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ARS Home » Midwest Area » Columbia, Missouri » Plant Genetics Research » Research » Research Project #433083

Research Project: Optimization of Artificial Diet for Rearing and Toxicity Assays with Western Corn Rootworm

Location: Plant Genetics Research

Project Number: 5070-21000-041-05-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Aug 1, 2017
End Date: Jun 30, 2020

Objective:
1) Characterize northern corn rootworm (NCR) tolerance to Bt in plant assays. 2) Evaluating current public artificial diets for western corn rootworm to evaluate northern corn rootworm growth and development.

Approach:
We will collect base-line susceptibility data for northern corn rootworm to each of the current single toxin Bt proteins. The laboratory northern corn rootworm (NCR) colony from USDA-ARS Brookings, SD will be used for initial baseline studies described here. For the plant assays, we will utilize standard techniques, most of which were developed in our laboratory. The bioassay data obtained from this objective from a laboratory colony that has never been exposed to Bt corn will serve as a reference point for future work wildtype northern corn rootworm strains collected under this agreement. In preliminary studies this past year, we documented that approximately 100 fold more wildtype NCR eggs were obtained from females in single cages than other female densities or 25, 100, or 500+ in a larger cage. We will repeat the study, but will compare oviposition when we change oviposition dishes daily compared to when we change them weekly in larger cages with 500+ females. We will also collect eggs from single females in small cates. For the larval diet work, the three Diabrotica larval diets most relevant to the work will be evaluated for NCR larval development. We will choose a diet for NCR bioassays based on survivorship, larval weight, contamination, and molting in a 10 day assay.