AT THE SIGN OF THE DEATHSHEAD

19th-Century colour engraving of the deathshead hawk moth


"On the 4th of September [1883] one of these insects flew into a house near the Brunswick Brewery, Leeds. There was a sick child in the house at the time, and the mother, terrified at what she thought an evil omen, could not be pacified for some time. The insect was secured and taken to Wardman's, the bird-stuffer's."

John Grassham - The Naturalist's World (January 1884)


Acherontia atropos, the insect referred to above, is nothing if not distinctive in appearance. A rare migrant to the UK, with a wingspan that can exceed 5.5 in and a weight that can fall little short of 0.1 oz, it is incontestably Britain's largest species of moth. Its plum-coloured, wavy-lined forewings and rich golden-yellow hindwings, not to mention its bulky body striped boldly underneath in dark brown and primrose bands, also render it one of this country's most attractive moths. Nevertheless, all of these features are eclipsed by a single, but very singular, additional characteristic - one which instantly identities this species and distinguishes it from all others in Britain, which has woven around it a near-indestructible web of folklore and fear, and which has earned it its extremely sinister-sounding English name.

Pinned specimen of the deathshead hawk moth (Ivo Antušek/www.biolib.cz)

This feature is a strange marking on top of its thorax's front portion, which, by a grotesque quirk of nature, forms a surprisingly realistic image of a human skull, ghostly white in colour with black, empty eyesockets. Enhancing this macabre image, the thoracic hairs bearing it are erectile, so that when they are raised up and down while the moth is resting, the 'skull' appears to be nodding!

To many superstition-ridden people in the past (and even to some today) this bizarre insignia is considered to be nothing less than the symbol of Death itself, so that A. atropos is commonly referred to as the deathshead, or deathshead hawk moth in full.

Close-up of a pinned deathshead hawk moth, showing its skull simulacrum

As can be imagined, its uncanny skull simulacrum has burdened this perfectly innocent insect with a fearful but wholly undeserved reputation as a harbinger of death, doom, and disaster, and has spawned a rich if ridiculous wealth of fanciful rural beliefs and old wives' tales. For example, on occasions when specimens have been observed in a given region just prior to an outbreak of an epidemic disease, the moths have been automatically blamed, and labelled as the messengers of impending mourning. Indeed, many people blamed the entire French Revolution upon the appearance of an unusual number of deathshead moths shortly before its commencement. Moreover, this insect is said in some localities to be in league with witches and to murmur into their ears the names of persons soon to be visited by Death. In central France, it is widely believed that blindness will result if dust particles falling from the wings of a deathshead in flight happen to land in the eyes of anyone watching it...and so on, and so forth.

Spectacular tattoo of a deathshead hawk moth (Matt Gardiner/Flickr)

If these tales were treated lightly, with the humour and contempt that their imaginative but baseless claims deserve, they would constitute nothing more than intriguing yet harmless additions to the annals of modern-day folklore. Tragically, however, for a very long time they have been accepted as truth so wholeheartedly by the credulous and ingenuous that this magnificent moth has been subjected to extensive, barbaric persecution - as revealed graphically by Rev. J.G. Wood's account in his Illustrated Natural History of an all too typical incident that he witnessed during the mid-19th Century:

"I once saw a whole congregation checked while coming out of church, and assembled in a wide and terrified circle around a poor Death's-head Moth that was quietly making its way across the churchyard-walk. No one dared to approach the terrible being, until at last the village blacksmith took heart of grace, and with a long jump, leaped upon the moth, and crushed it beneath his hobnailed feet. I keep the flattened insect in my cabinet, as an example of popular ignorance, and the destructive nature with which such ignorance is always accompanied."

Yet ironically, and despite its eerie thoracic emblem, this much-maligned species was not always so intimately associated in the human mind with death and ill-fortune. Its first English name, apparently given to it in 1773 by nature writer Wilkes, was much more pleasant-sounding - the jasmine hawk moth, after a favoured food-plant of its caterpillar. In 1775, Moses Harris renamed it the bee tyger hawk moth, because of its brown and yellow stripes. 1f only he had been content with this. Sadly, however, in 1778 he changed its name again, this time to the deathshead, which, to its great cost, it has retained ever since. Its scientific name is no less ominous either. Acherontia is derived from Acheron, a river in the underworld of Greek mythology; and Atropos, eldest of the Fates or Moirae, was the black-veiled goddess responsible for cutting every mortal's Thread of Life.

