Cicada Killers More Frightening than Dangerous


The insect is big.  The body can be two inches long, and the extended wingspan three to four inches long.  It can be terrifying as it zips around the yard, dipping this way and that looking for its prey, looking for all the world like a giant, angry hornet.

The insect is large, but fortunately, not angry.

Frightening Appearance

The insect is the Eastern cicada killer (Sphecius speciosus) and it is really not interested in anything other than cicadas, no matter how frightening it looks.  In fact, although the female does have a stinger, the cicada killer is not aggressive.  The wasp’s venom is reportedly somewhat painful.  However, the female will usually ignore humans and other animals unless she is stepped on or handled roughly.  The venom’s use is to subdue cicadas.

Males Are Harmless

Male cicada killers are very aggressive, but since they do not possess a stinger, their aggression amounts to dive bombing an intruder.  The males also seem to have very poor eyesight.  Add their need for corrective lenses with their aggressiveness, and the result is a very belligerent, pesky but ultimately harmless drone.  Males have a sharp spine on the abdomen and may try to jab with the tip, but it is a useless gesture.

Laying Eggs on Cicadas

Female cicada killers burrow holes into soil.  The burrow may be up to 10 inches deep.  After she digs a hole, the female will begin to hunt for cicadas.  Once she finds one, she stings it and then carries it to her burrow.  She drags the cicada into the hole and lays an egg on it.  The living, but paralyzed cicada will provide food for the newly hatched larva.  To see cicada killers in action, go to this link, https://vimeo.com/19974518.

Well-Drained Soil

Cicada killers drill burrows in sandy, well-drained soil exposed to sunlight.  Their preference is to dig the burrows along the edges of sidewalks, along driveways and along the sides of ditches.  The insect’s burrow can be recognized by a U-shaped mound of very fine soil around the ½-inch burrow.  Although they can infest a lawn, they prefer to build their nests in locations where there is little or no vegetation.

Life Cycle

The female will lay male eggs on single cicadas.  Since the female is significantly larger than the male, female eggs are usually given two or three cicadas to consume during their larval stages.  Eggs will hatch in two or three days.  The larvae will feed on the cicada for a week or more, spin a cocoon and overwinter in the burrow.

Once emerged, the females will mate, spend several weeks creating burrows and eating (mostly flower nectar) until they begin hunting for cicadas.  Cicada killers only have one generation per year.

Hunting Cicadas

A female cicada killer is relentless in her search for cicadas.  Once she has found one, she stings it, taking it back to the burrow.

Control

Unless the population of cicada killers is immense and bothersome, it may be a wise option to simply ignore them.  In addition, as is often the case with insects, there are generally fewer cicada killers around than cicadas.  Nature tends to seek a balance.

Although there are insecticides that work, cheap tennis or badminton rackets also work really well.  Use insecticides with discretion and sparingly, if at all.  Spraying into burrows also contaminates the soil, and kills beneficial insects.  Whatever is used, it is difficult to eliminate a population of cicada killers.  Applying the old tenet of “live and let live” could be a potential (and really the best) solution.

For more information about gardening-related topics, contact the Montgomery County Master Gardeners hotline at 936-539-7824 from 8 AM to noon and 1 PM to 5 PM Monday through Friday, or visit the Texas A&M AgriLife Extension office at 9020 Airport Rd, Conroe, TX 77303.  Visit the Master Gardener website for upcoming programs and plant sales at http://www.mcmga.com/.