Dear Mattia,

I'm not at all a specialist on horsehair worms but I never read anything on predation on horsehair worms. This is probably mainly because of their more or less "hidden" lifestyle and their slow movements and hard stick-like appearance (or at least they do not really look like a meal for predatory animals, but more like organic debris). They will however been eaten more or less by chance by fish (when in the water) or by predation on their host in which they live. The two examples you refer to fall into the latter category. I do not think you can consider this as predation of Mantoida. In these cases the mantis had the intention to catch an insect (in this case a cricket) and during the consumption of it's prey it considers everything within the cricket as part of it's meal. In other words: the mantis is not aware of the horsehair worm and as far he is concerned he is just eating a cricket, because the eating of the horsehair worm is not intentionally you cannot consider this as predation on horsehair worms.

I wish you success in your research on horsehair worms, it is a very interesting subject!

All the best,

Kevin

Dear Kevin,

I agree with you about the accidental predation.

About fish; there are still doubts about the fact they eat horsehair worms, while crickets infected by worms are eaten by fishes (see the researches made by Sato and his equipe in Japan). There is a report in Italy about Austropotamobius pallipes (the white-clawed crayfish) eating adults worms, but the species of nematomorfa weren't identified.

Thanks for the interest about the topic and the answer!

Greetings,

Mattia.

I agree with Kevin

mantis usually choose the nearest preys

Dear Mattia,

I saw the video several times and I got the impression, the mantis does not eat the worm but the body of the other mantis.

The (parts of) worms lying on the ground fit to this conclusion.

The picture you shared looks really as if the mantis feeds on the worm.