Monarch Butterflies

July 14, 1999

A few weeks ago I talked about the hysteria and misinformation surrounding frogs with missing or deformed limbs. At first it looked like a sure sign of an impending environmental calamity. But more recent evidence calls all of those fears into question.

Now another story has broken on the scene about monarch butterflies and bioengineering. It all began with a letter to the British science journal Nature describing a study concerning monarch larvae. They were fed corn pollen that had spliced into it a gene from an insect-killing soil bacterium that allows it to kill insect predators. Researchers found that larvae that ate milkweed leaves coated with the pollen consumed fewer leaves and grew more slowly than unexposed larvae. Nearly half died within four days. Headlines soon ran trumpeting the "Attack of the Killer Corn" and "Nature at Risk."

But a closer look at the study quickly reduces the fears reported in the press. The conditions in the study hardly mimic those found in nature. Researchers coated the leaves of milkweed plants so that the larvae had to eat the leaves or eat nothing at all. In the real world, lots of leaves would not have the pollen and the larvae are usually only interested in eating clean leaves.

While most corn pollen falls within the field itself, milkweed plants are found outside the field and would only have pollen that was carried by air for long distances. One researcher concluded from his studies of corn pollen, that milkweed does not grow close enough to corn fields to receive much (if any pollen). Also, corn plants only pollinate for a few days and monarch larvae only feed for a few days, meaning there may not even be any days of overlap.

Well, I think you get the point. The much-publicized fear that bioengineered corn pollen is killing monarch butterflies is not well-founded.

I'm Kerby Anderson of Probe Ministries, and that's my opinion.