The Bookworm, and How It Damages Books

By William Blades.

THERE is a sort of busy worm
That will the fairest books deform,
By gnawing holes throughout them;
Alike, through every leaf they go,
Yet of its merits naught they know,
Nor care they aught about them.

Their tasteless tooth will tear and taint
The Poet, Patriot, Sage or Saint,
Not sparing wit nor learning.
Now, if you’d know the reason why,
The best of reasons I’ll supply;
‘Tis bread to the poor vermin.

Of pepper, snuff, or ‘bacca smoke,
And Russia-calf they make a joke.
Yet, why should sons of science
These puny rankling reptiles dread?
‘Tis but to let their books be read,
And bid the worms defiance.”



A most destructive Enemy of books has been the bookworm.  I say “has been,” because, fortunately, his ravages in all civilised countries have been greatly restricted during the last fifty years.  This is due partly to the increased reverence for antiquity which has been universally developed—more still to the feeling of cupidity, which has caused all owners to take care of volumes which year by year have become more valuable—and, to some considerable extent, to the falling off in the production of edible books.

The monks, who were the chief makers as well as the custodians of books, through the long ages we call “dark,” because so little is known of them, had no fear of the bookworm before their eyes, for, ravenous as he is and was, he loves not parchment, and at that time paper was not.  Whether at a still earlier period he attacked the papyrus, the paper of the Egyptians, I know not—probably he did, as it was a purely vegetable substance; and if so, it is quite possible that the worm of to-day, in such evil repute with us, is the lineal descendant of ravenous ancestors who plagued the sacred Priests of On in the time of Joseph’s Pharaoh, by destroying their title deeds and their books of Science.

Rare things and precious, as manuscripts were before the invention of typography, are well preserved, but when the printing press was invented and paper books were multiplied in the earth; when libraries increased and readers were many, then familiarity bred contempt; books were packed in out-of-the-way places and neglected, and the oft-quoted, though seldom seen, bookworm became an acknowledged tenant of the library, and the mortal enemy of the bibliophile.

Anathemas have been hurled against this pest in nearly every European language, old and new, and classical scholars of bye-gone centuries have thrown their spondees and dactyls at him.  Pierre Petit, in 1683, devoted a long Latin poem to his dis-praise, and Parnell’s charming Ode is well known.  Hear the poet lament:--

“Pene tu mihi passerem Catulli,
Pene tu mihi Lesbiam abstulisti.”

 and then—

“Quid dicam innumeros bene eruditos
Quorum tu monumenta tu labores
Isti pessimo ventre devorasti?”

while Petit, who was evidently moved by strong personal feelings against the “invisum pecus,” as he calls him, addresses his little enemy as “Bestia audax” and “Pestis chartarum.”

But, as a portrait commonly precedes a biography, the curious reader may wish to be told what this “Bestia audax,” who so greatly ruffles the tempers of our eclectics, is like.

Here, at starting, is a serious chameleon-like difficulty, for the bookworm offers to us, if we are guided by their words, as many varieties of size and shape as there are beholders.

Sylvester, in his “Laws of Verse,” with more words than wit, described him as “a microscopic creature wriggling on the learned page, which, when discovered, stiffens out into the resemblance of a streak of dirt.”

The earliest notice is in “Micrographia,” by R. Hooke, folio, London, 1665.  This work, which was printed at the expense of the Royal Society of London, is an account of innumerable things examined by the author under the microscope, and is most interesting for the frequent accuracy of the author’s observations, and most amusing for his equally frequent blunders.

In his account of the bookworm, his remarks, which are rather long and very minute, are absurdly blundering.  He calls it “a small white Silver-shining Worm or Moth, which I found much conversant among books and papers, and is supposed to be that which corrodes and eats holes thro’ the leaves and covers.  Its head appears bigg and blunt, and its body tapers from it towards the tail, smaller and smaller, being shap’d almost like a carret. . . . It has two long horns before, which are streight, and tapering towards the top, curiously ring’d or knobb’d and brisled much like the marsh weed called Horses tail. . . . The hinder part is terminated with three tails, in every particular resembling the two longer horns that grow out of the head.  The legs are scal’d and hair’d. This animal probably feeds upon the paper and covers of books, and perforates in them several small round holes, finding perhaps a convenient nourishment in those husks of hemp and flax, which have passed through so many scourings, washings, dressings, and dryings as the parts of old paper necessarily have suffer’d. And, indeed, when I consider what a heap of sawdust or chips this little creature (which is one of the teeth of Time) conveys into its intrals, I cannot chuse but remember and admire the excellent contrivance of Nature in placing in animals such a fire, as is continually nourished and supply’d by the materials convey’d into the stomach and fomented by the bellows of the lungs.”  The picture or “image,” which accompanies this description, is wonderful to behold.  Certainly R. Hooke, Fellow of the Royal Society, drew somewhat upon his imagination here, having apparently evolved both engraving and description from his inner consciousness.

