This is my first year growing tomatoes but here is what I have learned from the forum...you can hand pick off the large adults if you are brave and either drown them in a bucket of soapy water or remove them to a different location well away from your plants. Yeah, not me. I cut them in half with my clippers. I am terrified of bugs and refuse to touch them. That is what my husband is for. I would be cautious to think that they are the least of your pest concerns. A full sized bad boy can take out an entire tomato plant overnight. They eat a lot FAST and they reproduce almost as bad as bunnies. I spray a BT (bacillus thuringiensis) solution every 7 to 10 days. It is very safe for you and your plants and has been working wonders. I would suggest using some sort of spray if you do not have a good supply of parasatizing wasps (like me). As for the life cycle, I do not know exacts. I would try googling that if you can't find the answer here.

Yes they do come back every year. No they don't overwinter. These are actually tobacco hornworms. Tomato hornworms have a black horn. Don't be afraid of the horn. They do not hurt unless you step on one barefooted. BT works but I don't get enough to worry about that.

As ashley stated they can devastate your plants quickly so you should be very concerned about getting a handle on them. BT is a good suggestion, and don't be worried about picking them off and throwing them in a bucket of soapy water, they won't hurt you despite their looks.

A few years ago I was looking out the window at the tomatoes in the garden when I saw a roadrunner furiously pecking at the plants. At first I thought that he/she was eating the tomatoes themselves until I saw a big green worm in his/her beak. All I could do was to smile and thank him/her.

Greg
Nevada

I've been growing tomato for around two decades in the Bay Area and has never seen tomato hornworm before this year.

Last week I hand picked five larvaes two inches long. Of my six varieties of tomato, they only favor BrandyWine (the only kind grew from store bought seedlings). All other tomato I planted from seeds a foot away are not bothered. Since I don't use any pesticide, I wasn't sure what to do. So I placed small dishes of water on the trellis hoping to attract bird better.

Like Ashley said, they have big appetite. Now I check for their droppings every day and haven't found any worm this week. I'm sure this is not the end of the battle. Hopefully someone else knows of a way to control these things.

People, you have to look for the single, round pearly eggs laid usually on the lower but sometimes the upper surfaces of the leaves! Also, look for the teensy little caterpillars that hatch from those little eggs. You're waiting way too long to get rid of these pests.

Here is a link that might be useful: Click here

Another organic method of control (besides BT which is excellent) is to plant Borage, a herb, next to your tomatoes. It is a beautiful herb and it repels tomato worm. The leaves can be picked for soups, salads, curries fish, chicken and yogurt. They have a taste similar to cucumber. Bees also love Borage for the nectar so it has multiple benefits. Anyway, just another idea.

If you do plant be careful since it self seeds easily. You could have a garden full of Borage if you do not collect or discard the seeds. Also do not till in the flower heads or you will have a bunch of unwanted borage next season.

Thanks amlinde! I have never heard of borage. I just looked it up and the flowers are beautiful. I love the idea of a beautiful plant doing double duty: protecting my tomatoes and is edible. I will definitely be looking into that next year.

Borage flowers are somewhat insignificant. They are small compared to the rest of the plant, at least the ones I had were. I'm not growing it this year and have less hornworm problems.