Source: TEXAS A&M UNIVERSITY submitted to
DEVELOPMENT OF DECISION TOOLS AND CULTURAL PRACTICES FOR MITIGATING THE IMPACT OF THE MEXICAN RICE BORER (EOREUMA LOFTINI) IN GULF COAST
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
OTHER GRANTS
Reporting Frequency
Annual
Accession No.
1031009
Grant No.
2023-70006-40606
Cumulative Award Amt.
$325,000.00
Proposal No.
2023-02987
Multistate No.
(N/A)
Project Start Date
Sep 1, 2023
Project End Date
Aug 31, 2026
Grant Year
2023
Program Code
[ARDP]- Applied Research and Development Program
Project Director
Bernaola, L.
Recipient Organization
TEXAS A&M UNIVERSITY
750 AGRONOMY RD STE 2701
COLLEGE STATION,TX 77843-0001
Performing Department
Entomology
Non Technical Summary
The Mexican rice borer (MRB), Eoreuma loftini, has emerged as an important pest of rice along the Gulf Coast (southwestern Louisiana and eastern Texas). Current management program for this insect is unsustainable because it relies almost exclusively on a single insecticidal seed treatment. The sustainability of the management program for MRB would be improved by integrating foliar insecticides into the program. Interactions of rice with the MRB, like rice-stem borer interactions in general, are complicatedand prevention of yield losses from borers is a bigproblem. Integrating foliar insecticides into the management program for the MRB will require a more detailed understanding of the interaction between rice and the MRB. We propose to characterize the relationship between rice plant age and vulnerability to MRB and use this information to develop a crop model to guide decisions about scouting and treatment for the MRB. In addition, we propose to investigate yield losses from MRB at different rice panicle densities and use this information to develop cultural control practices for MRB. To accomplish these goals, multilocation greenhouse and field experiments in Louisiana and Texas will be conducted across three years to understand the relationships of rice ageto susceptibility to MRB. Findings will be disseminated to growers, consultants, and the scientific community to improve the productivity of rice through more effective integrated pest management of stem borers.
Animal Health Component
90%
Research Effort Categories
Basic
0%
Applied
90%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
21615301130100%
Knowledge Area
216 - Integrated Pest Management Systems;

Subject Of Investigation
1530 - Rice;

Field Of Science
1130 - Entomology and acarology;
Goals / Objectives
Objective 1: Characterize the vulnerability of rice to MRB as a function of plant age/stage in three inbred varieties.Objective 1a. Characterize the relationship between rice plant age/stage on susceptibility to oviposition preference in three rice varieties.Objective 1b. Characterize the relationship between rice plant age/stage on susceptibility to losses in grain yield in three rice varieties.Objective 2: Develop new specialized rice phenology model to predict the timing of rice stages most vulnerable to MRB and verify the effectiveness of the model.Objective 2a. Develop specialized rice phenology model to predict the timing of vulnerable ontogenetic stages to MRB in three inbred varieties using data generated in Objective 1.Objective 2b. Assess the efficacy of the model by using it to time applications of foliar insecticides against MRB in field plots of rice.Objective 3: Characterize the relationship between incidence of MRB (deadhearts and whiteheads) and yield loss at a range of panicle densities in three inbred rice varieties.Objective 4: Develop decision tools for management of MRB including an online scouting guide and yield loss calculator.
Project Methods
Briefly, underObjective 1, we will conduct multi-location greenhouse experiments to determine the effect of plant ontogeny (growth stage) on the vulnerability of rice plants to stem borers, where vulnerability is defined in terms of both susceptibility to oviposition and susceptibility to yield loss on a per-plant basis. Activities will begin immediately at project start date, and greenhouse experiments and statistical analyses will be concluded by the end of Year 2.Briefly, underObjective 2, we will develop a rice phenology model to predict the timing of various ontogenetic stages in rice vulnerable to MRB as determined by the results of greenhouse experiments inObjective 1. This model will then be verified by using it to time applications of foliar insecticides in multi-location rice field plots to coincide with periods of high vulnerability to stem borers. Activities within this objective will begin immediately at Year 1 and be completed by the end of Year 3.Briefly,underObjective 3, we will characterize the relationship between MRB incidence and yield loss at different panicle densities by manipulating panicle densities in multi-location field plots byvarying rates of seeding, then calculating the percent yield loss per deadheart or whitehead under natural infestations. Years 2 and 3 will be required for the development of preliminary thresholds for foliar insecticide applications against MRB.Briefly, underObjective 4, we will develop extension tools for MRB management that will be communicated to growers and stakeholders in Texas and Louisiana. Years 1 to 3 of the project will be required for generating a scouting guide for borers in rice, and Years 2 and 3 will be devoted for developing a yield loss calculator and for communication of results to growers.