Deathshead hawk moth with wings closed

Acherontia atropos has two close relatives that share its deathhead motif and also have equally doomladen names. Acherontia lachesis (inhabiting the Orient and also the Hawaiian Islands) is named after another of the three Fates, this time Lachesis, who measures out every’s mortal’s Thread of Life, thereby allotting the length of their life.

Acherontia lachesis (Umeshsrinivasan/Wikipedia)

And Acherontia styx (native to the Middle East and eastern Asia) is named after the river of death encircling the Greek underworld.

Acherontia styx

The tenacity of the deathshead’s fallacious notoriety as a winged memento mori has even attracted the attention of the entertainment world. In 1967, Tigon Productions released a UK horror movie entitled 'The Blood Beast Terror', which starred Peter Cushing among others, and concerned a Frankensteinian entomologist of the Victorian era who creates two humans with the ability to transform themselves into giant deathshead moths!

'The Blood Beast Terror' on video (Cobra Video)

This species is also associated with Salvador Dali’s macabre surrealist film ‘Un Chien Andalou’ (1929). And it appears on the cover of Thomas Harris’s chilling novel The Silence of the Lambs (1988), as well as in the official theatrical release posters for the 1991 film adaptation starring Jodie Foster and Anthony Hopkins.

'The Silence of the Lambs' movie poster (Orion Films)

Only a fairly rare spring and summer visitor to Britain, the deathshead A. atropos occurs as a breeding species throughout North Africa and the Middle East and northwards to the Mediterranean. It is resident in parts of southern Europe, and migrates throughout Europe - but cases of breeding have been reported on occasion from Britain, with discoveries of caterpillars in several southern counties. Up to 5 in long, and of robust girth, the impressive-looking deathshead caterpillar varies from several shades of green to lemon, dark brown, or even purple, and is embellished on each flank by seven mauve or azure chevrons, edged decorously with bright yellow or cream. This bold but beautiful colour scheme is topped off with a hazy sprinkling of deep violet or sparkling white dots, and as a final flourish its body's rear end bears a striking curved horn.

Caterpillar of the deathshead hawk moth (Jean Pierre Hamon/Wikipedia)

Pupation takes place underground, the caterpillar digging its way 2-4 in beneath the soil surface and transforming after about a fortnight into a hard, brown, somewhat shiny chrysalis, surrounded by its cocoon of soil, whose function seems to be to maintain the correct degree of humidity around the chrysalis for its successful metamorphosis.

Pupa of the deathshead hawk moth (Walter Schön/Wikipedia)

By late September or early October, metamorphosis is generally complete and the adult moth emerges. Sometimes two generations occur in the same year; the second emerges during November.

Deathshead hawk moth, 19th-Century German print

Whereas the caterpillar thrives upon leaves (especially from the potato), the moth is a fruit-eater primarily - but not exclusively, as beekeepers will verify. Unlike the long slender proboscis ('tongue') of so many other hawk moths, perfectly designed for probing flowers in search of nectar, the deathshead's is much shorter and stouter, adapted instead for piercing the tough outer skin of fruit to obtain their succulent juices. However, it is also well-suited for puncturing the honey-containing cells in beehives, which has enabled the deathshead to expand its dietary scope, and explains why this attractive species is frequently discovered inside hives (as are A. lachesis and A. styx). This is exemplified by a startling discovery made in 1901 by the curator of a marine biology station's museum at Rovigno, Istria. As documented by Alfred Bunbury (The Field, 7 December 1901):

"On the second floor of a house next to this zoological museum is a window whose wooden persienne have for a long time been closed. Though the shutters have been shut, the old wood was full of chinks, and Dr Hermes, the curator of the museum, noticed that a swarm of bees had utilised the space between the window and the shutters for a hive. Curious to see the work of the bees, on Oct. 1 he climbed up to the window, and was astonished to find it covered with death's head moths (Acherontia atropos). The moths, which are extremely fond of honey, had either failed to find their way out of the chinks through which they had entered, or, having fed too heavily on the food, had become dazed in the semi-dark light of the window. Dr Hermes and an assistant made their way into the room by another entrance, and removed a lower pane of the window. Quantities of moths were found hanging on the walls and others on the floor. Many that were dead had evidently been killed by the bees, which had got in under their wings, and those that were still alive were badly mutilated. More than one hundred large specimens were taken that day, and though every day five or six more were found in the same way, by Oct. 13, on which day Dr Hermes was summoned to Berlin, he thought that he had freed the last prisoner. But a few days ago a telegram informed him that 154 moths had again fallen a prey to the bees."

