| “ | Old N'Kuru, one of the Galla boys at the post, says it must be the bite of a devil-fly, which makes its victim waste away gradually and die, and then takes hold of his soul and personality if it is still alive itself — flying around with all his likes, dislikes, and consciousness. | „ | |
| ~ HPL: "Winged Death" |
The devil-fly is a fictional type of insect featured in the horror short story "Winged Death", by H. P. Lovecraft and Hazel Heald. These flies are notable for "stealing" the soul or consciousness of those who die after being bitten by them.
Overview[]
Entomologists identify the so-called devil-flies of Uganda as Glossina palpalis, a relative of the common tsetse fly (Glossina marsitans) of South Africa. Science dictates that the devil-fly is dangerous for its habit of feeding off the blood of crocodiles, antelopes, and other animals infected by Trypanosoma gambiense, a parasitic microbe and cause of a potentially fatal disease when transmitted to humans. The first symptoms show up weeks after being bitten, while the illness itself lasts for months and is fatal if not treated.
However, the people who live in and around the jungles inhabited by these insects are also aware of another reason to fear them, as the devil-flies have the supernatural ability to "steal" the consciousness of those they have bitten. The reason for this is unknown, although the phenomenon is believed to be connected to the monolithic ruins of the outposts of the Fishers from Outside and their gods, Tsadogwa and Clulu. Whatever the cause, it has been observed that those who die after being bitten will have their minds transferred to the body of the insect responsible. The only known way to avoid this fate is if the fly perishes before its victim.
In their natural state, devil-flies are "as stupid as they are deadly", as Thomas Slauenwite puts it. They can be captured by the simplest fly-traps and are easy to swat or catch. However, if a person who has been bitten dies while the fly is still alive, the fly will acquire the consciousness of the deceased, including their human intelligence, memories, and personality, thus making them potentially more dangerous.
It's not known whether the curse of the devil-fly is related to the Trypanosoma infection. Slauenwite died from a heart attack before the disease could kill him, but still suffered the same fate as the other victims, finding his mind transferred to the body of the fly after death. On the other hand, it is possible that those who have been successfully treated and survived the disease, such as Mevana, will be able to avoid the curse by simply outliving the flies that bit them, although the fact that the devil-flies live longer than ordinary flies might cast some doubts about this.
Slauenwite's hybrids[]
The devil-fly (Glossina palpalis) is genetically compatible with the Southern African species that Slauenwite refers to as the tsetse fly (Glossina marsitans). When crossbred in captivity, the two species produce fertile hybrid offspring. These hybrids are known to inherit their parents' infectiousness, as well as their ability to acquire the consciousness of the people they kill.
When Slauenwite bred the Ugandan devil-flies with South African tsetses, he observed that the hybrid larvae had a strange appearance that would allow them to be easily mistaken for a new, unrecorded species, even by an expert. About the imago, however, Slauenwite observed that the sheen of the wings was still similar to G. palpalis, while the thorax had "faint suggestions of the stripes of the tsetse", though he also observed "slight variation in individuals". In order to trick Dr. Moore, Slauenwite dyed the wings of his hybrids blue by spraying them with "an isomeric form of ferrous ferrocyanide, with some admixture of potassium salts". (HPL: "Winged Death")
Known victims[]
The following is a list of people known to have been bitten by devil-flies.
Died from the disease:
- Batta
- Henry Moore
Cured:
- Mevana
- Gamba
Died from other causes:
- Thomas Slauenwite
Behind the Mythos[]
In the real world, Glossina palpalis is an actual fly species that is regarded as a type of tsetse, and is indeed known for transmitting the deadly Trypanosoma microbe to humans and other animals.
In "Winged Death", it is odd that Slauenwite breeds the devil-flies for months without making any remark about their strange longevity. The flies that bit Batta and Dr. Moore survived for 3 and 19 months afterwards, respectively, and neither died of old age. In the real world, the lifespan of a tsetse fly is no longer than 4 months. Furthermore, the fact that Dr. Moore took over a year to die from the disease precludes the hypothesis that the extended lifespan might be related to the mind transference, which happens only after the victim's death. However, it is worth noting that, since Slauenwite's flies are hybrids, it is possible that the extended lifespan might be related to the real biological phenomenon known as "hybrid vigour" or heterosis.