Developing near and long-term management strategies for Lebbeck mealybug (Nipaecoccus viridis) in Florida citrus

Developing near and long-term management strategies for Lebbeck mealybug (Nipaecoccus viridis) in Florida citrus

Report Date: 09/12/2022
Project: 20-002C   Year: 2022
Category: Other
Author: Lauren Diepenbrock
Sponsor: Citrus Research and Development Foundation

Note: postdoctoral researcher previously working on this project for a faculty position left in May and the new hire started in mid August, so some objectives are behind where we would like to be. I. Research progress June 2022-August 20221. Near term field management(a) Develop methods to time management actionsIn the previous report, I discussed developing a relative scouting method for lebbeck mealybug detection. To determine if we could use an element of host attraction to monitor for lebbeck mealybugs, we induced damage to infested trees on peripheral limbs and wrapped these locations in corrugated cardboard. All damage “traps” were paired with undamaged limbs in similar locations on infested trees. After 2 weeks, we counted more juvenile lebbeck mealybugs in the damaged locations than in other traps. We now suspect that we may be able to use the odors produced by trees in response to damage to attract mealybugs.    To move this forward, we are identifying odors associated with various tree parts (mature leaves, flush, flower buds, and various stages of fruit, damage) to determine what odors are common to the two things we suspect that the mealybugs are attracted to from our work so far: immature/setting fruit and damage. Once we complete the analysis of the odors, we will work on determining what odor blends may be used as an attractant using lab studies. (b) Expand laboratory insecticide and adjuvant screening.No new data to report (c) Evaluate promising materials in open grove settingSpray trials are currently underway to determine optimal insecticides for managing lebbeck mealybug. While we are confident that early season control is key to protecting young trees, populations can and do establish throughout the year which may require management, in particular in CUPS, IPCs, and fruit intended for fresh market. We are currently testing a range of contact and systemic insecticides in the CREC research groves. These tests include efficacy testing at 0, 7, 14, 21, and 28 days after treatment to better understand the potential of residual to management population build up. The recent rains have delayed our second round of trials, which we anticipate starting again the week of September 19. These are tests that are not part of routine insecticide evaluations but are important to help growers understand what materials may be better options to incorporate into their programs. (d) Fire ant management as part of lebbeck mealybug managementNo new data this quarter- still working on publishing (e) Evaluate management options for IPCsNo work done this quarter. II. Long term managementa. Assessment of predator- what is currently in the system, can they be enhanced, how to implement use of predators alongside insecticide use for ACP and mealybugsData presented in previous quarter has encouraged a classical biological control researcher within UF to start working on the basic research needed to determine if any of the predators identified by our work could be targets for mass rearing and release for management. Their work is currently funded using their UF faculty start up package while they seek funding opportunities. b. Determine how to implement mealybug management concurrent with other pest management programsNo new data to report this quarterc. Determine what insecticide chemistries inhibit feedingFeeding interactions between lebbeck mealybug and citrus hosts is currently being documented, with the goal of starting insecticide assays in mid fall 2022. The new postdoc has taken up the data amassed in the past year to decipher the various interactions in the overall feeding process and compare those with other hemipteran pests. Once these behaviors are fully documented, we can determine optimal insecticide rates for killing feeding lebbeck mealybugs, which will reduce population growth and can be used to help develop optimal rates for use in IPCs. d. Develop tools to minimize spreadNo new data to report this quarter II. Next quarter:1b,c. and 2b We are continuing to test promising insecticides using field aging to determine duration of efficacy post-application. Adjuvant + Delegate trial was no completed as planned in the previous quarter in the absence of the postdoc, so that will be completed in the upcoming quarter. 2c. We will complete the feeding interaction documentation and move into insecticidal drench assays to look at impacts of insecticide on the feeding interaction. 2d. Develop protocol for sanitation using solarization and freezing (not completed last quarter as planned) III. Budget statusWe have had to request to move funds into our materials budget to cover increased gas/travel costs to the Lake Placid research site and for additional trees to maintain lebbeck mealybug colonies on. The mealybugs destroy plants at a faster rate than anticipated.       


Your browser does not support pdfs, click here to download the file.