Entomologists even do not appear to have paid much attention to the natural history of the “Worm.”  Kirby, speaking of it, says, “the larvae of Crambus pinguinalis spins a robe which it covers with its own excrement, and does no little injury.” Again, “I have often observed the caterpillar of a little moth that takes its station in damp old books, and there commits great ravages, and many a black-letter rarity, which in these days of bibliomania would have been valued at its weight in gold, has been snatched by these devastators,” etc., etc.

As already quoted, Doraston’s description is very vague.  To him he is in one verse “a sort of busy worm,” and in another “a puny rankling reptile.”  Hannett, in his work on book-binding, gives “Aglossa pinguinalis” as the real name, and Mrs. Gatty, in her Parables, christens it “Hypothenemus cruditus.”

The, Rev. F. T. Havergal, who many years ago had much trouble with bookworms in the Cathedral Library of Hereford, says they are a kind of death-watch, with a “hard outer skin, and are dark brown,” another sort “having white bodies with brown spots on their heads.”  Mr. Holme, in “Notes and Queries” for 1870, states that the “Anobium paniceum” has done considerable injury to the Arabic manuscripts brought from Cairo, by Burckhardt, and now in the University Library, Cambridge.  Other writers say “Acarus eruditus” or “Anobium pertinax” are the correct scientific names.

Personally, I have come across but few specimens; nevertheless, from what I have been told by librarians, and judging from analogy, I imagine the following to be about the truth:--

There are several kinds of caterpillar and grub, which eat into books, those with legs are the larvae of moths; those without legs, or rather with rudimentary legs, are grubs and turn to beetles.

It is not known whether any species of caterpillar or grub can live generation after generation upon books alone, but several sorts of wood-borers, and others which live upon vegetable refuse, will attack paper, especially if attracted in the first place by the real wooden boards in which it was the custom of the old book-binders to clothe their volumes.  In this belief, some country librarians object to opening the library windows lest the enemy should fly in from the neighbouring woods, and rear a brood of worms.  Anyone, indeed, who has seen a hole in a filbert, or a piece of wood riddled by dry rot, will recognize a similarity of appearance in the channels made by these insect enemies.

Among the paper-eating species are:--

1.   The “Anobium.”  Of this beetle there are varieties, viz.:

“A. pertinax,” “A. eruditus,” and “A. paniceum.”  In the larval state they are grubs, just like those found, in nuts; in this stage they are too much alike to be distinguished from one another.  They feed on old dry wood, and often infest bookcases and shelves.  They eat the wooden boards of old books, and so pass into the paper where they make long holes quite round, except when they work in a slanting direction, when the holes appear to be oblong.  They will thus pierce through several volumes in succession, Peignot, the well-known bibliographer, having found 27 volumes so pierced in a straight line by one worm, a miracle of gluttony, the story of which, for myself, I receive “_cum grano salis_.” After a certain time the larva changes into a pupa, and then emerges as a small brown beetle.

2.   “Oecophora.”—This larva is similar in size to that of Anobium, but can be distinguished at once by having legs.  It is a caterpillar, with six legs upon its thorax and eight sucker-like protuberances on its body, like a silk-worm. It changes into a chrysalis, and then assumes its perfect shape as a small brown moth.  The species that attacks books is the OEcophora pseudospretella.

It loves damp and warmth, and eats any fibrous material.  This caterpillar is quite unlike any garden species, and, excepting the legs, is very similar in appearance and size to the Anobium.  It is about half-inch long, with a horny head and strong jaws.  To printers’ ink or writing ink he appears to have no great dislike, though I imagine that the former often disagrees with his health, unless he is very robust, as in books where the print is pierced a majority of the worm-holes I have seen are too short in extent to have provided food enough for the development of the grub.  But, although the ink may be unwholesome, many grubs survive, and, eating day and night in silence and darkness, work out their destiny leaving, according to the strength of their constitutions, a longer or shorter tunnel in the volume.

In December, 1879, Mr. Birdsall, a well-known book-binder of Northampton, kindly sent me by post a fat little Worm, which had been found by one of his workmen in an old book while being bound.  He bore his journey extremely well, being very lively when turned out.  I placed him in a box in warmth and quiet, with some small fragments of paper from a Boethius, printed by Caxton, and a leaf of a seventeenth century book.  He ate a small piece of the leaf, but either from too much fresh air, from unaccustomed liberty, or from change of food, he gradually weakened, and died in about three weeks.  I was sorry to lose him, as I wished to verify his name in his perfect state.  Mr. Waterhouse, of the Entomological department of the British Museum, very kindly examined him before death, and was of opinion he was OEcophora pseudospretella.

