Researcher has plan to help sorghum pest control 

Haley Butler, a research entomologist at the peanut and small grains unit of the U.S. Department of Agriculture-Agricultural Research Service, recently discussed her five-year research plan to help address the chinch bug in sorghum. Butler spoke during a Center for Sorghum Improvement seminar.  

Based in Stillwater, Oklahoma, Butler received three degrees from Oklahoma State University and she has always been interested in the interactions of organisms. 

“I started out as an undergrad in wildlife biology, and I slowly transitioned to entomology, where I could still study ecology and how organisms interact with each other, and apply that to something like integrated pest management,” she said. “My first class that I took with integrated pest management, I really enjoyed it so it kind of set the stage for my future research.” 

Her doctorate research came after aphids invaded sorghum and her adviser guided her along the way. 

“Once the sorghum aphid arrived, we saw a different response between the native parasitoids and how they responded to the aphid,” she said. “It actually altered the dynamic of the parasitoid community, and my job was to try to study the competition between the two parasitoids and how their competition and interactions impact their ability for biological and aphid suppression in sorghum.” 

She did many small- and large-scale greenhouse studies with parasitoid competition, how they interacted and how many aphids were able to be parasitized when they were foraging along or together.  

“This kind of background helped me transition into this chinch bug project,” Butler said.  

When she was hired by ARS, during her first week she called stakeholders who collaborated with the USDA in Stillwater and they all replied chinch bug was a priority. 

Many of those she spoke with said the intensity and duration of the chinch bug pressure has increased in recent years. 

“The biggest problem is that there are very few IPM management tools available for producers to mitigate and combat this pest,” she said. “So that’s how I decided which objectives to focus on for chinch bugs.” 

Sorghum production is “extremely important” for the region where Butler is located and the U.S. is the No. 1 producer of sorghum in the world, she said. Oklahoma, Kansas and Texas produce the majority of sorghum and its drought tolerance is an important trait. 

“It’s becoming, I feel, more popular, because you can plant it in dry land. You don’t have to irrigate it. And it’s just a really nice crop for this area of the country,” she said. 

Bug specifics

Butler focuses on the common chinch bug, but there are other different species of chinch bug that look very similar. The most prevalent is the common chinch bug and it’s native to North America. It feeds on and overwinters in wild prairie grasses.  

“The whole landscape is their smorgasbord. It’s like a buffet,” she said. “They’re grass feeders. So, if they move out of the wild prairie grasses, they’re just going to move right into your sorghum, your wheat, corn millet, like any kind of small grain. Unfortunately, they have a lot of resources to survive and then become a pest in agricultural crops.” 

From egg to adult, it takes about 30 days depending on temperature, and once they reach adulthood, they live two to three weeks and have five nymphal stages. Since they are similar to other species, Butler said its important producers know what they’re scouting in the field.  

Chinch bugs are damaging because of their piercing and sucking mouth parts. 

“They have these little stylets that they insert into the plant tissue, and they suck all of the plant juice out, and then that’s what causes the damage, the necrosis, the dwarfing, lodging, all of that is due to their feeding,” Butler said.  

The first generation of chinch bug emerges from the overwintering habitat and into sorghum, is also the most damaging because of the feeding behavior.  

Payne County, where Stillwater is located, has been a heavy infestation area for the chinch bug and reaches to the Kansas border.  

Gap in research

According to Butler, there’s a gap in chinch bug research and she believes there’s several reasons.  

“They’re more abundant during drought periods and the focus has shifted,” Butler said. “The focus was shifted to other important pests, like sorghum aphid.” 

When the sorghum aphid came in 2013, chinch bug research stopped.  

“We had all these chinch bug studies prepped, and then sorghum aphid came in and really was destroying sorghum. So, we had to stop,” Butler said. “I feel like there’s been a lot more pressing pests before the current moment with chinch bug. So, a lot of research was shifted over to those areas.” 

Objectives

For the next five years, Butler will focus on three objectives—chinch bug population monitoring in grain sorghum, establishing that chinch bug rearing protocol and evaluating different sorghum varieties for possible resistance. 

“I want to be able to provide producers with a solid list of hybrids, or anything that they could possibly plant next year to try to mitigate some of that pressure, because that’s very needed right now,” she said. 

Butler hopes through research experts can gain a better understanding of chinch bug biology, population ecology and how damage relates to their surrounding landscape. 

“Also, the standardized rearing protocol is super important to try to accelerate the rate at which we’re screening these hybrids and germplasm,” she said. “And then also just to provide a nice set of integrated pest management tools for producers to deal with chinch bugs, because it’s a huge problem.” 

Butler believes chinch bugs are here to stay and if it does happen to rain, summer might be a good time for testing. 

“I just don’t think that we’re going to have a lot of rain this summer, so I think the summer is a perfect time to really test some of these varieties in the field plots and doing population monitoring,” she said. “Because I think there’s going to be a lot of them out there this summer, at least in Oklahoma.” 

Kylene Scott can be reached at 620-227-1804 or [email protected].