Late in the summer the tomato plants begin to yield their fruit. Unfortunately for me, my small vegetable garden once again has been overtaken by the tomato plants that seem to self seed each year. I find them sprouting from my potted plants and garden because I do use my rich composted soil for my container plants too.
For the past few years I have had problems with my tomato plants. In the past I had to fight off a white fly invasion. I tried everything from chemical solutions to organic ones. I even purchased thousands of Lady Bugs which I read feast on the white flies, but alas that didn’t work either. Last year I tried a new approach and that was to border my garden with marigolds and nasturtiums because it seems that the white flies don’t seem to like the odor from these flowering annuals.
This year, there are no leaf insects in my garden, the tomato plants are once again taking charge and pushing out the eggplants, the string beans, the peppers and the zucchini plant which is huge. I don’t think I will plant zucchini next year, their leaves are huge and they spread and take up too much real estate for the small yield we get.
Beneficial Insects in Your Garden
We all know about the common ones, the ladybug, everyone’s cute little friend. We were all taught the song, Lady bug, lady bug, fly away when we were children and everyone knows they eat harmful insects in the garden. We also know that earthworms are good for your garden, they can convert large pieces of organic matter into rich humus, thus improving soil fertility. I use red wiggler worms to produce rich castings (compost) that I can use in my home and garden, it is the best organic fertilizer you can use…read more in my articles on composting with worms.
Bees of course are important to our food sources because they pollinate our plants which encourages them to flower and bare fruit, but what other insects are beneficial? This article is going to introduce one more to you…
The Tomato Hornworm
Today I discovered a large green tomato hornworm in my garden on one of my tomato plants. This hornworm is actually a 5 spotted moth in one of the early stages of development. For anyone growing tomato’s this little guy can eat through a tomato plant in days, so when you find them you want to remove kill them. However, you will find that this hornworm can also be a friend and some websites even sell them.
The photo you see on the top of this article is a Tomato Hornworm in my garden. You can see it is covered with a number of white eggs, this caterpillar has been parasitized by an Adult female wasp. They will ovipositing their eggs into their hosts bodies as this one has done to this Hornworm. The females of some parasitoid species also insert secretory products (combinations that may include polydnaviruses, ovarian proteins, and venom) that protect the egg from the immune system of the host. Once a host of a parasitoid that expresses polydnavirus particles has been parasitised, the virus that accompanied the egg during oviposition, infects the cells of the host in ways that benefit the parasitoid.
At first I thought they were somehow part of the caterpillar…but that didn’t make sense since the hornworm is one of the early stages of the Five Spotted Hawk Moth which of course is not a beneficial insect in your garden or home (unless you see the white eggs on it). Their normal life cycle lasts around three weeks at 75°F and as little as two weeks at 85°F. So do we remove them from our plants, the simple answer is yes if you see them eating all of your tomato plants, but the answer is also a big NO if you see them with the white eggs on its back. These are actually the Braconid Wasp which is a beneficial insect for your garden.
The Braconidae is a large family of parasitoid wasps. They are often black-brown (sometimes with reddish markings), though some species exhibit striking coloration and patterns. Adult braconid wasps consumer flower nectar and pollen. They provide effective caterpilllar control, aphid control and more. Braconids lay eggs on numerous pest species, such as caterpillars (including cabbage worms and tomato hornworms), aphids, flies, beetle larvae, leaf miners and some true bugs. A female braconid wasp can lay from 50 to 200 eggs, so this beneficial can have significant positive effects in the garden. As the wasp larvae feed inside their hosts, they weaken them and make them incapable of reproducing. To read more about this beneficial little wasp click here.
I have included a number of videos below that will give you more information on the Tomato Hornworm and the Braconid Wasp that I think you will find fascinating. Remember, not all insects are bad and it is important to encourage the good ones to stick around and discourage or remove the bad ones when we find them.
With a pair of gloves in hand it is easier to simply remove a caterpillar that is doing damage to your plants then to spray your plants with harmful chemicals. So look for these little guys in your garden, remove the bad ones and by all means take advantage of the good ones.
Videos On The Hornworm and the Wasp