Progress 09/01/23 to 08/31/24

Outputs
Target Audience:Target audience: rice producers/growers, extension agents, scientists Scientific conference of the EntomologicalSociety of America: Entomology Annual Meeting 2024 Rice field day at Texas A&M AgriLife Research, Beaumont, Texas in July 2024 Rice Field Day Student CompetitionJuly 2024 Changes/Problems: Funding was provided in August 2023 but was not used until January 2024 when the graduate student was able to start. This delayed progress on the objectives. What opportunities for training and professional development has the project provided? Graduate student has received training in field operations of the rice crop from planting to harvesting. Collected research data and learnt to use statistical software such R. Graduate student has participated in field days, thereby interacting with rice stakeholders. How have the results been disseminated to communities of interest?Until August 2024, thegraduate student has participatedin a Rice Field Day at the Texas AgriLife Research Center at Beaumont. What do you plan to do during the next reporting period to accomplish the goals? Continue collaborating with LSU to progress this project by having Zoom meetings and discussions during field days and conferences. Continue mentoring the graduate student in presenting her data at scientific conferences and future field days.

Impacts
What was accomplished under these goals? In a few sentences, what is the issue or problem that your project addresses (i.e.; what are you trying to help solve, fix, mitigate, improve?) The Mexican rice borer (MRB) hasemerged as an important pest of rice along theGulf Coast (southwestern Louisiana and eastern Texas). The current management program for thisinsect is unsustainable because it relies almost exclusively on a single insecticidal seed treatment. Who or what will be most immediately helped by your work, and how? (Hint: What audience did you originally intend for your work to impact?) Rice producers/growers in Texas and Louisiana For each major goal listed in your project initiation form (shown at the top of the screen), describe for this reporting period: For Objective 1: This no-choice experiment aims to characterize the relationship between the plant growth stage and the insect's ability to complete its life cycle, as well as the time required for each developmental phase. In addition, Whitehead symptoms development, measuring the incidence and how fast the whitehead formation happens across the three rice varieties at each growth stage to identify which variety and stage combination shows the highest susceptibility to damage.Progress made in objective1a by conducting the Year 1 of two years of greenhouse experimentsto evaluate the susceptibility of three different rice varieties at four distinct growth stages (mid-tillering, panicle differentiation, booting, and heading)to infestation and damage by the Mexican rice borer.The analysis of the mean number of whiteheads for each rice variety across different growth stages (Heading, Panicle, and Booting) using ANOVA revealed no significant differences. For the Heading stage, the p-value was 0.0915, indicating a trend toward differences between varieties, but it did not meet the conventional significance threshold of 0.05. At the Panicle stage, the p-value was 0.84, and at the Booting stage, the p-value was 0.116, both of which suggest no significant differences in the number of whiteheads among the varieties. These results indicate that, in this experiment, the rice varieties (PVL03, Jupiter, and CL111) did not exhibit significant variation in their susceptibility to MRB infestation across the tested growth stages. For Objective 3: Progress made; Year 1 of two years. A field experiment was used to investigate the impact of different seeding rates on the incidence of whiteheads and subsequent yield loss in rice crops in Texas. This study compares two rice varieties, Cheniere and Jupiter, cultivated in Beaumont and Eagle Lake locations, respectively. The experiment is designed as a 5x2 factorial, encompassing five seeding rates (35, 70, 105, 140, and 175 lb/acre) and two insecticide treatments (Dermacor X-100 treated and untreated plots). Then we analyzed the effect of seeding rates on the percentage of yield loss and identify any correlations between whitehead density and yield reduction. Analysis of variance (ANOVA) indicated that the interaction between seeding rates and insecticide treatments was significant (p = 0.05). When comparing the levels of insecticide treatments, the results showed that control plots had a higher mean number of whiteheads compared to the plots treated with Dermacor. This suggests that Dermacor effectively reduced Mexican rice borer damage.In addition, the analysis demonstrated that seeding rate was the only significant variable affecting mean yield. During the first year, lower seeding rates corresponded with lower yields, while higher seeding rates were associated with increased yields. In contrast, at higher seeding rates (105, 140, and 175 lb per acre), control plots showed slightly lower whitehead counts but without significant yield differences. This trend suggests a potential yield plateau at higher seeding rates, potentially due to resource competition or shading effects caused by denser foliage, which limits light penetration and impacts growth. Describe the key outcomes or other accomplishments realized. In a few sentences, what did your project do about this issue/problem during this reporting period? (HINT: Revisit your logic model's inputs, outputs, and outcomes to describe accomplishments) For objective 1: Conducted first year of greenhouse experiment to characterize the relationship of rice plant age/stage to susceptibility to MRB oviposition. Proposal presented at the Student Competition of the 2024 Rice Field Day at Texas AgriLife Research Center in July (won second place). For Objective 3: Conducted first year of multilocation field experiments to determine relationship of MRB density in yield loss. Presented this research during the 2024 Rice Field Day at Texas AgriLife Research Center in July.

Publications