Do you remember this quote “Not all men are kings, but all kings are men”? Well, entomologists say: “Not all wasps are hornets, but all hornets are wasps.”
The large black and yellow cicada killer is not a hornet although this insect is large enough to fool you into thinking it could be the invasive Asian Giant Hornet. The cicada killer is a harmless wasp, a solitary, burrowing, docile, gentle giant.
They have been compared to a toothless dog: “all bark and no bite.” The male has no stinger but is very territorial and will defend his area with his loud buzz, flying directly at people, dogs or anything else he perceives as danger. Both male and female are harmless to us, but not to the cicada because for the cicada this wasp is deadly.
They are incredible hunters and clever flying machines as well as effective embalmers who turn cicadas into zombies. After being injected with venom from the female wasp the immobilized cicada is powerless to do anything other than breathe, and he is helpless to stop the wasp from sealing him in an underground tomb with one of her eggs which will hatch into a very hungry larva. The female wasp injects the live cicada with paralyzing venom that will keep him immobile for the rest of his life. A cicada injected with venom actually lives longer than a cicada that has avoided the killer wasp.
Unlike most mothers, this wasp can determine the sex of her offspring. If she leaves only one cicada for one egg a male wasp will develop. Because females are nearly twice the size of males it takes the nourishment of two cicadas for a female to develop properly. Thus the female wasp will leave two cicadas for an egg if she wants a female wasp to develop.
Cicada killers carefully select their nesting sites. They look for a southeast facing slope with large deciduous trees nearby. They do not nest in hydric soils. She prefers light-textured, well-drained soil to build her U-shaped mound and burrows.
These hunter wasps that dig burrows have front legs that are equipped with rake-like structures. She moves the dirt out then pushes it away from the hole using her abdomen like a broom.
One female wasp can fill a dozen or more nests during her life, thus clearing our world of more than 30 cicadas a season, and she shares her burrow with other females that also are building nests. As they go about their work, the females are constantly visiting and pollinating flowering plants, and this is why the colorful black and yellow wasp needs to be left alone.
These wasps do not live in colonies where they would sting to defend their nests. They are solitary and sharing tunnels makes it easier to spot them as they buzz in and out of their tunnel entrances.
Another action you may notice is the wasp flying back and forth from the burrow to edge of the woods. This is her technique for memorizing the location of her burrow and how to return to it.
The cicada lives only a few weeks above ground if he is lucky. He emerges from below ground where he has been living on tree roots for one or more years. When he emerges from his underground nest he breaks out of his larval case and leaves it clinging to a tree trunk or on other vegetation.
Looking like a ghost of his future self the young cicada climbs upward toward the warmth of the sun. Before his skeletal form hardens and turns dark he cannot fly and must take frequent rests. At this point the young cicada is vulnerable.
If he survives this stage the cicada gets its color and strength then begins to seek a mate. A male sings a loud, piercing song and in return a female produces loud clicks. Following the cicada cacophony of singing and clicking, male finds female. Meanwhile the wasp is also listening to the singing and clicking and comes in for the attack. Finding a cicada the female wasp paralyzes it using her powerful stinger then clutching it to her abdomen with her two strong middle legs the wasp hauls the cicada to her tunnel. The cicada can be nearly as heavy as the wasp. So, if it is too heavy for flight from ground level, the wasp, still clutching her prey, climbs up a tree then will fly in a direct route down to the tunnel and nest she has already prepared. Once safely inside the tunnel she leaves one of her eggs on the immobilized cicada and seals both in their tomb, then moves on to prepare the next nest.
Within days the egg becomes a wasp grub and enters the body of the zombie-like cicada then begins to eat. After having eaten all there is the grub overwinters in place next to the cicada’s empty shell.
According to Google, the word “cicada” is a runner up for its “Word of the Year 2021.” The word was heavily researched due to the occurrence of the 17 year cicada in the northeast.
Many people changed their vacation plans due to the incredible cicada cacophony near some vacation spots.
There was also fear of the Asian Giant Hornet (Vespa mandarinia), but that hornet has not come to Louisiana, or even east of the Rocky Mountains. It has only been found in the Pacific Northwest of North America, but the hornet closely resembles the large cicada killer, which can be found in any forest or garden in Louisiana.
It is important to learn the difference between the dangerous, the harmless and the helpful denizens of the insect world.
Few insects are dangerous to humans. They are fun to watch, they are harmless, helpful and, most of all, essential to our ecosystem. Give these wasps the right-of-way and let them entertain you. You might want to add them to your watch list along with the birds, bees and the butterflies. P
(Betsy Trammell, Louisiana tree farm forest landowner and CenLa Master Naturalist.)