29 Apr 2025

How Farmers Are Fighting Dreaded Agricultural Pest

29 Apr 2025

The European corn borer is one of the most prevalent pests across the world. It feeds on multiple species of plants, with corn being the most prominent. Today, this pest is making its way back into larger numbers in North America, and farmers are working hard to adapt control strategies.

Back in the 90s, farmers lost billions to the European corn borer (ECB), then deemed the “billion-dollar bug”. At the time, scientific advances led to the development of hybrid corn species inoculated with the bacterium Bacillus thuringiensis (Bt). This suppressed the borer populations and effectively wiped them out.

But today, the bug is back. It’s been making its way through North America, starting in Canada. Farmers have to adapt quickly to control its spread. Here’s how they’re battling the billion-dollar bug.

The History

Larvae sneak into stems, hiding out until spring warmth arrives.

The European corn borer life cycle begins when the adult form of Ostrinia nubilalis (a moth) lays small egg masses on the leaves of its favored crop and the stems of nearby weeds. Larvae hatch and bore into the stem of the plant they’re laid on, and overwinter.

As spring arrives, they emerge as adult moths, ready to carry on a new generation. Depending on the species, there may be one to three generations per year, and up to 400 eggs laid within a ten day period.

This pest has been present in North America since the early 1900s. It’s believed to have originated in Western Asia and Europe, but this isn’t confirmed. The larvae’s propensity to feed on tassels and kernels, as well as the ear shank, is what makes it so damaging. In the process, the crop is rendered unconsumable.

The Solution

Harvesting for silage gave farmers a built-in advantage.

To combat the voracious larvae, initial methods of control involved cultural practices. Overwintering borers are generally destroyed when corn is harvested for silage. In areas where topsoil preservation isn’t as important, stalk-shredding and deep moldboard plowing are effective controls. Pesticides were also used to eliminate moths and larvae.

However, timing the pesticide appropriately across the massive scale of many farms was almost impossible. In response, agricultural scientists developed the first strains of Bt corn. These genetically modified strains made it so larvae that fed on the corn died in the process. And up until recently, this was considered the most effective treatment.

Bt strains work through the production of bacterial spores. Larvae feed on the spores, which contain a protein that ruptures their stomachs and kills them. These genetically engineered strains made it so the bacteria were present throughout the plant’s life cycle, as opposed to intermittently as with pesticides. With promising results, these strains became widely available in 1996.

SHARE :