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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, 2022

Objective:
1) Initiate and maintain in PGRU a non-diapausing northern corn rootworm (NCR) colony developed by USDA-ARS Brookings, SD as a control for assays evaluating wild NCR susceptibility to Bt toxins and 2) Continue to evaluate multiple wild northern corn rootworm populations both plant and diet assays in toxicity assays to Cry3Bb1 protein as well as Cry34/35Ab1, if available. 3) Initiate and maintain a non-diapausing northern corn rootworm (NCR) colony developed by USDA-ARS Brookings, SD as a control for assays evaluating wild NCR susceptibility to Bt toxins. 4) Evaluate multiple wild northern corn rootworm populations in both plant and diet toxicity assays forCry3Bb1 protein as well as Cry34/35Ab1, if available.

Approach:
A non-diapausing strain of the northern corn rootworm (NCR) has been developed by USDA-ARS, Brookings, SD. We have recently obtained eggs from this strain so that we do not need to continually obtain eggs from their diapausing NCR strain. We will utilize traditional rearing approaches similar to how we currently rear a number of non-diapausing strains of the western corn rootworm, but initially will adopt slight modifications suggested by Brookings. For Objective 2, we will utilize eggs from the new NCR non-diapausing strain as a susceptible control when evaluating field strains. Currently, we have eggs from four different 2018 wild populations. We will evaluate these in plant and diet assays to Cry3Bb1 and to Cry34/35 in plant assays and diet assays, if possible. In addition, collections will again be made in 2019 to evaluate additional NCR populations. If possible, we will target NCR populations that have greater than expected damage to Bt corn in 2019. We will utilize traditional rearing approaches for the diapausing NCR strain, similar to the methods used to rear non-diapausing strains of the western corn rootworm, with slight modifications. For Objective 4, we will utilize eggs from the new NCR non-diapausing strain as a susceptible control when evaluating field strains. Currently, we have eggs from four different 2018 wild populations. We will evaluate these in plant and diet assays to Cry3Bb1 and to Cry34/35 in plant assays and diet assays, if possible. In addition, collections will again be made in 2019 to evaluate additional NCR populations. If possible, we will target NCR populations that have greater than expected damage to BT corn in 2019.