Q: This fall I found I had holes in my tomatoes. I cut some open and there were some kind of brown hard stuff in the fruit. Any idea what they are?
A: The signs indicate tomato fruitworm (Helicoverpa zea) damage. These insects are fairly common and also known as corn earworms and cotton bollworms, depending on the crop where they are found. The eggs are laid on the plant and the larvae bore into the fruit where they can stay until they complete their development and drop to the soil to pupate. The brown stuff is probably frass (caterpillar poop). These insects are difficult to manage once inside the fruit so it is best to catch them before they enter and/or dispose of infested fruit before they have a chance to emerge. Lima beans can be used as a trap crop because they prefer them to tomatoes. There are also pheromone traps available to monitor when the adults are flying so you can tell when to start looking.
Peter L. Warren is the urban horticulture agent for the Pima County Cooperative Extension and the University of Arizona. Email questions and photos to tucsongardensage@gmail.com
