Monarch Butterfly Concerns Still With Us

Years ago, the seed companies blasted a USDA researcher after I wrote a No-Till Farmer item stating that Bt corn could reduce butterfly populations. While there has been plenty of controversy over the years on whether pollen from Bt corn is toxic to butterflies, later research demonstrated that criticism of the researcher’s findings was not justified.

In 1999, the relationship between monarch butterflies and Bt corn was confirmed when a Cornell University study indicated that Bt corn pollen could poison monarch butterfly larvae. Leading to a public outcry in Europe against biotech corn, these findings led to calls from environmental groups to slow the spread of gene-altered crops.

Even though pollen from Bt corn can be toxic to butterflies, the risk is extremely low. In fact, data from several research studies estimates that pollen from Bt corn kills less than 0.05% of monarch butterflies in the Midwest each summer.

Billions Down to Millions

But with a serious decline in monarch butterfly numbers, in 2022 the International Union for the Conservation of Nature (IUCN) added the migratory monarch butterfly to its endangered and threatened species list. This decision was based on data showing that while there were as many as 1 billion monarchs on the planet in the 1990s, these numbers have dropped to only around 33 million in 2022.

This sharp decline in the monarch butterfly population could lead to trouble among all pollinator species, such as butterflies and bees. The Center for Biological Diversity describes the decrease in monarchs…

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Lessiter frank

Frank Lessiter

Frank Lessiter has served as editor of No-Till Farmer since the publication was launched in November of 1972. Raised on a six-generation Michigan Centennial Farm, he has spent his entire career in agricultural journalism. Lessiter is a dairy science graduate from Michigan State University.

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