Its liking for honey also appears to explain a characteristic of the deathshead that is every bit as uncanny and superficially unnatural as its thoracic skull sign - namely, it has the highly unexpected and singularly unmoth-like ability to squeak!

Click here to view a photograph of a deathshead hawk moth feeding upon honey inside a honeybee hive (ARKive)

Records of this odd behavioural trait date back at least as far as the 1700s, and its physiological basis has incited much speculation. Some researchers assumed that the squeak was created by friction of the moth's abdomen against its thorax at the junction of these two body portions. Certain others suggested that it occurred if the moth's palps (accessory mouthparts) grated upon its proboscis. It is now known to result from the moth's inhalation of air into its pharynx, causing a stiffened flap (the epipharynx) to vibrate very rapidly.

In their Illustrated Encyclopedia of Beekeeping (1985), Roger Morse and Ted Hooper report that the epipharynx's oscillation yields a pulsed sound of approximately 280 pulses per second for a period of about 80 milliseconds (80 thousandths of one second), followed by a brief pause of 20 milliseconds before the epipharynx is held upwards, enabling the air to be blown out - creating the moth's famous squeak. Lasting a mere 40 milliseconds, it is a very high-pitched sound of about 6 kHz - above the audible range of many humans, though children and acute-eared adults can usually hear it. The moth will perform up to six of these 'squeak-cycles' in as little as one second, but the squeak shortens as the moth tires.

Naturally, there has been much debate about the precise purpose of the deathshead's squeaking. It is certainly a deliberate action, as the moth raises its body when doing so, which enables the sound to be carried to the bees through the air. And as the bees often react by permitting it to enter the hive unmolested (though its tough cuticle is sufficient to withstand occasional stings imparted by any less trusting hive workers, and it is in any case resistant to the venom imparted by such stings), it would seem that its squeaking serves as an effective password. Indeed, some researchers even assert that the moth's squeak is sufficiently similar to the sound made by the hive's queen bee to fool the workers into believing that their queen is instructing them to remain passive. According to this idea, therefore, the deathshead's squeaking is not so much a password as an inspired voice impression!

Deathshead hawk moth, colour engraving from 1840

Moreover, as revealed by R.F.A. Moritz and colleagues, this extraordinary moth is even able to mimic the scent of the honey bees’ cutaneous fatty acids, thus rendering it chemically invisible to them, and so further enabling it to move about freely inside their hives (Naturwissenschaften, vol. 78, 1991).

Intriguingly, writer and photographer Des Bartlett has discovered that in Kenya the presence of deathshead moths inside the beehives comes as a great shock to many of the native Kikuyu people, who seem convinced that they must be some form of wonderful super-queen bee (Animals, 30 July 1963). Also, their unexpected squeaking has been looked upon by all too many Westerners as something ominous or even preternatural - no doubt inspiring the earlier-mentioned myth that this species whispers into the ears of witches.

Polish postage stamp portraying the deathshead hawk moth

All of which brings us back to the subject of superstition, whose anachronistic, irrational utterings of ignorance and fear are still inciting mindless acts of vengeance and violence against this very elegant, showy, and thoroughly harmless insect. Even though we have entered the ultra-scientific 21st Century, there are still people who will not hesitate to kill any deathshead hawk moth that they encounter, atavistically recalling foolish fancies from the centuries of the past.

What can we say to such people? Ironically, the best reply is one that was published almost 150 years ago, but which is still as appropriate today as it was then. To quote from Louis Figuier's The Insect World (1872):

"In spite of its ominous livery, the Atropos does not come from Hades; it is no envoy of death, bringing sadness and mourning. It does not bring us news of another world; it tells us, on the contrary, that Nature can people every hour; that it was her will to console them for their sadness, to grant to the twilight and to the night the same winged wanderers which are at once the delight and ornament of the hours of light and of day. This is the mission of science, to dissipate the thousands of prejudices and dangerous superstitions which mislead ignorant people."

I pray that its mission will succeed, to ensure the survival of the deathshead hawk moth and every other animal currently endangered by the baneful influence of fatuous notions that should have been buried by rationality and compassion a very long time ago.

19th-Century engraving of the deathshead hawk moth

This ShukerNature blog post is excerpted from my book Extraordinary Animals Revisited (CFZ Press: Bideford, 2007)