#1139 & #1140 - Parasitic Fungi
#1139 - Akanthomyces sp. - Entomopathogenic Fungus
Jolita Burneikis found this on a Kurrajong at Captain Creek, Queensland. Not surprisingly, she was a bit baffled as to what it might be, since it wasn’t entirely clear if it was animal or vegetable.
It’s neither - it’s a large hawk moth that’s fallen victim to a parasitoid fungus.
Akanthomyces is an anamorph of Cordyceps - a form taken by that notorious organism when it has parasitised hawk moths, spiders, and certain other hosts. If it has sprouted from another host - or even from a caterpillar - the fungus might look completely different, and be described as a different species. Genetic studies have also split off some the Cordycipitaceae into a new family, the Ophiocordicipitaceae.
That confusion aside, there’s some 400 species of Cordyceps and related fungi, mostly in tropical areas. The majority infect invertebrates, but a few infect other fungi. Some are infamous for their ability to control the host. The Ophiocordyceps unilateralis species complex, for example, infects ants who will climb up and clamp their jaws to the underside mid-vein of a leaf, and promptly die. The the fungus will sprout from the neck of the ant, at just the right height and humidity to spread the spores over any other ants that might be crawling around below. It seems as though the ascospores hatch as soon as they find themselves in a host’s throat, punch out through the pharynx walls and into the brain, and start taking over its behaviour.
In the case of the moth in the photos, the unfortunate moth settled into a resting position, got a good grip, and died. The fungus promptly consumed the wings and all internal tissue, and sprouted from every chink in her exoskeleton.
I’ve found another Cordyceps, years ago - a vegetable caterpillar. These burrowing caterpillars sprout a long club-like growth from their heads after infection. I’m not sure how the fungus manages to infect a caterpillar that spends its life underground - perhaps the spores infect the caterpillars after they hatch, and before they burrow, and the infection stays with the caterpillar in the months or years until it’s ready to pupate, and only then takes control.
#1140 - Entomophthora muscae - Fly Destroyer
Last November I was getting out of my van, glanced down, and saw something odd clinging to the underside of a rusted metal bar at ankle height. It was a housefly, apparently stuck to the metal by its mouthparts.
If you noticed that my last few days of posts have all been about Cordyceps, you might guess that this was the result of a parasitic fungus, and you’d be right.
Entomophthora muscae (formerly Empusa) is an obligate pathogen of flies, in a good range of families. It’s difficult to keep viable in the lab, and colonies can only be maintained by infecting fresh flies. Victims survive 5 days to a week as the fungal hyphae invade every organ. Then they are forced to land, and to start crawling upwards, and attach themselves to a surface with sticky saliva, spread out their wings and legs, and promptly die. After that, the fungus erupt from every joint in the abdomen - the white fuzz in the photo - and the spores are fired out into the surrounding countryside. The wings and legs are held out the way for just that reason.
If the spore lands on another fly, good for the fungus, but it has a another trick up its sleeve - if it doesn’t find a host immediately, the spores wait a few days and sprout into a simple tower, grow more spores at the end, and have a second chance at infecting a host. According to some sources, sometimes these secondary spores manage a third go, before any food reserves are exhausted.
Funnily enough, the Fly Destroyer is quite vulnerable to high temperatures, so I wasn’t expecting to see it in an Australian summer, as happened with here. In fact, infected flies can cure themselves of the infection by resting in hot areas.
Coolup, Perth
Jolita Burneikis found this on a Kurrajong at Captain Creek, Queensland. Not surprisingly, she was a bit baffled as to what it might be, since it wasn’t entirely clear if it was animal or vegetable.
It’s neither - it’s a large hawk moth that’s fallen victim to a parasitoid fungus.
Akanthomyces is an anamorph of Cordyceps - a form taken by that notorious organism when it has parasitised hawk moths, spiders, and certain other hosts. If it has sprouted from another host - or even from a caterpillar - the fungus might look completely different, and be described as a different species. Genetic studies have also split off some the Cordycipitaceae into a new family, the Ophiocordicipitaceae.
That confusion aside, there’s some 400 species of Cordyceps and related fungi, mostly in tropical areas. The majority infect invertebrates, but a few infect other fungi. Some are infamous for their ability to control the host. The Ophiocordyceps unilateralis species complex, for example, infects ants who will climb up and clamp their jaws to the underside mid-vein of a leaf, and promptly die. The the fungus will sprout from the neck of the ant, at just the right height and humidity to spread the spores over any other ants that might be crawling around below. It seems as though the ascospores hatch as soon as they find themselves in a host’s throat, punch out through the pharynx walls and into the brain, and start taking over its behaviour.
In the case of the moth in the photos, the unfortunate moth settled into a resting position, got a good grip, and died. The fungus promptly consumed the wings and all internal tissue, and sprouted from every chink in her exoskeleton.
I’ve found another Cordyceps, years ago - a vegetable caterpillar. These burrowing caterpillars sprout a long club-like growth from their heads after infection. I’m not sure how the fungus manages to infect a caterpillar that spends its life underground - perhaps the spores infect the caterpillars after they hatch, and before they burrow, and the infection stays with the caterpillar in the months or years until it’s ready to pupate, and only then takes control.
#1140 - Entomophthora muscae - Fly Destroyer
Last November I was getting out of my van, glanced down, and saw something odd clinging to the underside of a rusted metal bar at ankle height. It was a housefly, apparently stuck to the metal by its mouthparts.
If you noticed that my last few days of posts have all been about Cordyceps, you might guess that this was the result of a parasitic fungus, and you’d be right.
Entomophthora muscae (formerly Empusa) is an obligate pathogen of flies, in a good range of families. It’s difficult to keep viable in the lab, and colonies can only be maintained by infecting fresh flies. Victims survive 5 days to a week as the fungal hyphae invade every organ. Then they are forced to land, and to start crawling upwards, and attach themselves to a surface with sticky saliva, spread out their wings and legs, and promptly die. After that, the fungus erupt from every joint in the abdomen - the white fuzz in the photo - and the spores are fired out into the surrounding countryside. The wings and legs are held out the way for just that reason.
If the spore lands on another fly, good for the fungus, but it has a another trick up its sleeve - if it doesn’t find a host immediately, the spores wait a few days and sprout into a simple tower, grow more spores at the end, and have a second chance at infecting a host. According to some sources, sometimes these secondary spores manage a third go, before any food reserves are exhausted.
Funnily enough, the Fly Destroyer is quite vulnerable to high temperatures, so I wasn’t expecting to see it in an Australian summer, as happened with here. In fact, infected flies can cure themselves of the infection by resting in hot areas.
Coolup, Perth