Who is Eating your Tomatoes?

On Friday two shareholders stopped me with questions about our tomatoes. One person noticed a giant green caterpillar in the cherry tomatoes, and the folks were having some trouble with theirs in their yard and wanted to compare notes. I mentioned that it seemed a fairly average year so far for tomatoes….which these days, means it’s not stellar. What I mean by that is it seems as though it is nearly impossible to avoid some sort of devastating tomato disease in this region. Our tomatoes at the farm this summer started very strong with individual harvests yielding approximately 800 lbs. After a few weeks though, they have quickly reached a plateau and now we are yielding closer to 100 lbs per harvest. In addition to the onslaught of typical tomato diseases (which shoes up as brown and yellow leaves and some sunken, soft spots on the tomatoes themselves), we are also under siege from some hungry caterpillars! Yellow Striped Army Worm (photo, below left)- this critter eats both the leaves and the fruit of tomatoes. It has become more of a problem in this are in the last few years, as it has been able to overwinter and survive the warmer winter months. Tomato Horn Worm (photo, below right)- Hornworms strip leaves from plants. If a heavy infestation develops, caterpillars also feed on fruit. They feed on the surface leaving large, open scars. Hornworm damage usually begins to occur in midsummer and continues throughout the remainder of the growing season. Hornworms are often controlled by parasitic wasps (Brachonid wasps). These parasitoids lay eggs into the hornworms where their larvae feed inside, and then pupate on the backs of the hornworms. These pupal cases are seen as white projections on the back of the hornworm. If parasitized hornworms are found on the crop, we leave the larva for the next generation of beneficial wasps to emerge.

Yellow Striped Army Worm

Tomato Horn Worm

Welcome to our 2,000 new friends at the farm!

Have you noticed the beans in the you-pick section a few weeks ago had many, many holes in the leaves? Well, WE did, and we found the culprit: the Mexican Bean Beetle. After a few weeks of hand picking them off the plants, we decided we needed to bring in extra help. So we called in 2,000 helping hands! Farm apprentice Emma did some research and found a good source for a natural predator:Pediobius foveolatus (Pediobius is pronounced “pee-dee-OH-bee-us”), a parasitic wasp. We ordered 2,000 from the New Jersey Department of Agriculture and they arrived in the mail 24 hrs later. We released them at dusk on Friday night, as instructed. Don’t worry, these wasps are smaller than a fruit fly (1-3 mm) and can cause absolutely no harm to humans. The wasp lays its eggs in Mexican bean beetle larvae, then wasp larvae feed inside the bean beetle larva, kill it, and pupate inside it, forming a brownish case or ‘mummy’.  The wasps can travel a few miles, so perhaps we’ll be helping out any neighbors that may suffer from the same bean beetle pest!

Bugs on the Farm

With the mild winter I was really afraid of insect and disease pressure this year. So far…knock on wood…the insect and disease pressure has been pretty typical. This of course means we DO have all sorts of problems with insects and disease, but luckily nothing worse than what we have seen before! Although beautiful, here is an introduction to a few of my nemesis’s:

Harlequin beetles suck the juices out of the leaves of anything in the brassica family (kale, collards, broccoli, cauliflower, kohlrabi, radishes, turnips, etc). They are beautiful, but devastating. They are a problem from early summer on.

These beetles cause the leaves of plants in the cucuribitaceae family (squash, watermelon, cucumbers) to wilt and die. They can transfer a bacterium to each leaf they eat from which causes the plants to wilt and die.

These large worms burrow deep holes into tomatoes. Luckily there is a natural predator which is a parasitic wasp that injects its eggs into the worm and when they hatch the pupae eat, and kill, the worm from the inside out…gross, but good for our tomatoes!