The name itself has been known to strike fear in the hearts of gardeners near and far. Given the fact they seem to show up without warning, large groups almost materializing overnight, their victims can feel like they have been struck with a plague right out of the Bible! One day you are watering your beautiful, flawless tomato plants and the next day you stroll to your garden to find half eaten fruits and wilting leaves. What adds to the frustration and makes you feel totally helpless? You can NEVER SEE THE CULPRITS!! Luckily we have a little cheat code that will make getting rid of these pesky bugs a lot easier.
What are Hornworms?
Long time gardeners will be familiar with these green caterpillar pests. There are two main species that can be found in most regions of the U.S. and Southern Canada: tomato hornworms and tobacco hornworms. Don’t let their names fool you though, both will ruin your Tomato plants without a problem. These worms also feed on other common garden plants such as eggplants, peppers, tobacco and potatoes.
The problem is that the Hornworm blends in easily with their surroundings / favorite food – your tomato plants. Their near perfect camouflage makes hand picking a large group seem impossible, even when one is found there are many more hiding right in plain sight waiting to continue ravaging your plants when your back is turned. There has got to be a better solution right? I mean, when adversity hits, humans turn it around and make it work in the end, so what is the solution for the hornworms?!
How to Find Hornworms on your Plants?
Many suggest the easiest way to find Hornworms is to search for their droppings towards the top of the plant, where they tend to start feeding first. Following these dark green or black droppings that appear wet on the topside of the leaves will lead you to the culprits that tend to sit on the underside of the foliage. This may help you find some, but this is still a lot of work for larger gardens and is still very easy to miss a few with their world class camouflage.
The answer to finding these pests the fastest is actually Ultra Violet Black lighting! The Tomato Hornworm may be superior in the daylight blending in with the plants foliage but at night, under the right lighting they glow like they are radioactive! That’s right friends, light them up at night and they have nowhere to hide!
We field tested this theory using our 395 nanometer UV strip. With a battery powered section of the strip we took this out at night and could easily locate hornworms that glowed green across the dark green foliage.
When hand-picking Hornworms you have a few options on what to do with them:
- Feed them to your Chickens (don’t have any? Jump to option 2)
- Drop them in a bucket of soapy water mix. (Too boring? Jump to option 3)
- Squish the suckers (Too violent? Jump back up to Option 2)
Hornworms can show up fast and many eggs typically hatch in one spot so please remember this is a nightly routine if you want to keep your tomatoes worm-free and healthy!
How to Build Your Own Hornworm Sniping Black Light
Buy a section of our High Density Ultra Violet Strip Light. This outputs about 395nm which is in the UV-A spectrum range – qualifying as a black light. The strip comes with adhesive backing and a 2.1mm female barrel plug connector on one end.
You may use your own 12V power source or use this 8AA battery pack from us which is the only portable power option we have for this strip light. Choose the 8AA holder with plug so that you have a male power plug to go into the strip light. The pack has a toggle switch so that you can turn the device on and off once it is connected.
You may also purchase a section of our mounting track if you would like to house the strip in something. You may also choose to wrap the length of strip around a stick or something you already have at home. We ended up using a 9” section of strip and cut down the track to fit the strip so we had a small and convenient hornworm finder. The design part is up to you, build it how you would like to use it.
IF you just want a stand alone kit to buy than you can purchase this Battery powered LED Strip kit. This will come with a 20″ section of strip and the 8-cell AA battery pack. Choose the high density and UV output options.
Once your light is up and running use outside after dark to illuminate the hornworms on your plants. This will make the hand-picking method much more efficient.
We let a local farmer use our unit and the results floored her. Before the light was used one, two, maybe three hornworms were found and removed daily. After the light was given to her over 20 were hand picked in a single 30 minute scan! And if that doesn’t make your skin crawl, she picked 17 MORE off the following night! Point in fact, the UV light worked like magic, and she hasn’t found more than one after the initial scans. Tomatoes stopped coming up half eaten, the leaves grew back and we now have one very satisfied tomato farmer.
The UV light strip can also be used for other insects, from poisonous scorpions to disgusting bedbugs, and can be used in the detection of bodily fluids (yuck!) like blood if you are into forensics as a hobby!