Cicadas are fascinating insects known for their distinctive sounds. While often confused with locusts, cicadas are a separate group of insects. Unlike locusts, which are a type of grasshopper that can swarm and devastate crops, cicadas are generally harmless to humans and mature plants. Cicadas are indeed present in Oregon, though their presence differs significantly from the large, synchronized emergences seen in other parts of the United States.
Cicada Presence in Oregon
Cicadas are present in Oregon, but their presence differs from the publicized periodical cicada events in the eastern and midwestern U.S. Oregon hosts annual cicadas, meaning some adults emerge every year. This contrasts with periodical cicadas, which emerge in massive, synchronized broods every 13 or 17 years. These large emergences, characterized by overwhelming numbers and loud choruses, are not found in Oregon.
Oregon’s cicadas emerge in lower densities and are generally not as loud as those found elsewhere. While a few individuals might be seen or heard each summer, they do not appear in the “nuisance levels” sometimes experienced during periodical cicada events.
Oregon’s Cicada Species
Oregon is home to approximately 30 cicada species across three main genera. The most common genus is Okanagana, which includes 23 of the state’s species. These Okanagana species produce the buzzing sounds associated with cicadas.
Other genera include Platypedia (five species) and Neoplatypedia (two species). Unlike the buzzing Okanagana, these species do not produce sound using tymbals. Instead, they attract mates by making clicking sounds with their wings. Examples include Okanagana oregona, Okanagana bella (Mountain Cicada), and Platypedia similis.
When and Where Cicadas Appear in Oregon
Cicadas in Oregon typically emerge during the warmer months, with activity observed from July through August. Their emergence is often triggered when soil temperatures reach approximately 64°F, usually in late spring or early summer.
Nymphs of Oregon’s annual cicadas spend an estimated two to five years underground, feeding on the sap from tree roots. When ready to emerge, mature nymphs crawl out of the ground, often climbing nearby plants or tree trunks, to undergo their final molt into winged adults.
Cicadas generally prefer forested and wooded areas, as well as parks, due to the presence of trees that support their life cycle. They are commonly found in areas with well-drained soil. Some reports indicate their presence in the Portland metro area and southern Willamette Valley, including locations like Hillsboro and Eugene.
Interacting with Oregon’s Cicadas
Encountering cicadas in Oregon typically involves hearing their characteristic sounds, which are primarily the mating calls of male cicadas. These sounds can be quite loud, as male cicadas use specialized structures called tymbals on their abdomen to generate their calls.
Cicadas are not harmful to humans or pets. They do not bite or sting, and they are not considered pests that pose a significant threat to mature trees. Female cicadas lay their eggs in small slits they create in the slender twigs of trees and woody shrubs. While this can cause some twigs to wither and die, a phenomenon known as “flagging,” mature, healthy trees can typically withstand this without lasting damage. Young trees, however, may be more susceptible to damage if they experience heavy egg-laying. Cicadas also play a role in the ecosystem, serving as a food source for various predators and contributing to soil aeration and nutrient cycling as their decaying bodies enrich the earth.