Sounds of Summer - Cicada and other insects
I was born and raised in Big Spring, but my military family had called Pennsylvania home until that time. I remember my mom telling me a story of the first summer the family was here. My sister came running into the house announcing that there were rattlesnakes in the trees! What she had heard were the songs of the Cicada and the rattle of them flying from one tree to the next.
Much has been in the national news lately over the 17-year Cicada emerging in the Northern and Eastern states. Cicada have a unique life cycle, living only a short amount of time above ground, about 5-6 weeks. After mating, the female lays her eggs among tree branches then dies. Upon hatching, the offspring — known as nymphs — drop to the ground and bury themselves. They stay underground, drinking liquids from roots until they reach maturity to emerge to start the cycle for a new generation. And “generation” is a good term as, depending on the species, this process takes three to 17 years. Most of the Cicada in West Texas are the 13-year species, but you will see emergence yearly as some overlap or stagger the generations. Of course, what you see first are the temporary exoskeletons that are left from the nymphs splitting their exoskeletons and emerging as a winged adult. Then we get to hear them!
Male Cicadas are well known for their song, which is used to attract females. The sound is produced by vibrating membranes called tymbal on the sides of their abdomen. Females do not sing. The song of the Cicada can reach over 100 decibels and can be heard from one mile away. A secondary use of the Cicada song is self-defense. When a Cicada is captured by a bird it will emit a high-pitched shrill or rattle loudly. Occasionally, this will startle the predator enough that it opens their beak slightly and the Cicada flies away to safety. Birds are not the only consumers of Cicadas. Cicadas, along with crickets, grasshoppers and katydids, are eaten by humans. Not on my Friday night dinner group’s menu!
Cousins to the Cicada are crickets and katydids. These cousins, along with grasshoppers and locust, produce their sounds by rubbing different body parts (legs, abdomen, forewings, etc.) together. Field crickets are found in a variety of places, from fields or lawns to damp areas of buildings. Katydids and grasshoppers live outdoors where they can eat plants. These insects can also be distinguished by how they travel. Cicadas walk or fly, no jumping. Crickets walk or jump but don’t fly. Katydids walk, jump, and some fly. Grasshoppers walk, jump, and fly short distances. Locusts swarm and fly with the wind. Crickets and grasshoppers personally give me the “creeps”, but I always remember reading the Ingalls family in Little House on The Prairie books telling of the locusts attacking the crops. Locusts are over-excited grasshoppers, almost Mr. Hyde to the Dr. Jekyll. What makes little green grasshoppers turn into brown, crop destroying, chomping, swarming locusts? The chemical Serotonin, a compound that sends impulses between nerve cells and affects everything from sleep to aggression in humans. According to a Scientific American article by Katherine Harmon in 2009, “...researchers from universities in the UK and Australia found it took just two to three hours for timid grasshoppers in a lab to morph into the voracious locusts after being injected with serotonin. Conversely, if they gave serotonin blockers, the locust stayed solitary even in swarm induced conditions.” Such are the miracles of science, but I don’t see the sense of a career injecting individual bugs one at a time with chemicals. Grasshoppers, without turning into locust, can destroy plants. Ten adult grasshoppers per square yard are economically damaging to rangeland, according to the USDA. Smaller numbers can damage cropland and gardens, depending on crop type and age. A classic study showed the 6-7 adult grasshoppers per square yard on 10 acres of pasture ate as much as a cow.(1) There are several ways to combat these insects although more than one method might have to be used to be effective.
Diatomaceous earth is a popular garden additive for many different reasons, but most notably because of how it affects pests such as the grasshopper. It is made up pf the shells of fossilized algae. When it comes into contact with an insect like a grasshopper, it dehydrates their body causing them to die. Be careful not to inhale or get it in your eyes. Some say to spray your plants with garlic water to keep those “vampires” away. Verbena, Salvia, and Crepe Myrtle are some of the plants which grasshoppers don’t like. Agricultural producers can help to break the life cycle of grasshoppers by using many of their natural enemies. A fungus, Entomophthora gryllli, can be used against the adult grasshopper in warm and humid areas. A protozoan, Nosema locustae, can be used in baits but often act too slowly. Birds such as quail, turkey or chickens can help control the insect. According to the Agrilife Extension Service (2), one way to control grasshopper populations is to eliminate sites where they deposited their eggs. The insects prefer undisturbed areas, so tilling cropland in mid- to late summer discourages females. However, tilling may reduce soil moisture and contribute to erosion. In Conservation Reserve Program (CRP) acreage, tilling is not an option, but plant tissue can be shredded to reduce the grasshopper food supply. Also eliminate tall grasses, making the areas less attractive to grasshoppers and easier for birds to prey on them.
One of the “fun facts” listed for insects is that grasshoppers predate dinosaurs. Don’t know why they didn’t become extinct, but I would rather listen to the Cicada song of summer than the munching of plants.
(1) https://www.scientificamerican.com
(2) agrilifeextension.tamu.edu