Coquerel’s original paper can be found here.
Because I do not read French, I used Google Translate to produce an initial English translation, and then edited that translation for grammar and readability while attempting to preserve the original meaning. This is the version that I used for my studies, and for my review of Coquerel’s conclusions after being given a single adult fly and hearing the gruesome history of how it was obtained. I am posting my rough translation below, such as it is, for anyone else who wishes to review it.
Coquerel, C. (1858).
Note sur des larves appartenant à une espèce nouvelle de diptère (Lucilia hominivorax).
Annales de la Société Entomologique de France, 3(6), 171–176.
Mr. Quoy, the Inspector General of the Naval Health Service, was kind enough to deliver to me a fly that had been sent from Cayenne during the summer by Dr. Chapuis. The larvae of this fly had developed in considerable numbers within the frontal sinuses and nasal cavities of a prisoner, ultimately causing the death of this unfortunate man.
Incidents of this kind appear to be sufficiently common in French Guiana that the chief physician, Mr. Saint-Pair, had observed six similar cases. Three of those patients died after cruel suffering; two completely lost their noses; and the sixth was left with a considerable deformity of the nose.
This condition is all the more serious because its initial symptoms often go unnoticed. At first, the patients may experience only a slight tingling in the nasal cavities, and it is not until alarming complications develop that they seek medical assistance.
In most cases, the symptoms have followed a remarkably consistent course. They may be summarized as follows: tingling in the nasal passages; headache; and, soon afterward, edematous swelling of the nasal region, spreading to a greater or lesser extent across the face. This is followed by profuse nosebleeds and extremely severe pain, which patients compare to blows inflicted with an iron bar. The larvae produce numerous ulcerations within the nose. General symptoms indicate a severe inflammatory reaction, and death may result from meningitis or from erysipelas of the scalp and face. In patients who survive, there may be more or less extensive destruction of the nose.
In one case reported by Mr. Saint-Pair, more than three hundred larvae had already been removed by means of injections, but it proved impossible to expel them all. They were soon observed reaching the eyeball and crawling between the eyelids. The lower eyelid became gangrenous and fell away as a flap, leaving the lower margin of the orbit exposed. The worms invaded the mouth, eroded the gums, and exposed the upper jaw. The patient died seventeen days after his admission to the hospital.
Unfortunately, medical science is almost powerless to halt these terrible ravages. Injections penetrate only with difficulty into the recesses of the sinuses, especially when the irritated mucous membrane has become swollen and inflamed. Even when the larvae are killed with irritating liquids or mercurial solutions, their bodies remain as foreign material. They putrefy within the frontal cavities and become the source of further complications. Trepanation of the sinuses may, perhaps, be the best treatment that could be employed.
The prisoners transported to the Cayenne penal settlements were warned of the dangers associated with the entry of insects into the nasal cavities and were instructed to report to the hospital immediately if they suspected that such an accident had occurred. A few days later, one of the transported prisoners felt a fly enter his nose. He immediately inserted his hand and removed or crushed it. According to Mr. Saint-Pair’s description of this insect, it appears evident to me that it belonged to the species described here. At the same time, attempts were made to rear the larvae through their metamorphosis. Several were placed upon meat in a stoneware vessel covered with a screen, but all died before reaching the pupal stage.
Finally, after several unsuccessful attempts, Mr. Chapuis succeeded in obtaining a perfectly emerged [from the puparium] adult insect. This fact is of the greatest importance, for it was the first time that an adult had been obtained from a larva maintained under these particular conditions. The following is a description of this dipterous insect, which appears to constitute a new species.
LUCILIA HOMINIVORAX, Coquerel
Plate 2, Figure II
Length: 9 millimeters.
Antennae tawny; the base of the first and second segments, and the tip and upper border of the third segment, brownish; arista brownish. The third antennal segment has grayish reflections. Proboscis dark brown; palpi testaceous. Face and cheeks bright yellow, covered with tawny down; several black bristles present at the epistome, which lacks any notable projection. Forehead broad, with two rows of black bristles on a yellowish ground and a median reddish-brown band with brownish reflections. Vertex brownish, with blackish reflections. Thorax very glossy dark blue, with whitish-gray reflections along the sides and anterior margin. Three broad longitudinal bands with black reflections are bordered by an intense blue that changes to purple. A dark-blue band extends from the shoulder to the insertion of the wing and displays purplish reflections.* Shoulders bluish green. Scutellum purplish blue, with green reflections. Abdomen bright blue, with whitish-gray reflections and scattered black bristles. The area beneath the scutellum is black. A median dorsal line has black reflections. The posterior margins of the segments are dark blue, changing to violet-purple. The tip of the fifth segment is of the same color. Halteres pale testaceous. Calypters almost white; the lower margins pale whitish and the upper margins brownish. Legs black, with a dark-brown sheen. Wings grayish along the outer margin and blackish at the extreme base. The outer longitudinal vein forms a sharp angle and is strongly concave beyond it. The second transverse vein is sinuous.
This species is closely related to Lucilia incisuralis Macquart (Diptères exotiques, vol. II, part 3, p. 147), reported from Brazil. The wing veins have approximately the same arrangement. Our species, however, is easily distinguished from that species by its coloration and especially by the size of its head, the posterior portion of which is broader than the corresponding portion of the prothorax.
It also appears to bear a strong resemblance to Lucilia fasciata Walker (Insecta Saundersiana, p. 337), from Brazil. It differs, however, if one may rely upon the published description, in the coloration of the legs and antennae, as well as in the coloration of the margins of the calypters.
Seeing the larvae of this dipterous insect develop in such numbers within the human body, while dying after they were removed from the frontal sinuses and placed upon meat, one might be inclined to regard it as a newly discovered parasite specific to the human species. To adopt this view, however, would lead us into serious error.
Mr. Moquin-Tandon, professor of natural history at the Faculty of Medicine in Paris, has rightly observed that the essential feature of parasitism is the remarkable fact that a parasite lives at the expense of the animal it inhabits but, except under very unusual circumstances, does not cause that animal’s death. This must necessarily be so; otherwise, either the parasite or the animal that sustains it would eventually disappear. Such a result would be contrary to the general tendency of nature, which, although showing little concern for the individual, nevertheless provides [the parasitizing] species with the conditions necessary for their continuation.
The destruction caused by the Cayenne flies must therefore be regarded as an unusual and accidental occurrence. It is probable that the eggs were deposited at the entrance to the nasal cavities of individuals who paid little attention to cleanliness and who may have been overcome by deep sleep or intoxication.
When the blow fly, Calliphora vomitoria, deceived by the cadaverous odor of Arum dracunculus, entrusts its eggs to that plant, it commits an error of an even more remarkable kind.
Similar incidents have also been observed in our own climates. Unfortunately, the accounts recorded by authors unfamiliar with entomology are entirely lacking in precision, making it impossible to determine which species of dipterous insect was involved.
* In 19th century French entomological writing, “épaule” (“shoulder”) is the informal term for what anatomists called the humerus or calus huméral – the small rounded projection at the front corner of the thorax, on either side of the mesonotum (the dorsal plate of the middle thoracic segment). In modern English, this structure is called the humeral callus (plural: humeral calli). Sometimes it is called the humeral angle or simply the humerus. It sits at the anterolateral corner of the scutum (dorsal mesonotum), just above and behind the base of the neck, and anterior to the wing base and the notopleuron.