In July, 1885, Dr. Garnett, of the British Museum, gave me two worms which had been found in an old Hebrew Commentary just received from Athens.  They had doubtless had a good shaking on the journey, and one was moribund when I took charge, and joined his defunct kindred in a few days.  The other seemed hearty and lived with me for nearly eighteen months.  I treated him as well as I knew how; placed him in a small box with the choice of three sorts of old paper to eat, and very seldom disturbed him.  He evidently resented his confinement, ate very little, moved very little, and changed in appearance very little, even when dead.  This Greek worm, filled with Hebrew lore, differed in many respects from any other I have seen.  He was longer, thinner, and more delicate looking than any of his English congeners.  He was transparent, like thin ivory, and had a dark line through his body, which I took to be the intestinal canal. He resigned his life with extreme procrastination, and died “deeply lamented” by his keeper, who had long looked forward to his final development.

The difficulty of breeding these worms is probably due to their formation.  When in a state of nature they can by expansion and contraction of the body working upon the sides of their holes, push their horny jaws against the opposing mass of paper.  But when freed from the restraint, which indeed to them is life, they CANNOT eat although surrounded with food, for they have no legs to keep them steady, and their natural, leverage is wanting.

Considering the numerous old books contained in the British Museum, the Library there is wonderfully free from the worm.  Mr. Rye, lately the Keeper of the Printed Books there, writes me “Two or three were discovered in my time, but they were weakly creatures.  One, I remember, was conveyed into the Natural History Department, and was taken into custody by Mr. Adam White who pronounced it to be Anobium pertinax.  I never heard of it after.”

The reader, who has not had an opportunity of examining old libraries, can have no idea of the dreadful havoc which these pests are capable of making.

I have now before me a fine folio volume, printed on very good unbleached paper, as thick as stout cartridge, in the year 1477, by Peter Schoeffer, of Mentz.  Unfortunately, after a period of neglect in which it suffered severely from the “worm,” it was about fifty years ago considered worth a new cover, and so again suffered severely, this time at the hands of the binder.  Thus the original state of the boards is unknown, but the damage done to the leaves can be accurately described.

The “worms” have attacked each end.  On the first leaf are 212 distinct holes, varying in size from a common pin hole to that which a stout knitting-needle would make, say, <1/16> to <1/23> inch.  These holes run mostly in lines more or less at right angles with the covers, a very few being channels along the paper affecting three or four sheets only.  The varied energy of these little pests is thus represented:--

On folio 1 are 212 holes.  On folio 61 are 4 holes.

        “   11  “   57   “         “    71  “  2   “

        “   21  “   48   “         “    81  “  2   “

        “   31  “   31   “         “    87  “  1   “

        “   41  “   18   “         “    90  “  0   “

        “   51  “    6   “



These 90 leaves being stout, are about the thickness of 1 inch. The volume has 250 leaves, and turning to the end, we find on the last leaf 81 holes, made by a breed of worms not so ravenous.  Thus,

      From end                    |         From end.

 On folio 1 are 81 holes.     |    On folio 66 is 1 hole.

     “   11 “   40   “             |         “   69   “   0   “


 It is curious to notice how the holes, rapidly at first, and then slowly and more slowly, disappear.  You trace the same hole leaf after leaf, until suddenly the size becomes in one leaf reduced to half its normal diameter, and a close examination will show a small abrasion of the paper in the next leaf exactly where the hole would have come if continued. In the book quoted it is just as if there had been a race.  In the first ten leaves the weak worms are left behind; in the second ten there are still forty-eight eaters; these are reduced to thirty-one in the third ten, and to only eighteen in the fourth ten.  On folio 51 only six worms hold on, and before folio 61 two of them have given in.  Before reaching folio 7, it is a neck and neck race between two sturdy gourmands, each making a fine large hole, one of them being oval in shape. At folio 71 they are still neck and neck, and at folio 81 the same. At folio 87 the oval worm gives in, the round one eating three more leaves and part way through the fourth. The leaves of the book are then untouched until we reach the sixty-ninth from the end, upon which is one worm hole. After this they go on multiplying to the end of the book.  

I have quoted this instance because I have it handy, but many worms eat much longer holes than any in this volume; some I have seen running quite through a couple of thick volumes, covers and all. In the “Schoeffer” book the holes are probably the work of Anobium pertinax, because the centre is spared and both ends attacked. Originally, real wooden boards were the covers of the volume, and here, doubtless, the attack was commenced, which was carried through each board into the paper of the book.

