Tag Archives: distinguishing

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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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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Sweet potato flesh can reduce yam confusion

So I have a silly, futile goal of reducing the confusion over sweet potatoes and yams in the United States. If you are a grocery store manager and are on board with this silly, futile goal, please consider displaying the flesh inside the different sweet potato varieties you sell. Doing that will reduce reliance on the strange habit of calling orange-fleshed sweet potatoes “yams.” You can easily show the insides of your sweet potatoes by chopping one in half and wrapping the cut end in plastic wrap, then placing back into the display shelf — you can even use a Sharpie to write stuff on the plastic (I’ve never seen this done … but I’m sure it would work). Or you can make signage that has a photograph of flesh. If you also add some thoughts on how to use them in cooking, even better. Below are two examples of ‘Nancy Hall’ and ‘Beauregard’ sweet potatoes that I cooked over the weekend.

Labels for sweet potatoesNote that the word “yam” does not appear on the sign. If you are the type that says, “What?? You idiot. That sure looks like a yam to me!” … please have look over my “Yams versus sweet potatoes” page. It probably won’t change your opinion, but you’ll at least know what a yam looks like.

On a side note, my ‘Nancy Hall’ sweet potatoes turned out great. I partially cooked them in the oven (coat with bacon fat first) and then sauteed the diced flesh with butter and hickory bark syrup. I used the ‘Beauregard’ to make biscuits. It turns out that biscuits are good with Chessmen cookie butter. Just saying.

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