Hornworm horrors
I got a phone call recently and the first thing the caller asked was, “How are your tomato plants doing?” Gardeners pride themselves on their tomatoes. I pore over seed catalogs in winter looking for varieties I’ve never grown before, and plant the seeds in pots in late winter. I hover over and stare at the pots of soil seven or eight times a day because this of course makes the seeds sprout faster.
Then after a week or so the plants start popping through and I am again assured no one grows tomatoes better than I do. Six weeks later they are flourishing in the garden needing trellising or cages because it is evident no one grows tomatoes better than me.
But allow me to revisit a tragic moment from my past. Along comes a mid-summer day and I saunter to the resplendent tomato department of the garden only to find – oh woe is me! – bare tomato stems dangling in a summer breeze! No leaves! I raised these plants from pups! Where’d the leaves go! And then I see the gnarly green perpetrator.
As I am grieving over the ravaged remains of my tomato vines, it might not matter that there are two possible culprits: tomato hornworms or tobacco hornworms. They are called hornworms because at their posterior tip (hiney) they have a horn of sorts. The tomato hornworm has a black horn and Mr. and Mrs. tobacco hornworn have red horns.
Also, tobacco hornworms have parallel white stripes along the body and the tomato cousins have V-shaped markings.
Tomato hornworms are less prevalent in the Southeast, so what we anguish over in this part of Arkansas are probably tobacco hornworms. Does it really matter what you call it if the damage is the same? It won’t help to call out the secret police or delay the election if the damage has been done.
Both hornworms are the larvae of species of moths with local names of either hawk moths, hummingbird moths or sphinx moths. A gardener assiduously tilling garden beds in spring might encounter just below the surface a reddish-brown cocoon-looking pupa. Inside there is a moth developing. It will emerge in late spring and lay maybe 2000 tiny eggs on the underside of leaves of tomato family plants during the night. Within a week, the larvae emerge and trouble begins, and there might be two generations per season.
There are terrible horrible poisons crafted by ingenious chemists which will kill hornworms (plus a hundred useful things), but everybody is different, and I prefer to find the cursed intruders and take full responsibility for what happens next.
Bacillus thurengiensis (Bt) is an organic insecticide which will kill them, but the larvae must ingest it for Bt to work and Bt washes off, so several applications might be required. Brachonid wasps (if they’re around) kill hornworms by laying parasitic eggs on them, but the best strategy is to be there. I use gloves when I pull them off because they cling tightly. They don’t swim, so, you know, a bucket of water, etc. Chickens, guineas or your pet snake will make good use of hornworms.
I throw them into the woods. Is that terrible? Maybe they will learn to like oak leaves and stay out of my garden. It could happen.
Also, once you or someone you know finds a hornworm, you remain on full alert until the end of the season. I feel like I should go check now. Again. And just because you find one, you don’t know if there are any others, so you keep watching. Any more leaves gone? Watch for the dark poop balls.
An effective way to avoid the hornworm drama is simple garden diligence – plenty of tilling after the season and before you plant again.