Category Archives: Gardening

Distinguishing tobacco and tomato hornworm caterpillars

After agonizing over the identification of hornworm larvae for years, I’ve developed two tricks that I’d like to share. Tobacco hornworm (Manduca sexta) caterpillars have stripes (seven of them), so remember that by thinking of Lucky Strikes cigarettes. Horn is usually red or red-tipped, like a cigarette. Also, tobacco gives you dark teeth and lungs … and tobacco hornworms have black shadows on their stripes. Tomato hornworms (Manduca quinquemaculata) have eight chevrons (Vs), which you can remember by thinking of V8 juice, which is primarily tomato juice. Here’s the graphic you can share with friends who might have it wrong:

Photographs of tobacco and tomato hornworm caterpillars

If you can, please spread the word … most of the tens of thousands of tobacco hornworm photographs on the internet are misidentified as tomato hornworms. Even Wikipedia page for tomato hornworm shows tobacco hornworm larvae (I’m working on it …). The problem is that tobacco hornworm eats tomatoes, and people with fancy cameras grow a lot of tomatoes.

For people living in Hawaii, please note that the above doesn’t include Manduca blackburni, which is closely related to tomato hornworm.

Photograph of tomato hornworm from Amanda Hill.

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Minor victory in my war against yam labeling fraud

In my futile quest to convince people that sweet potatoes shouldn’t be called yams (which are unrelated plants), I discovered that one can actually report vendors who label sweet potatoes as yams. So, for giggles, I reported Giant Foods to the USDA’s Misbranding and Misrepresentation Office. Below is a photograph I took in November of their organic sweet potatoes:

giant-sweet-potato-05 (1)

And now in all of their stores (that I’ve checked), they sell sweet potatoes labeled as sweet potatoes:

Nature's Promise sweet potato at Giant

It might be a small victory, but Giant Foods is giant, so I’m pleased. If you want to know more about my futile war, please see my page on Yams versus Sweet Potatoes. If you want to make your own report, just visit the above USDA site and send the contact person a photograph of the label along with store contact information. They’ll do the rest, and apparently in a persuasive way.

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Open letter to produce managers re: yams

Dear Produce Manager,

If you want to sell more orange-fleshed sweet potatoes, craft your labels with “yams” in parentheses, like this:

Sweet potatoes (“yams”)

Because you are a produce manager, you undoubtedly know that a yam is a completely unrelated thing, so using quotation marks will indicate to ignorant shoppers that you are not actually selling yams. As you also surely know, “yam” is regional slang used by some (generally older folks) to refer to a sweet potato that has orange flesh. But if you only have “yams” on label, some shoppers might get flustered and leave for another store that labels sweet potatoes as “sweet potatoes.” Still others are looking for a specific variety of orange-fleshed sweet potato (Beauregard, Jewel, etc.), so list that, too. E.g.,

‘Beauregard’ sweet potatoes (“yams”)

That’s a lot of text, but different varieties are good for different recipes, and some of your customers are over-educated foodies who care deeply about such details. Ideally, cut one in half and cover in plastic wrap to convince skeptical shoppers that it does, indeed, have orange flesh.

Colin Purrington

These are sweet potatoes

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