If you live in the eastern or southern parts of the United States, there’s little doubt that you’re familiar with the cicada – the only bug that can be heard above the din of a noisy lawn mower. So do cicadas damage plants? Experts offer mixed opinions on the subject, but it is generally accepted that cicada bugs in the garden are mostly harmless. However, they may cause damage – usually minor – to young or newly transplanted trees, or to trees that are already stressed and less than healthy.
What is a Periodic Cicada?
Periodic cicada is a specific species that appears like clockwork every 13 or 17 years. These are the pests that can harm oaks and other deciduous trees, usually when the females lay eggs in the young shoots. However, because periodic cicada emergence is spaced so far apart, healthy trees are able to rebound with little ill effect.
Some trees, including mesquite, may lose branches when the females make small slits where she deposits her eggs. Experts at Arizona’s Maricopa County Cooperative Extension say that no control is necessary and that this process should be considered a healthy, all-natural form of pruning.
Cicada Control in Gardens
If you’re overwhelmed by the hordes of cicadas, or if you think they are damaging a prized tree or shrub, you can take steps to minimize the damage. One easy way is to protect the tree with mosquito netting or old curtains as soon as the invasion gets serious.
Resist the temptation to blast the pests with insecticide. The chemicals won’t make a dent in the cicada population, but will kill birds and beneficial insects that work hard to control the pests. Don’t be squeamish if you want to keep cicadas in check; even snakes, lizards and rodents do their part by chowing down on the protein-rich bugs.
During the invasion, you may notice cicada killer wasps. These large wasps, which measure 1.5-2 inches (3-5 cm.) in length, are definitely intimidating, but they should be encouraged if you want to reduce the cicada population. The male cicada killer wasps are especially scary because they tend to be aggressive, flying at people or crashing into windows. However, male wasps cannot sting.
On the other hand, females are capable of stinging, but they aren’t aggressive towards people. Their sting is reserved for cicadas, and you may notice female wasps flying around with a paralyzed cicada in their jaws. Usually, cicada killer wasps are present only when cicadas are active.