarantee, or warranty by the University of Hawai‘i Cooperative Extension Service or its employees and does not imply recommendation to the exclusion of other suitable products. Before applying any pesticide, applicators must determine if the product under consideration is correct for the intended use site. Always read the container/package label to determine if the intended use site is included on the label. READ AND FOLLOW LABEL INSTRUCTIONS BEFORE PURCHASING AND USING ANY PESTICIDE PRODUCT.

Rosemary Gutierrez-Coarite is the Edible Crops Extension Agent in the Department of Tropical Plant and Soil Sciences for Maui County. Her program focuses on integrated pest management, vegetable crop improvement, soil nutrient management, and agricultural best management practices. Her BS degree is in agriculture from Bolivian Catholic University, MS in Horticulture and Ph.D. in Entomology both from South Dakota State University.  

Hannah Lutgen, Maui County Landscape and Floriculture Extension Faculty Member, University of Hawai‘i at Mānoa, College of Tropical Agriculture and Human Resources.

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