I remember well my first visit to the Bodleian Library, in the year 1858, Dr. Bandinel being then the librarian. He was very kind, and afforded me every facility for examining the fine collection of “Caxtons,” which was the object of my journey. In looking over a parcel of black-letter fragments, which had been in a drawer for a long time, I came across a small grub, which, without a thought, I threw on the floor and trod under foot. Soon after I found another, a fat, glossy fellow, so long ---, which I carefully preserved in a little paper box, intending to observe his habits and development.  Seeing Dr. Bandinel near, I asked him to look at my curiosity.  Hardly, however, had I turned the wriggling little victim out upon the leather-covered table, when down came the doctor’s great thumb-nail upon him, and an inch-long smear proved the tomb of all my hopes, while the great bibliographer, wiping his thumb on his coat sleeve, passed on with the remark, “Oh, yes! they have black heads sometimes.”

That was something to know—another fact for the entomologist; for my little gentleman had a hard, shiny, white head, and I never heard of a black-headed bookworm before or since. Perhaps the great abundance of black-letter books in the Bodleian may account for the variety.  At any rate he was an Anobium.  

I have been unmercifully “chaffed” for the absurd idea that a paper-eating worm could be kept a prisoner in a paper box.  Oh, these critics! Your bookworm is a shy, lazy beast, and takes a day or two to recover his appetite after being “evicted.”  Moreover, he knew his own dignity better than to eat the “loaded” glazed shoddy note paper in which he was incarcerated.  

In the case of Caxton’s “Lyf of oure ladye,” already referred to, not only are there numerous small holes, but some very large channels at the bottom of the pages.  This is a most unusual occurrence, and is probably the work of the larva of “Dermestes vulpinus,” a garden beetle, which is very voracious, and eats any kind of  dry ligneous rubbish.  

The scarcity of edible books of the present century has been mentioned. One result of the extensive adulteration of modern paper is that the worm will not touch it.  His instinct forbids him to eat the china clay, the bleaches, the plaster of Paris, the sulphate of barytes, the scores of adulterants now used to mix with the fibre, and, so far, the wise pages of the old literature are, in the race against Time with the modern rubbish, heavily handicapped.  Thanks to the general interest taken in old books now-a-days, the worm has hard times of it, and but slight chance of that quiet neglect which is necessary to his, existence.  So much greater is the reason why some patient entomologist should, while there is the chance, take upon himself to study the habits of the creature, as Sir John Lubbock has those of the ant.  

I have now before me some leaves of a book, which, being waste, were used by our economical first printer, Caxton, to make boards, by pasting them together.  Whether the old paste was an attraction, or whatever the reason may have been, the worm, when he got in there, did not, as usual, eat straight through everything into the middle of the book, but worked his way longitudinally, eating great furrows along the leaves without passing out of the binding; and so furrowed are these few leaves by long channels that it is difficult to raise one of them without its falling to pieces.  

This is bad enough, but we may be very thankful that in these temperate climes we have no such enemies as are found in very hot countries, where a whole library, books, bookshelves, table, chairs, and all, may be destroyed in one night by a countless army of ants.  

Our cousins in the United States, so fortunate in many things, seem very fortunate in this—their books are not attacked by the “worm”—at any rate, American writers say so. True it is that all their black-letter comes from Europe, and, having cost many dollars, is well looked after; but there they have thousands of seventeenth and eighteenth century books, in Roman type, printed in the States on genuine and wholesome paper, and the worm is not particular, at least in this country, about the type he eats through, if the paper is good.  

Probably, therefore, the custodians of their old libraries could tell a different tale, which makes it all the more amusing to find in the excellent “Encyclopaedia of Printing,” edited and printed by Ringwalt, at Philadelphia, not only that the bookworm is a stranger there, for personally he is unknown to most of us, but that his slightest ravages are looked upon as both curious and rare.  After quoting Dibdin, with the addition of a few flights of imagination of his own, Ringwalt states that this “paper-eating moth is supposed to have been introduced into England in hogsleather binding from Holland.”  He then ends with what, to anyone who has seen the ravages of the worm in hundreds of books, must be charming in its native simplicity.  “There is now,” he states, evidently quoting it as a great curiosity, “there is now, in a private library in Philadelphia, a book perforated by this insect.” Oh! lucky Philadelphians! who can boast of possessing the oldest library in the States, but must ask leave of a private collector if they wish to see the one wormhole in the whole city! 


Update: Laura K. wrote in with the following information;

I just read William Blades' article on your site about book "worms."
I wanted to send some additional info your way.  I grew up in Florida in a termite/bug-infested house. We didn't have a television, but we did have many books with which to entertain ourselves. I quite often caught termites in the act of stealing a free lunch from my books ( Also, one of the pests that is described as being silverish with three tails is locally called a silverfish or firebrat (darker than a silverfish) ( Silverfish will eat the paper and glued binding.

Thank you, Laura, for providing this additional information. 


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