Science Briefs: New ally found in fight against soybean pest

The kudzu bug is a type of stink bug that is an invasive soybean pest.
The kudzu bug is a type of stink bug that is an invasive soybean pest.

Another enemy of kudzu bug identified

The kudzu bug is an invasive soybean pest discovered in Georgia in 2009 that has spread to 13 states. Now a Clemson University grad student has helped pinpoint one of its foes. Research by Francesca Stubbins, an assistant at the Edisto Research and Education Center, has shown that mermithid nematodes can infect and kill the insects. Her research involved collecting kudzu bugs from soybean fields. Nematodes – long, slender, parasitic worms – were found in the abdomens of some of the dissected female insects. Stubbins also found nematodes inside kudzu bug males and nymphs.

“Not much work has been done on the Mermithidae family of nematodes so we do not know much about them,” Stubbins said. “We do know they live in soil for long periods of time and that they have been shown to infect different insect species.”

Immature nematodes enter insects, develop within the insects, emerge from insects into the soil, develop and become adults, then lay eggs. Hatched immature nematodes find insects to infect, and the cycle continues.

“This discovery adds to the list of natural enemies that infect kudzu bugs,” Stubbins said. “It does show there are natural enemies in the field that could have the capacity to reduce kudzu bug populations. This is good news for soybean growers.”

Get native plants that are for the birds

Audubon North Carolina’s Bird-Friendly Communities program, launched in 2015, continues to build connections among gardeners, bird lovers and plant nurseries, with the goal of helping the state’s beautiful and diverse bird populations.

Bird-friendly native plants are a key piece of this. One of the 2016 featured plants, American beautyberry, provides berries that offer a perfect fuel to migrating black-throated blue warblers as they pass through North Carolina. This could help more of these birds survive to better sustain the population over time.

“Over thousands of generations, birds have adapted to the native plants found in North Carolina, feeding on the native insects and berries supported by these plants,” said Curtis Smalling, the organization’s director of Land Bird Conservation. “By growing natives from Audubon N.C.’s curated list, gardeners have a great opportunity to help the birds they love while supporting local businesses and nurserymen participating in the program.”

Audubon North Carolina has created a list of plants, curated by bird and native-plant experts, to food birds need during each season. Also: a statewide list of nurseries offering these bird-friendly native plants. Details:

Hygiene behaviors help keep social insects healthy

Research from N.C. State finds that among social insects like ants, bees and termites, the more individuals there are in a typical species colony, the weaker the species’ immune response. The finding strongly suggests that hygiene behaviors, and not just immune systems, play a key role in keeping those insects healthy.

They live in groups, and living at close quarters with many other individuals would appear to increase their risk of contracting disease. Yet these insects are incredibly successful.

Is this due to stronger immune systems? Or have they evolved specific behaviors that reduce the risk of disease transmission?

Researchers tested an immune response in 11 different insect species: six that show an advanced level of social organizations, and five that do not. They found that species that show an advanced level of social organization generally had a less pronounced immune response. They also found that the larger the colony size associated with a species, the weaker its immune response.

Bottom line: Behaviors seen in social species – like grooming each other or bringing anti-fungal materials into nests or hives – “are playing an important role in colony health,” said NCSU researcher Margarita Lopez-Uribe. She is lead author of a paper on the work published online in the Royal Society’s Biology Letters.