Study: German cockroach evolving to glucose-free diet

Photo: Erik Karits/shutterstock.com

The German cockroach (Blattella germanica) is evolving to have a glucose-free diet, according to new research from North Carolina State University (NCSU).

The cockroaches are evolving to dislike sugar, specifically glucose, to outwit human pest control tactics. This could have huge implications for the population of cockroaches worldwide, especially since they spread bacteria and disease.

Scientists at the university study roach reproductive habits and evolutionary adaptations. Dr. Ayako Wada-Katsumata and a team of entomology research found evidence of significant changes involving sugar-averse German cockroaches and mating habits.

According to Dr. Coby Schal, professor of urban entomology, insect behavior, chemical ecology, insect physiology and head of the eponymous Schal Lab at NCSU, the team’s new research shows that cockroaches have begun to deviate significantly compared to previously observed roach-mating behavior.

Female lab cockroaches included a significant population of glucose-verse roaches. Researchers found these roaches were unwilling to complete traditional roach mating behavior, accepting what the research study refers to as “nuptial gifts” or “nuptial feedings.” These glucose-adverse female roaches also chose not to complete the mating process, meaning there wouldn’t be any reproduction.

This does not mean there will be a drop in the cockroach population. Male roaches eventually found another way to reproduce.

The researchers found male roaches overcame female glucose aversion during mating time. Roach mating lasts for up to 90 minutes. Male roaches adapted to female roach glucose hesitancy and shortened their mating rituals down to minutes or even seconds, while successfully completing fertilization.

Photo: Mark Sheperdigian

The studies showed the most successful mating pairs were males and females who were both glucose averse. The least successful mating pairs were females who were glucose averse roaches with wild-type or glucose-loving males. While there were short-term population dips among glucose-averse females and wild-type males mating pairs, other more successful matches, including male and female roaches that were both glucose averse.

Overall, the entire roach population within the lab study stayed within normal predicted ranges, despite this population of sugar-eschewing insects.

According to Dr. Schal, researchers are wondering if new behavioral traits like this could spread through different populations, making this mutation more prevalent.

“One of the takeaways is that animals, including roaches, have adaptations that they evolve in terms of natural selection,” Dr. Schal said in the study. “German cockroach, a pernicious household pest, plays an important etiological role in allergic disease and asthma. It also serves as a mechanical vector of pathogens, including antibiotic-resistant microbes.”

This new behavioral trait among roaches throws a wrench in traditional pest management control techniques that use sweet poison.

According to Dr. Schal, roaches typically dislike bitter-tasting food items and prefer sweet food items. Traditionally, roach pest management has tried to improve the taste of bitter-tasting poisonous bait by wrapping sweetening-agents around the roach poison.

Among urban roaches, it is currently unclear what the ratio is of glucose-averse to glucose-loving roaches. If this trend is ongoing among urban roaches, the majority may become glucose-averse at some point in the future.

The post Study: German cockroach evolving to glucose-free diet appeared first on Pest Management Professional.

from Pest Management Professional https://www.mypmp.net/2022/07/14/study-german-cockroach-evolving-to-glucose-free-diet/
Sacramento CA