What's bugging you? July 20, 2016

By Jim Leser


We are entering the dog days of summer where high temperatures hold steady in the 90s to 100s and the "snow" from female cottonwoods takes to the wind to settle on the ground and in my garage. With these higher temperatures you will also begin to hear cicadas sing.

These summertime songs are the mating sonnets of male cicadas. They produce these sounds by contracting two plates on their abdomen. Since much of their body is hollow, it acts like a big echo chamber. Each species has its own sound, and the temperature must be high enough before they can begin to sing.

The adult cicada is sometimes referred to as a locust as in 17-year "locusts." But this term is reserved correctly for certain kinds of migratory grasshoppers. Adults can live for several weeks but must live off their body fat as they do not have any functional mouth parts.

Female cicadas lay their eggs in slits they make in twigs. This aggressive egg laying can sometimes cause a splintering wound that can result in small twig loss. I have seen weeping willows severely damaged by this egg laying activity in Texas.

When these eggs hatch, the small nymphs drop to the ground where they develop underground, feeding on root sap of various trees and shrubs. This feeding does not cause any harm. Species in our area take two to five years to complete their development. The 17-year and 13-year periodical cicadas have much longer developmental periods and often emerge as adults in synchronized waves of incredible numbers. Lucky for us these species occur only east of the Mississippi River.

When fully developed nymphs emerge from the soil, they often climb up onto the trunks of trees or sides of buildings where their "skin" eventually splits and a soft adult emerges. These new adults need to rest while their wings and exoskeleton hardens before they can fly away. As a child, I had lots of fun collecting these empty cicada "skins." Some of my friends even tied thread around captured adult cicadas and flew them like tethered model planes.

While I can appreciate the summer songs of male cicadas, their loud, droning noise can eventually become annoying. But sound is often all you'll have as a clue to their presence. Actually finding them can be a challenge. One good thing about adult cicadas is that feathered imitations can be deadly when fly fishing for trout on waters where real cicadas are found on streamside vegetation.

Jim Leser retired to Cedaredge in 2007 after a career with Texas A&M University Extension in entomology. He is a member of the Cedaredge Tree Board and a Colorado Master Gardener.