Garden Q&A: Click beetles and the curling geranium leaves
By Ellen Nibali
Jul 23, 2020 at 7:00 AM
This googly-eyed bug landed on my shirt, then immediately flew off. Hard to be scared of such a funny looking bug, but he seemed huge! Thoughts?
The big-eyed click beetle is straight out of central casting for backyard zoo. Coming in at up to 2″ long, with false eye spots to intimidate predators, the native Alaus oculatus is one of the largest click beetle species.
Also known as snapping beetles, spring beetles and skipjacks, most click beetles are smaller and dull-colored but still impressive because of a startling self-catapulting mechanism. When frightened, their specialized “spine” pops into a notch, propelling the beetle into the air up to several inches. You can hear the ‘click’ and feel it if you hold on. Flipping into the air is also handy when the beetle finds itself upside down and must right itself, which can take multiple flips.
The larvae (immatures) are called wireworms and typically feed on dead, decaying material, but a few species are potato and strawberry pests. The big-eyed click beetle is neither. It is a predator consuming insects, insect eggs and small invertebrates, so it’s a good guy plus fun for kids (and adults) to encounter.
My potted geranium showed curling leaves and soil felt dry, so I gave it a thorough watering. It has been raining, so soil is still damp, but leaves are still curled. Now I see dry brown spots and every now and then a yellow leaf at the base. It’s still blooming regularly on my deck in full sun.
Geraniums are resilient and can tolerate a common fungus, known as botrytis or gray mold. It is encouraged by wet leaves.
Pick off yellowed, spotted or brown leaves and dispose of them in the trash to reduce infectious material. Water plants at the base. Some of the yellow leaves are probably old ones, a result of normal dieback and death.
University of Maryland Extension’s Home and Garden Information Center offers free gardening and pest information at extension.umd.edu/hgic. Click “Ask Maryland’s Gardening Experts” to send questions and photos.