Cicada Killer Larvae: Trials & Tribulations of Tiny Wasps

In this blog, we discuss the various ordeals and gauntlets that cicada killer larvae have to contend with so that they can turn into adult wasps. Have a read!

From the time female cicada killers mate to the phase when the pupae finally emerge as young cicada killers, there is a lot that goes on in the life of these wasps.

Cicada killers (Sphecius speciosus) spend only 1/5th of their lives as the wasps that we see around us. The rest of the time is spent underground, in burrows.

In this article, we look at the cicada killer larvae, their birth, feeding habits, predators that prey on them, and more.

How Cicada Killers Lay Their Eggs

When adult cicada killers come out of their burrows, it is already summer.

We are talking late June to early July when the sun is out and the world is lush and teeming with life again.

These adults don’t live very long, however, just 2-2.5 months. It just seems that long because they are buzzing all over the place.

By mid-September, most of them have already gone to their heavenly abode.

The females live longer than the males because they need to do more than just mate – they are responsible for ensuring the survival of the species.

The poor males are born simply to mate and die immediately after.

You can see them flying around gardens and yards, looking for places where they can dig holes in the ground.

Most often, these solitary wasps make their nests near the edge of a crossway or a pavement or else in berms, patios, and driveways.

The nests are most often about 6 to 10 inches deep, and the opening of the hole is quite wide – about ½ inch. It is easy to find cicada killer nests by the mound of loose soil near them.

Provisioning The Cells

Once they are done with their nests, their next port of action is to hunt down cicadas. They find their prey and sting them, causing instant paralysis.

When the cicada is immobilized, the wasp then holds it upside down between her legs and carries it back to her nest.

Often, the cicadas they carry home are more than twice their weight, but the wasp persists and brings many more bugs in the same way.

Back home, the Mumma wasp carries it into one of the cells of her nest, lays her egg (only one per cicada), and then closes the nest cell’s mouth.

Interestingly, the mother knows which of her eggs are going to become female and which ones are male (their gender reveal parties must be rather boring).

She uses this information to provide more than one cicada for the girls, while the boys get just one each.

The reason behind this discrimination is simple – the female wasps are bigger, need to bear eggs, and live longer.

Coming back to our story, there are several of these cells in each nest (can be upto ten or even more). Each cell is meant for one and only one egg (but maybe more than one prey, as just discussed).

Eggs Hatch and the Larvae Come Out

It takes a day or two for the eggs to start hatching, but when they finally do, the larvae have a huge supply of food already available to them.

Within the next two weeks, the larvae first suck out the blood and juices of the cicada and then eat the other organs one by one, leaving the neural ganglia (the insect equivalent of a brain) and heart for the end.

They may be small, but these grub-like larvae sure like their meat fresh.

Pupation, Overwintering, and Adult Wasps

After the larvae finish their lavish meal and are ready for the next stage in about two weeks’ time, they create a cocoon for themselves coated with mud.

They then go to sleep and let the seasons change around them. During winters, these bugs remain hidden in their cocoon, awaiting warmer weather outside.

After winter is over, the larvae come out of their cocoons to pupate. Pupation is rather unremarkable and takes about a month’s time.

Finally, the adult wasps are ready to come out and repeat the life cycle again.

Velvet Ants Parasitize the Parasitoids

What we just described above was the best-case scenario for these larvae. However, as the old adage goes, there’s many a slip ‘twixt the cup and the lip.

The larval stage is the most vulnerable point for these cicada killers. Unfortunately, there are others who look at the wasps and say – hey, we can do this parasite thing too!

Turning the story on its head, the rather unfortunately named velvet ant (which is actually a wasp, not an ant) digs up the closed nest chambers.

She then places her own eggs on the larvae of the cicada killer wasp to do exactly what the larvae themselves are doing – parasitize its host.

This cruel twist of nature is not unique to cicada killers, however.

The bright orange-colored velvet ant does this to honeybees and other ground wasps as well. That said, cicada killer larvae are still one of their favorite grubs.

Satellite Flies Steal Their Prey in Midair

As if it wasn’t bad enough that other wasps are parasitizing their larvae, there are creatures that also parasitize the cicadas themselves.

Satellite flies are a species of parasitic flies that love to hover around just over or near the wasps that they parasitize.

These flies produce live maggots instead of laying eggs. But their maggots are just as hungry as the cicada killer larvae.

When the female cicada killer subdues her prey and is carrying it home, these flies will carpet bomb it with their own maggots, often just before she enters her burrow.

The flies are very precise with their target, and their maggots end up inside the cicadas, eating them up by the time the poor cicada killer larvae even have a chance to hatch.

Theif Cicada Killers

One final twist in the tale is that sometimes, there are thief cicada killers who just wait around for other females to provision their nest.

They then go in and lay their own eggs on the cicada to get all the nutrition and benefits that were meant for the other wasp’s eggs.

This behavior is called kleptoparasitism, and it is quite a common trait in cicada killers.

In fact, scientists have even observed some cicada killer wasps chucking out these thieves from their nests.

It makes sense that evolutionarily cicada killers have taken to thieving from other wasps of their own species.

Life is not very easy for these insects. For one thing, not all female wasps grow to be strong and powerful; a lot depends on how much food their mothers were able to provide before they were born.

On the other hand, hunting cicadas and then carrying them back to the nest is hard work. Cicadas can be quite heavy, almost twice the size of poor wasps.

Therefore, many of the smaller wasps in the family have created this easy way out to simply sit back, relax and let others do all the work for them.

Kingbirds Steal Their Cicadas

One last ordeal that the female wasp must run in order to provision her nest for her children is to contend with Cassin’s kingbirds and thick-billed kingbirds.

These birds fly in the air and wait for cicada killers to fly their prey back to their nests.

The female wasp is extremely vulnerable at this time because her prey may be twice as heavy as she himself is.

Moreover, after having battled and subdued her prey a few instants ago, she is probably already tired.

At her weakest, kingbirds swoop in and steal her hard-fought cicadas from her and carry them away in their beaks, leaving behind the wasp to rue her loss and start back again.

These birds use the perch atop mesquite and agave trees to keep an eye on their prey.

It makes a lot of sense for kingbirds to do this. After all, finding cicadas is quite hard because they are able to camouflage themselves quite well in thick foliage among plants

So instead of searching for their prey, they let the female cicada killer wasps do all the work, and once the paralyzed cicadas are primed for eating, they simply swoop in and steal the poor larvae’s meal.

Wrap Up

We hope you had fun reading about the trials and tribulations of cicada killers and the immense difficulties with which their larvae are able to survive in a cruel world full of parasites and thieves.

Unfortunately, apart from these other bugs, cicada killers have one more enemy – a threat larger than any of these. And that enemy, as you might have guessed, is us humans.

We often end up mistaking these gentle giants of the wasp world for more dangerous varieties such as yellow jackets or Asian giant hornets.

They are nowhere as aggressive or harmful as either of these species. But despite that, large swathes of these wasps are wiped out by humans every year with wasp sprays and other insecticides.

After reading this blog, it should be obvious that these poor creatures are struggling to survive in a big bad world and don’t need to contend with another apex predator like ourselves.

Thank you for reading.