dshubble's picture

Fly-killing fungus

Observed: 20th May 2010 By: dshubble
Leaf Beetle Recording SchemeSouthampton Natural History Society
dshubble’s reputation in Fungi and Lichensdshubble’s reputation in Fungi and Lichens

A fungal pathogen which kills flies at the top of grass stems, from where spores can be released. Fungal structures can be seen exiting the fly's abdomen.


Caution: Do NOT use iSpot to identify fungi to eat!

Some fungi are very poisonous so a mistaken ID could have serious consequences.

    Likely ID
    Entomophthora scatophaga
    Confidence: It's likely to be this, but I can't be certain.
Species interactions

No interactions present.


Dioctria's picture

Nice examples

Nice examples. For those interested in seeing more fascinating insect-killing fungi there is a group on Flickr for examples from anywhere in the world.


dshubble's picture

Fly fungus

Thanks - I was pleased to squeeze a decent shot or two out of my compact :)

I've seen quite a few of these on hoverflies, but I don't recall ever having found them on this fly before.

dshubble's picture

Fly fungus

For those interested, I've been in touch with the county fungus recorder and sent off samples - apparently, this is one of two fungal species, either E. muscae which is rare on this fly species, or E. scatophaga which is rarer still. I'll post the result if/when it is determined...


anonymous spotter's picture

Insect-killing fungi

What is fascinating is how they influence the infected animal's behaviour to maximise the dispersion of spores.
I read of research relating to the cat version of toxicara (a disease we can catch from dogs). Infected mice lost their fear of the smell of cat urine.
So maybe we're being manipulated by our pets in ways we never imagined?

dshubble's picture

Influence on behaviour

The flies typically die in elevated positions (e.g. high up grass stems), with the proboscis extended and attached to the substrate, the legs spread, the abdomen angled away from the substrate and the wings raised above the thorax; all these factors pronote spore dispersal. It is also possible that the fungus uses a biological clock to increase the chance that flies are killed at a suitable (to the fungus) time of day - as I understand it, afternoon to evening (more breezy conditions, benefit of warmth during the day?). The behavioural change occurs by hyphae penetrating the fly's brain, though I don't know if the detailed mechanism is well understood e.g. how the fungus 'codes' for the fly to go up, spread its appendages etc.

Males are also more highly attracted to dead female flies infected with the fungus; this may be because males orient to the larger abdomen and/or chemical cues (pheromone inducement or mimicry?).


Norwichnaturalist's picture

Entomorpha muscai

This is probably E. muscai but would be interested in the resulting determination

Colin Jacobs.
Wild Flower Society member

dshubble's picture


Despite my ID above, I agree E. muscae is more likely - I think the samples are being sent to Kew where there are experts who know about such things...


Tony Rebelo's picture

entomopathogenic fungi

No interaction to the Fly?

Thanks for this : helps with our observations in ZA: http://www.ispot.org.za/node/245837