Herbicides and Butterfly Decline: The Transformation of U.S. Agriculture and the Cost to the Ecosystem

Herbicides and Butterfly Decline: The Transformation of U.S. Agriculture and the Cost to the Ecosystem

The mass use of the herbicide glyphosate (trademarked Roundup) in the United States expanded rapidly with the introduction of genetically modified resistant crops (Roundup Ready varieties) in the mid-1990s. By making major crops such as soybeans, corn, and cotton resistant, farmers were able to facilitate weed management and dramatically increase production efficiency. Behind the scenes, however, insect and plant diversity took a major hit.

As a historical background, from the 1980s to the 1990s, U.S. agriculture was focused on the supreme goals of "efficiency" and "global market competitiveness," and biotech companies and chemical manufacturers worked together to promote genetically modified crops. While increasing profitability in the international market, the pesticide-dependent agricultural model was strengthened, and economic rationality took precedence over ecology.

The monarch butterfly (Monarch butterfly) is a prime example of the impact of this process. The only food source for the larvae, the cornflower, which used to grow commonly in fields and along the margins, was almost completely eradicated by glyphosate spraying, resulting in a catastrophic loss of larval habitat. As a result, populations have plummeted across North America since the 1990s, and the migratory swarms are shrinking year by year.

Recent studies also suggest that glyphosate may disrupt the gut microbiota of honeybees, reducing their resistance to pathogens. Damaging bees, which are responsible for pollination, is a "self-contradiction" that conversely threatens agricultural production itself.

In the 2000s, the emergence of herbicide-resistant weeds led to a rather large increase in pesticide use. This indicates that contrary to the promise of "reduction of pesticide use," agriculture has fallen into a vicious cycle of chemical dependence. Despite international advocacy for sustainable agriculture and a shift to organic farming, glyphosate use remains extensive in the U.S., which is based on large-scale farming.

The decline of herbicides and butterflies is not just an environmental issue, but a mirror of the state of agricultural policy, corporate strategy, and consumer society in the late 20th and early 21st centuries. Ecological loss, overlooked in the shadow of efficiency, has become a serious issue in an era of sustainability.