Cicadas to remain until end of month
That loud, monotone hum coming from a clump of old trees — the reason you may have put your outdoor tennis game on hold — is the mating song of the 17-year cicada.
Until the end of June, this periodical cicada will be humming and flying through southwestern Pennsylvania, southeast Ohio and the West Virginia panhandle. The affected counties in Pennsylvania include Allegheny, Armstrong, Beaver, Butler, Clarion, Lawrence, Venango, Washington and Westmoreland.
This red-eyed creature is known as a periodical cicada (Magicicada septendecim), as it only emerges periodically — every 17 years.
Those of us residing in the above counties will meet Brood VIII, while eastern Pennsylvania residents will have to wait until 2021 to meet Brood X.
There are a total of 13 different broods, or populations, for the 17-year cicada. While there is a 13-year cicada, Pennsylvania only experiences eight different broods of the 17-year cicada. In the United States, the periodical cicada only exists east of the Great Plains.
The cicada is part of the Hemiptera order, which means it is a true bug; its genus is Magicicada and its species is arthropod.
In appearance, the cicada has red eyes with a black dorsal thorax and translucent wings with reddish orange veins. Their mouths have piercing sucking parts. The periodical cicada are typically 3/4-inch to 1.5-inch long, a bit smaller than the annual cicada. Mature females are slightly larger than the males.
When the ground temperature at about 8 inches in depth reaches 64 degrees Fahrenheit, the cicada nymphs emerge in the evening. The nymphs then find a suitable location on nearby vegetation to complete their transformation into adults.
They molt, then spend about six days waiting for their exoskeletons to harden. Their sole purpose as adults is to reproduce.
The males use their tymbals to produce their mating call. Most mating occurs in “chorus trees.” The decibel level of a chorus of male cicadas can reach 100 decibels, which is a similar noise level as riding a motorcycle or operating a hand-held drill.
The male cicada has a separate courtship song when approaching a female. The female, in turn, responds with a “wing-flick” that attracts the males for mating.
A female uses a sawlike devise that extends from her abdomen to saw into the stems of woody plants to drop eggs in rows. She will lay as many as 600 eggs over the course of her four- to six-week life span.By early July, the adults will be dead, and the eggs will have hatched into nymphs that fall to the ground and bury themselves for 17 years. While buried underground, the nymphs live about 2 feet from the surface and feed on the juices of plant roots.As they grow, the nymphs move deeper underground to feed on larger roots. They undergo five instar, or developmental stages, during their underground life.After 17 years of growing underground, the nymphs emerge en masse, with as many as 1.5 million insects per acre.This survival trait of mass emergence is known as predator satiation, as several predators will consume the cicadas in large numbers. Cicada predators include birds, rodents, fish, insects and humans.If you are inclined to eat cicadas, remember that they are arthropods and can cause an allergic reaction in people with shellfish allergies.Chefs recommend removing the wings and legs for easier consumption.Entomologists note that cicadas might be contaminated with mercury or pesticides from having lived underground for extended periods of time.Discourage your pets from eating cicadas, as their exoskeletons could be a choking hazard.The only damage to plant life cause by cicadas is from the slits in woody stems made by egg-laying females. Affected woody stems might have leaves that wither and die, and damaged twigs could break off and drop onto the ground.Fruit and nut trees might experience heavy pruning losses from high populations of cicadas damaging the woody stems. Nonchemical management of cicadas is to allow their natural predators to devour them.Small trees can be covered with a mesh cloth to prevent females from egg laying. Gardeners may want to delay tree planting during cicada season.Cicadas will be with us for a short period of time this summer, and we will see and hear them again in 17 years.Polly Burkhard is a Penn State Extension Master Gardener, Class of 2019.
