Researcher aims to find out which insects are best at eating pests

Innovative approach using DNA testing could help crop growers reduce reliance on chemical pesticides and conserve beneficial bugs.

Calosoma calidum, the fiery hunter beetle

U of A entomologist Boyd Mori is using next-generation DNA analysis to find out whether ground beetles like Calosoma calidum, the "fiery hunter," can serve as an effective, natural method of pest control for crop growers. (Photo: Supplied)

Fields used to grow food are naturally crawling with insects—but which ones can help crops just by being there? A University of Alberta research program aims to find out.

Using next-generation DNA analysis, researcher Boyd Mori of the Faculty of Agricultural, Life & Environmental Sciences is looking to see which creepy-crawlies can be harnessed to act as the most effective natural method of pest control, just by doing what they do best: eating their fellow insects.

The initiative, started last fall, is one of the first to do this type of new testing specifically with insects on the Prairies, said Mori, who holds a Natural Sciences and Engineering Research Council of Canada (NSERC) Industrial Research Chair in Agricultural Entomology.

“We use a lot of herbicides, insecticides and fungicides on crops, so if we can reduce their use we can potentially reduce some non-target effects—we don’t want to kill neutral insects.”

Boyd Mori, Entomologist, Faculty of Agricultural, Life & Environmental Sciences

The soil is teeming with “generalist” insects—those with a broad diet of other bugs, slugs, plants and seeds—but not a lot is known about which ones make the best crop protectors, he said.

“We’ve focused on particular pests and how to control them, but there’s so much we still don’t know about their natural enemies, and there's been less of a focus on these generalists. They can potentially help farmers, and we want to know which ones are doing the best job.”

Finding out which ones have the most potential can help provide growers with sustainable pest control strategies that reduce reliance on chemical pesticides and help conserve insects that are beneficial to crops, such as pollinators like bees and and other natural enemies like lacewings, ladybugs and ground beetles. 

“We use a lot of herbicides, insecticides and fungicides on crops, so if we can reduce their use we can potentially reduce some non-target effects—we don’t want to kill neutral insects,” Mori noted.

His team of graduate students is focusing on what one particular group of insects—ground beetles—are eating in the field, using molecular gut content analysis. As one of the most diverse groups of species on Earth, they are also important generalist insects, said Mori. 

“We can dissect the gut and use next-generation DNA sequencing to figure out what the insect has been eating,” Mori explained. “We’re hoping to find that they are feeding on our pest species. That tells us which are the most important species to work on conserving.”

The research will focus on discovering whether ground beetles feed on pests specific to wheat, canola and legume crops, and whether they’re also eating neutral insects like earthworms. One of his students is also studying ground beetle predation of weed seeds in hopes of determining which species of weed seeds the beetles are consuming in the field and what impact this may have for weed management. 

As part of his NSERC research, Mori and his team are also studying insecticide resistance in the alfalfa weevil, mapping out areas where the weevil is resistant and any natural enemies that are present to help control the culprit, which devours the leaves of the valuable crop plant.

Mori hopes to have some preliminary results by this summer, which will be shared with the projects’ industry partners: the Canola Council of Canada, the Alberta Canola Producers Commission, the Alberta Wheat Commission, Alberta Barley and the Alberta Pulse Growers

Those groups can then share the findings with farmers to start thinking of ways to retain beneficial insects in their fields, Mori said.

“We can tell them these are the ones that are most important, and by doing this across different crops, we’re hoping there’s some commonality among them all so we can conserve similar species of insects across the crops in the future.”

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