I have been using UV light for years to trap insects and look for other invertebrates such as scorpions. I recently decided to use UV light to look for pests in the garden. When scanning the tomato plants they lit up like Christmas trees with tomato hornworms glowing a bright blue-green in the light. I was able to remove over 20 of them in five minutes; because of the dense growth of the plants none of these were easily visible in daylight.
