Species Spotlight

What's the buzzing all about?

One of the most commonly asked questions in the summer is "what is that noise?"  It's usually a walk down the McCoy trail that prompts such question. That's because as you stroll the trails around the visitor center there's often a loud buzzing sound coming from the vegetation (much like the sound a rattlesnake makes, only louder!).  Well, the short answer to the question is "Cicadas."

A cicada is an insect in the order Hemiptera and there are over 2500 species in the world.  There are roughly 200 species in the United States and 22 species have been documented in San Diego County, 4 of which are coastal species (from Michael A. Wall, Ph.D., SDNHM).  Rarely seen, and more commonly heard, cicadas are basically harmless.  The most "famous" of all cicadas are the 3 species that emerge every 13-17 years in large swarms in the Eastern U.S.  In San Diego, yearly emergences are much more regular.

Size: Cicadas generally range in size from 1-2"

Habitat: Cicadas generally prefer temperate to tropical environments and are found in booth tree and shrub habitats.

Diet: Cicadas suck xylem or "juice" from roots and above ground vegetation.

Life cycle:  A cicada begins its life as a nymph that hatches from an egg laid on a branch of vegetation. Immediately it falls to the ground.  There, it buries itself in the soil and lives off the roots as it develops underground.  Depending on the species, it can live underground as little as 2 years or as many as 17 years (see above).  It is the final stage of their life that we are most aware of.  After the nymph emerges, it crawls up the plants and sheds its skin finally becoming an adult, the shortest stage of its life.  That's when the buzzing begins.  Males call or sing attracting females.  The buzzing is so loud that it's difficult to ignore.  Impregnated females then lay their eggs on the vegetation, perpetuating the cycle. Adults generally live only 4-6 weeks following emergence.

Predators: Birds (most common); also

- wasps and beetles.

San Diego Cicada Species: