A garden seed company recently sent us these seeds for a new sweet corn. The seeds were treated with Cruiser, which is thiamethoxam, a systemic neonicotinoid insecticide. They were also treated with four fungicides: azoxystrobin, carboxin, fludioxonil and mefenoxam! ALISON ROGERS

Systemic pesticides are in the plant, not on it. When we make the plant itself poisonous to predators, one has to wonder what (or who) else it’s poisoning. PHOTO: ISTOCKPHOTO

In conventional food production systems, not all pesticides remain on a plant’s exterior. Systemic pesticides are chemicals that are actually absorbed by a plant when applied to seeds, soil, or leaves. The chemicals then circulate through the plant’s tissues, killing the insects that feed on them. Use of these pesticides on food crops began in 1998, and has steadily increased during the past 10 years. Unlike with traditional insecticides, you can’t wash or peel off systemic pesticide residues.

The four main systemics used on food crops (listed below) are members of the nitroguanidine/neonicotinoid group of chemicals, which has been implicated in the mysterious colony collapse disorder that has killed millions of bees. (See our article Colony Collapse: Are Potent Pesticides Killing Honeybees?)

Imidacloprid can be applied to many vegetables (including tomatoes and leafy greens) right up to the day they’re harvested.

Thiamethoxam was first approved as a seed treatment for corn in 2002, and thiamethoxam products that are applied to the soil have since been approved for use on most vegetable and fruit crops.

-Advertisement-

Clothianidin is used as a seed treatment on canola, cereals, corn and sugar beets, and as a soil treatment for potatoes.

Dinotefuran can be applied to soil or sprayed on leafy greens, potatoes, and cucumber family crops.