Investigating Novel Sources of Resistance to Wheat Stem Sawfly, a Devastating Pest of Wheat

College of Agricultural Sciences

Agricultural Biology

Larimer 

County 

(Morgan, Phillips, Sedgwick, Weld)

Primary Topic:

Agriculture

Other Topics:

Horticulture

Lead Mentor:  

Adam Osterholzer

Research Associate

Internship Overview:

Wheat stem sawfly is a prolific pest in Colorado grown wheat and causes an estimated $40 million in losses annually. It is particularly damaging in northeastern Colorado. It is a stem boring pest that spends much of its lifecycle inside of stems, making traditional insecticides ineffective as control measures. Solid stem varieties of wheat have been shown to be effective in impeding larval development and movement, thus reducing larval survival. However, the solid-stemmed cultivars are not preferred by growers because of low yield (10-15% reduction) compared to hollow-stemmed cultivars and inconsistent solidness expression. Given the limited sources of resistance to wheat stem sawfly in the current breeding germplasm, there is a need to evaluate diverse wheat genetic resources for additional alleles that can enhance development of wheat stem sawfly-resistant varieties. Applied research on this topic has been ongoing at CSU for over ten years and continues to be a major point of interest for the crop entomology research group.

A student intern is needed to investigate possible resistance mechanisms in wild wheat relatives to wheat stem sawfly. They will achieve this by carrying out an experiment that will involve growing wild wheat species in a greenhouse, transporting these plants to a local producer’s fields with heavy wheat stem sawfly infestation, and then collecting data on the insect’s development within plants. This objective will take place mainly on CSU’s main campus (Larimer county) with some field collections in Weld and Morgan County farms. This data will be critical for wheat breeders to integrate into their breeding decisions as they find novel ways to combat this pest.

There are a myriad of research projects involving wheat stem sawfly every year at CSU. Our outreach objective for the student intern will ensure that this research project is adequately explained to local stakeholder groups and producers as the intern fosters connections with those groups through their writing and in-person extension activities. The extension outreach events will take place in Sedgwick, Phillips, and Morgan counties, with the outreach newsletters reaching a wider audience of nearly all wheat growers in eastern Colorado.

Goals, Scope and Objectives:

The long-term goal of this project is to evaluate wild wheat species for additional alleles that can enhance development of resistant varieties against the wheat stem sawfly. To this end, we are collaborating with the Wheat Genetics Resources Center at Kansas State University that houses diverse wheat species.

Objective 1: The first goal of this internship is to investigate resistance mechanisms in wild wheat to the wheat stem sawfly (Cephus cinctus Norton). The student intern will be involved in all aspects of the project, beginning with growing wild wheat species in the greenhouse. These plants will be infested with wheat stem sawfly at a field location. Data will then be collected on the insect’s performance in the wild wheat species.

Objective 2: The second learning objective is to have the student intern participate in extension outreach events and meetings to understand the role of extension in research. This will be achieved through a pair of smaller objectives: (1)The intern will attend the annual “Wheat Field Days” where extension agents and farmers meet and talk about current research, and (2) the intern will help prepare portions of extension reports that will be sent to local stakeholders involving their research project.

With which stakeholder group(s) will the intern work?

The intern will work closely with Adam Osterholzer (Research Associate), who will be coordinating the research experiment. Dr. Nachappa will act as a faculty mentor to the intern and facilitate the intern meeting their professional and personal goals. Extension mentor Kat Caswell will spearhead the extension objectives by showing the intern how extension interacts with local stakeholders/farmers. The intern will also interact with the regional stakeholder group, the Colorado Wheat Administrative Committee. This group organizes the Wheat Field Days events and will coordinate the publication/distribution of the newsletters the intern will help write.

What student learning outcomes do you anticipate and what are the opportunities for professional development?

The intern will learn firsthand about applied agricultural research techniques in dryland cropping systems. Additionally, they will learn insect identification and collection techniques, as well as data management, analysis, and writing procedures for effective communication. Research activities may include: caring for experimental plants in the greenhouse, setting up experimental plots, collecting and identifying insects, collecting data at on-farm experimental plots, and aiding in analyzing and reporting findings. The intern will have interactions with local stakeholders in the wheat industry and will learn about the role of extension agents in facilitating research.
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