Rob Williams

By: Kay Ledbetter, Texas A&M AgriLife Communications

AMARILLO – Dr. Ada Szczepaniec has been hired as an assistant professor and research entomologist by Texas A&M AgriLife Research in Amarillo and the Texas A&M University department of entomology. She began Sept. 14.

“Dr. Szczepaniec possesses an excellent academic and field research background that will allow her to quickly establish a strong entomology research program directed primarily on cropping systems that include wheat, corn or sorghum,” said Dr. John Sweeten, AgriLife Research resident director in Amarillo.

“Her strong personal attributes should promote collaborative research teamwork with other faculty at the Texas A&M AgriLife Research and Extension Center at Amarillo and our partnering agencies and universities,” he said.

Szczepaniec earned her bachelor’s degree and doctorate from the University of Maryland and served as a laboratory technician and teaching assistant in the department of entomology there for several years before moving to College Station.

She worked as a postdoctoral research associate in the department of entomology at Texas A&M, where her research focused on the impact of neonicotinoid insecticides on plants and non-target organisms.

Her research demonstrated that applications of neonicotinoid insecticides suppress important plant defense genes, alter levels of phytohormones involved in plant defense, and decrease plant resistance to an unsusceptible pest in multiple, distantly related plants.

Szczepaniec said her’s was the first study to document insecticide-mediated disruption of plant defenses and link it to increased population growth of a non-target herbivore.

“Our findings were important because applications of neonicotinoid insecticides have been associated with outbreaks of spider mites in several unrelated plant species,” she said.

“This study added to the growing evidence that bioactive agrochemicals can have unanticipated ecological effects and suggested that the direct effects of insecticides on plant defenses should be considered when the ecological costs of insecticides are evaluated.”

In another study looking at the treatment of elms in Central Park in New York City, Szczepaniec concluded that the widespread use of neonicotinoid insecticides such as imidacloprid increased spider mite fecundity and created the pest outbreak.

Most recently, she was an assistant professor at South Dakota State University, where she had a 75 percent Extension and 25 percent research appointment.

Szczepaniec continued her work on non-target effects of neonicotinoid insecticides in soybeans and worked on the management of corn rootworm in corn. She also conducted numerous efficacy trials on those crops and had an active Extension and outreach program.

“I learned during that time from stakeholders about what some of the limitations might be on what we recommend for them to do,” she said.

But in the end, she said she wanted to get back to Texas A&M and back to applied research.

In her new position, Szczepaniec said she will conduct research on the impact of drought on insect management in cropping systems, continue her work on insecticide resistance management and study new and emerging insect pests in the region.

Beetles can teach us a lot of things about genetics, especially with regard to differences in genome size within and between species. Professor Spencer Johnston worked with a team of scientists to test how the genome size affects reproductive fitness in seed beetles.

Led by Goran Arnqvist of the University of Uppsala in Sweden, the researchers have presented evidence suggesting that natural selection may be a more important determinant of genome size than chance events (genetic drift). In the study published in the September 2015 issue of the Proceedings of the Royal Society of London, they found no evidence that genome size is determined by random processes.

Johnston said they conducted a phylogenetic comparison of 12 species of seed beetles to describe the tempo and mode of the genome size evolution in the group, as well as to test if there was any correlation in evolution between the size of genome and body size at an interspecific scale.

The group also used a second group of 18 distinct genotypes of the main model species, Callosobruchus maculatus, to characterize interspecies variation in genome size and to ask whether genome size shows correlated evolution with life history and sex-specific fitness.

There was a reason to study this particular organism. These beetles are considered pests because their larvae infest seeds of legumes, such as soybeans and cow peas, doing considerable damage.

The researchers found that within the groups of seed beetles studied, the genome size was directly and positively related to successful reproduction in both males and females. The results suggest that variation in genome size may be much more important than previously believed.

Dr. Johnston said that novel analytic methods used in this study could be adapted to study other insects and could possibly help find new and improved methods of controlling the beetles and other pests.

“I have long sought evidence that genome size variation was adaptive.  This is of interest, because we often find genome size differences among populations, including mosquitos and other very serious pest insects,” Johnston said.  “Here we find that the populations with larger genomes have higher lifetime fecundity in females and greater competitive success as males.  What I find interesting is that we really do not know why this should be so.  It opens a whole new area for control efforts.”

The article can be found here: http://rspb.royalsocietypublishing.org/content/282/1815/20151421