As we make the transition from spring into summer, the wildflowers are fading, flowering trees and shrubs are ablaze in color, and the mosquitoes, deer flies, and other insects are making their presence known in one way or the other. We are all too familiar with the biting and blood sucking insects that cause us so much irritation, but there is another insect that can almost drive people to insanity due to its constant-saw like droning; the cicadae. There are 170 species of cicadas in North America, 2000 in the world, and they inhabit every continent except Antarctica. There are three types of cicadas, the periodical, photo-periodical, and the annual or commonly known as dog day cicadas. There are seven species of cicadas in the genus Magicicada, called the periodical cicadas. They are divided into groups called Broods. On the East coast Brood II has recently emerged. In 2016 we will once again be hearing the emergence of Brood V. They are distinguished by bright red/orange eyes and black bodies with orange markings. These cicadas are only found in Eastern North America including parts of Ohio. The smaller periodical cicada, completes its life cycle in either 13 or 17 years, and emerges in large numbers within large geographical areas. In 1956 the XIII brood emerged and estimates were upwards of 1,500,000 cicadas per acre. Adults emerge from April through July, depending upon species and locality.
The annual or dog day cicadae, genus Tibicen, vary in size and color according to species. All have prominent bulging eyes and semi-transparent wings held roof-like over their large bodies. The larger species are about 1-5/8 inch long and 1/2-inch wide with brown or green, black and white body markings.
The life cycle of the cicadae is very simple. The males make this sound by flexing their tymbals, which are drum-like organs found in their abdomens. Small muscles rapidly pull the tymbals in and out of shape like a child’s click-toy. The sound is intensifed by the cicada’s mostly hollow abdomen. Records in Floridia indicate that some cicadas can produce sounds of between 108-120 decibels. The pain threshold for humans is 120-130 decibels. Any sound above 85 decibels can cause hearing loss, and the loss is related both to the power of the sound as well as the length of exposure. Just remember, human speech is only registered at about 25-35 decibels. Female cicadas also make a sound by flicking their wings, but it isn’t the same as intensity as the males. After mating with the male, the female insert clusters of eggs into groves at the ends of twigs and small branches using a saw-like egg laying structure called an ovipositor. These grooves can kill small branches. When the branches die and leave turn brown, it is called flagging, a common sight in early August after the emergence of the adult brood. In 6 to 7 weeks, small nymphs hatch from the eggs and drop to the ground. They burrow into the soil, seeking tree roots. They suck fluids from the roots for food, but this does not harm the tree in any way. As they molt through several stages of growth called instars, they may burrow several feet down.
After the long 2 to 17 years, cicadas emerge from the ground as nymphs. Nymphs climb the nearest available tree, and begin to shed their nymph exoskeleton. Free of their old skin, their wings will inflate with fluid and their new skin can harden. Once their new wings and body are ready, they can begin their brief adult life. Adults can live for 5 to 6 weeks. Adult cicadas spend their time in trees looking for a mate.
Cicadas serve a number of purposes. They aid their host trees by aerating the soil when they emerge, as well as trimming weaker branches then they lay their eggs. They also form a vital link in the food chain between trees and literally hundreds of carnivores and omnivores, including: squirrels, birds, toads, raccoons, possums, other insects, and people.
Cicadas don’t bite or sting so they don’t pose any danger to humans. They do have prickly feet and a beak which can pinch or scratch. However, they can damage small trees and shrubs. In order to protect your newly-planted tree or shrub from damage you can wrap netting around them, spray them off with a hose, or pick them off with your hand. Because adult cicadas don’t eat, don’t bother with pesticides. You will be wasting your time and money, plus potentially harming other useful insects. The only predator of the adult cicadae is the cicadae killer, a large wasp which injects a venom into the cicadae which paralysis it, allowing the wasp to take it back to its hole and eat it.
DID YOU KNOW
“Cats and dogs should not be allowed to eat Cicadas”
Animal health experts are warning people living along the East Coast of the US not to let their pets eat too many of the billions of cicadas that are emerging across the region. Every 17 years at this time, like clockwork, Brood 2 cicadas crawl out of the ground from N. Carolina to New England. “As tempting as bugs may be, the outer skeleton of the cicada contains a tough material called chitin that is problematic when eaten in large quantities,” cautioned Brian Collins, of the Cornell University Hospital for Animals. He said that chitin is also found in lobster shells, and eating too much could cause cats and dogs to experience vomiting or constipation, which would require a visit to the vet.
From an article the Plain Dealer May 8, 2013
Other Nearby Nature
Fat Muckett Canoe Cruise – Sunday, June 2 (10 am-1 pm)
Paddle with naturalist Bob Faber on the serene upper Cuyahoga River near Burton. The slow moving state scenic river winds through extensive wetlands and bottomland forests near Russell Park in Geauga County. Wildlife of the area includes river otters, beaver, mink, sandhill cranes, bald eagles, prothonotary warblers and the extremely rare jewel wing and the elusive fat musket. Canoe or kayak rental is $18 per person or if you have your own canoe/kayak $8 ($3 discount per person for members of Friends of the Field Station). Register by phone (330.569.6003) or email (email@example.com). Length: 3 miles.