By James A. Bethke.
While working to fix an irrigation line in my yard I noticed that one of my window screens was slightly damaged. Upon closer inspection, I noticed that there were eggs thrust into the screen (Fig. 1). I usually see these eggs laid sequentially and slightly overlapping each other along a stem on just about any plant in my yard. They are Katydid eggs. Katydids are not really a garden pest. They move from plant to plant testing the tissues and often feed on the new growth. They don’t defoliate plants or areas of a plant. They can, however, be a pest of citrus orchards, especially of young citrus trees because they eat the new growth and the peel of young oranges. Their fruit nibbling creates sunken areas in the peel as the fruit continues to develop rendering the fruit unsalable.
The common true Katydid (Orthoptera: Tettigoniidae) is active at night, (nocturnal), looks like a bright green leaf (Fig. 2) and makes a clicking sound high in trees at night, which some say sound like “katy-did katy-didn’t” repeated over and over. Katydids are related to crickets but are often called long-horned grasshoppers due to their very long antenna. They eat leaves, flowers, stems, and fruit of many different plants. Interestingly, there are a few species of katydids that are ferocious predators and eat other insects.
Katydids are cryptically colored. They are known for their mimicry and camouflage, which allows them to avoid predation by blending in with their environment. Their antenna exceed their body length (hence the name, long horned grasshoppers), and hatchlings are almost all antenna.
As an advisor, I have been asked to identify their young and their eggs in photos sent to me in the past. I find them a fascinating insect that exhibit the brightest green possible. They lose that bright green when pinned in a collection. Otherwise, I could prominently display their amazing colors right in my personal collection. I do not believe there is a reason to control these insects as garden pests, but rather I think you should observe and appreciate them.
Fig 1. Katydid eggs deposited on a window screen.
Fig 2. Adult Katydid male on a patio chair in the backyard.