Praying Mantis Parasites: They Control the Insect Like Zombie

What’s the worst thing that can happen to a praying mantis? It’s not being eaten by its mate, though this only happens to the male. The answer is being parasitized. They go about their daily routines, sleeping and eating as usual, until one day, they die without understanding why and how it happened. Here are four commonly found in praying mantis parasites.

Horsehair parasite praying mantis

Zombie praying mantis parasites

One of the most horrible praying mantis parasites is the hairworm. It takes control of praying mantises and makes them jump into water.

Hairworms (Chordodes sp.), including a specific species known as Chordodes fukuii, begin their life in aquatic environments. Here, their larvae will try to be eaten by aquatic insects like tadpoles or mosquito larvae.

Praying mantis parasites worm
Hairworm in praying mantis is a great example for the survival strategies of parasites

Once inside these new hosts, the hairworms mature by consuming nutrients and then compel their host to commit suicide by drowning. The hairworms then are extracted from the praying mantises. They breed and lay eggs, starting a new lifecycle.

According to Current Biology, the worms take control of their host by imitating the host’s brain chemicals, which are important for sending messages throughout the body. This mimicry triggers big changes in the worm’s genes, turning on almost 3,200 genes and turning off about 1,700. This gene activity allows the worms to make proteins that can change the host’s behavior without changing the host’s own genetic code too much.

What’s interesting is that the worms can do this by stealing copies of mantis DNA via a process called horizontal gene transfer. Unlike the usual way genes are passed down from parents to their offspring, in horizontal gene transfer, the worms directly grab DNA from their host. This explains why the parasite has over 1,400 genes that are very similar to those of their host. This borrowed genetic material gives the worms the ability to manipulate their hosts effectively.

Parasite transmission from insect prey to praying mantis
The praying mantis gets parasites by eating infected insects

To get the mantises to go into the water, the parasites turn on certain genes that make the praying mantis attracted to light. They also make their hosts more active around noon, when it’s easy to spotlight reflecting off surfaces like water. The more they move around, the higher the chance they will stumble upon water and drown.

It was once believed that the mantis and other creatures infected by hairworms were drawn to water by the bright light reflecting off it. However, this theory doesn’t explain why hairworms don’t lead their hosts into shallow, brightly lit waters, like puddles.

Research published in Current Biology has shown that the real draw is the way light reflects off water, known as polarization. Polarized light moves in a single direction. Water reflects this light in a mostly horizontal direction, and insects can detect this kind of light.

How to tell if a praying mantis has a parasite?

To know whether a hairworm is in your praying mantis or not, you can check these symptoms below:

  • Color changes: If a mantis has parasites, its color might turn dull or less bright. Its patterns may not look as vivid, and the color could even change slightly.
  • Grooming changes: Mantises with parasites might start grooming too much, always trying to clean themselves. However, some might stop grooming and end up looking unkempt.
  • Praying mantis with parasites become weaker and lose their appetite, showing less interest in food or not wanting to eat at all.
  • The infected mantises become very sluggish and inactive. They might stay still for a long time or lie down.
  • Abnormalities on the body like strange bumps, enlargements, or shape changes in its legs and belly.
  • Behavioral manipulation: The praying mantis will develop water-seeking behavior. It can feel really thirsty and try to look for water more than usual.

Praying mantis worm parasite extraction

You can try to extract the hairworm parasite from the praying mantis by immersing the insect’s abdomen in water. This method triggers the fully developed horsehair worms inside to instinctively come out of the mantis’s body through the anus. However, the praying mantis may die shortly after parasite removal. The horsehair worm feeds on the mantis’s body mass, leading to the insect’s eventual death.


Tachinid mantis parasitoids, such as Masiphya, are familiar praying mantis parasites. Masiphya is a small fly that preys on mantis, particularly the Carolina mantis.

Here’s how it works: The female fly lays an egg inside the mantis, close to its front legs. The egg hatches into a larva, which moves through the mantis’s body and eventually settles in its abdomen. The larva feeds on the mantis’s blood and then emerges from the body to pupate in the soil.

Mantises that have been parasitized often lack wings and are only about half the size of healthy adults. The flies take out a lot of the mantises’ blood, preventing them from fully growing into adults, but they still manage to survive the experience.


The next praying mantis parasite is wasps. There are 2 types of wasps that parasitize on the praying mantis: Torymid wasp Podagrion and Scelionid wasp Mantidophaga. While the first one only parasitizes mantis egg cases, the second one parasitizes both ootheca and adult mantis.

The Mantidophaga is a small type of wasp that targets praying mantises throughout its life. This wasp chooses a living adult mantis to land on. It settles on the mantis’s wings and feeds on its blood. It doesn’t matter if the mantis is male or female; the wasp can switch hosts during mating if needed, with up to five adults congregating on a single mantis.

praying mantis egg case - ootheca
Praying mantis eggs also get parasites

When female mantises lay their eggs, the wasp seizes the opportunity to deposit its own eggs inside the egg case, or ootheca. These wasp larvae then voraciously consume the mantis eggs until they reach maturity, at which point they transform into pupae. Once the wasp emerges from its larval stage, it seeks out a new mantis to parasitize.


The last praying mantis parasite is fungus, Beauveria to be more specific. When Beauveria infects an insect, it kills it and then grows on its body. Unlike some other fungi, Beauveria doesn’t control the insect’s mind or behavior. Instead, the insect just holds onto whatever it was on when it died. Insects infected with Beauveria end up looking white.




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