Location: Tropical Crop and Commodity Protection Research
Project Number: 2040-22430-027-056-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 1, 2024
End Date: Jul 31, 2027
Objective:
Avocado lace bug (ALB), Pseudacysta perseae, is a phloem-feeding insect pest of avocado trees and is invasive to California, Florida, and Hawai’i. Feeding by ALB nymphs leads to the accumulation of necrotic leaf spots resulting in defoliation and sunburnt, underdeveloped avocado fruit. Successive defoliation events from infested trees have been associated with a decrease in overall fruit yield. However, it is unclear how much infestation is required, and how many defoliation events must occur, for yield effects to justify the costs of management. For avocado growers in Hawai’i, this ambiguity has led to the inefficient use of various pesticide management programs and has resulted in further economic losses. The research objective of this project is to develop ALB economic threshold models based on cumulative ALB nymph abundance. Initiating management at varying thresholds of cumulative abundance, will lead to researchers being able to determine what level of ALB damage management should begin to minimize economic loss.
Approach:
Various abundance thresholds will be used to investigate the efficacy of systemic insecticide applications on the number and timing of defoliation events between harvest. The effects of these thresholds on yield will be examimed through fruit quantity and marketability. From these results, economic threshold models will be developed for two separate management programs utilizing nymph abundance or leaf necrosis-equivalent thresholds. Stakeholder and grower knowledge of avacado lace bug (ALB) management will be improved by (a) Conducting demonstrations of leaf necrosis monitoring on-farm, (b) Creating extension documentation, (c) Summarizing findings at grower meetings, and (d) Creating videos showing leaf necrosis monitoring and thresholds. It is anticipated that the results of this project will decrease yield loss for avocado growers while increasing ALB management sustainability by reducing the total number of insecticide applications required on an annual basis. The management tools developed from this project will be highly valuable to stakeholders throughout the Pacific-Western Region in California and Hawaii, but to avocado growers in other areas of the USA affected by ALB, such as Florida, Texas, Puerto Rico, and international regions of U.S. economic agricultural interest such as Mexico.