THE LONGEST INSECTS IN THE WORLD

The shortest (and least serious) article that I've ever written was about the longest insects in the world. I wrote it to see how easy it would be to get something published in the East Africa Natural History Society Bulletin. 'A Stick Insect in Same' was published in September 1991, and here's the text in full:

In early September 1990, while staying in Same (between the North and South Pare Mountains) in north-east Tanzania, I stumbled upon what was by far the longest stick-insect that I have ever seen. It was clinging to the sides of some cement steps, and at first I mistook it for a growth of leafless twigs. Not until I saw that these grey twigs were perfectly symmetrical and growing out of nothing did it dawn on me that I might be looking at a living creature. I showed it to some of my colleagues, members of local women's groups, and they were only convinced of its real identity once they had frightened it into moving. Like me they were astounded by its size, and all of them declared that they had never seen anything like it before. They were, indeed, somewhat alarmed, and killed it with a few well-aimed rocks.

I had all but forgotten about this incident until recently, when I came across the following statement in last year's edition of The Guinness Book of Records (p.40): "The longest insect in the world is the Giant Stick Insect Pharnacia serratipes of Indonesia, females of which have been measured up to 330 mm (13 inches)". How I wish that I had made use of a tape measure and camera that day! I could swear that my Same stick insect was much the same size as the longest of its Indonesian cousins. It was certainly much longer than the norm - or what I suppose to be the norm in my ignorance of the relevant entomological records. I would be very happy for someone to write and enlighten me. Otherwise, and not just for those with an eye to the record books, I would recommend a visit to the hostel recently opened by the Roman Catholic Diocese of Same. The hostel buildings enclose a small garden, host (one hopes) to the relatives of a very long, but unfortunately very dead, stick insect. (Walsh 1991)

A couple of months later, in November 1991, I found a dead stick insect in our swimming pool in Nyali, on the north coast of Mombasa. It wasn't quite as big as the one I'd written about, but, with a body length of 180 mm and an overall length (including legs) of around 291 mm, it was impressive enough (the photograph and sketches shown here are of this apparently drowned specimen). The next week I bought a second-hand copy of Pinhey and Loe's introductory text, A Guide to the Insects of Africa (1974), with Ian Loe's illustration of the Congolese Palophus leopoldi (= Bactrododema leopoldi (Schouteden, 1916)) on its cover. This looked superficially similar to my Nyali stick, but was evidently a much longer species, described as the largest stick insect in Africa, "which, with legs stretched out in front and behind, measures over 400 mm" (1974: 20).

Then, searching for better sources in the library of the National Museum and East Africa Natural History Society in Nairobi, I discovered an old reference to large stick insects in the vicinity of Lohumbo in Shinyanga District in (what was then) Tanganyika:  a report of a male "which measured fifteen and a half inches from the tips of the front legs to the tips of the hind legs", and a collected female specimen, tentatively identified as Palophus episcopalis (= Bactrododema episcopalis (Kirby, 1896)), whose total length was "just over fourteen inches" (Carpenter 1942: 75). At c.394 mm the male was reputedly almost as long as the Congolese record-holder. And both of these African Palophus (= Bactrodema) were longer than the 330 mm that The Guinness Book of Records gave for the Asian Pharnacia serratipes (= Giant Malayan Stick Insect, Phobaeticus serratipes (Gray, 1835)) (McFarlan 1989: 40).

I therefore wrote to the Editor of The Guinness Book of Records drawing his attention to the different measurements and enclosing photocopies of my article and the two sources on African stick insects that I'd found. I ended my letter by noting that "Unless the basis for these measurements is different, or they are simply wrong, then it appears that the Palophus of Africa should be described as the longest insects in the world" (Mombasa, 4 December 1991). In reply I received a courteous letter from the Deputy Editor, Maria Morgan, thanking me for my observations and promising to follow up on them: "It may be that the methods of measurement differ slightly but your letter will receive our fullest consideration and the entry will of course be amended if necessary" (Enfield, Middlesex, 6 January 1992). Much to my surprise the next edition of The Guinness Book of Records was changed to read: "The longest insects in the world are stick-insects (walking sticks), especially of the African species [sic] Palophus, which can attain lengths of 400 mm 15¾ in in the case of Palophus leopoldi" (Matthews 1992: 38). It looked as though this had been done without reference to proper scientific authorities, but merely in response to my amateur intervention and ultimately on the basis of the sketchy description in an introductory guide.

The African pretender, Palophus leopoldi (= Bactrododema leopoldi (Schouteden, 1916)), reigned supreme for two years, through to the 40th edition of The Guinness Book of Records (Matthews 1993: 41). Back in England I corresponded with Paul Brock, the Treasurer and Membership Secretary of the Phasmid Study Group, and became PSG Member No.1234. Stuck in a dull academic job, I dreamed of searching for more East African stick insects, until I was discouraged by the discovery that reference materials were few and far between and often difficult to find. This was compounded by the realisation that scientific collecting and study would require the kind of dedication and expertise that I singularly lack.

I planned an early version of this note, describing how the entry in The Guinness Book of Records had been changed without any real evidence, and making the point that the interesting scientific question was not how long particular species and specimens were, but how and why some stick insects had evolved to such large sizes. Using the few sources at my disposal, including Brock (1992), I drew up a table of the reported lengths of the longest stick insects. As soon as I did this, it dawned on me that two different measurements were being reported in the literature, body length and the total length including the outstretched legs. The earlier records in The Guinness Book of Records were based on body length (330 mm for Pharnacia serratipes), whereas the reports for Palophus spp. that I'd found were based on overall length (e.g. 400 mm for P.leopoldi). It may be that some of the African Palophus (= Bactrododema) had bodies equal or greater in length to the Asian Pharnacia (= Phobaeticus), but there was no actual evidence for this. When writing to The Guinness Book of Records I'd expressed some caution about the basis for different measurements, and now it turned out that I was right to do so.

In the summer of 1994 I returned to East Africa and forgot about my phasmid fantasies. The next edition of The Guinness Book of Records gave primacy to Pharnacia kirbyi (= Phobaeticus kirbyi Brunner von Watenwyl, 1907), a species from Borneo. Although I didn't know it at the time, phasmid researcher Phil Bragg had published a paper in The Entomologist pointing out that the original record was based on a misidentification, and that the African record was based on the measurement of overall rather than body length (1995: 26). I didn't see another large stick insect until one day in May 2002, driving from Dar es Salaam to Iringa in a project Landrover. As we sped along the road approaching Kitonga I caught sight of a very large stick crossing in front of us, heading into the bush northwards. We were travelling at 110-120 km per hour, and I had a split second in which to ask the driver, Aston, to slam on the brakes. I thought of the hassle, hesitated, and the moment had gone. Gone too, I mused, was my chance to change the record books again, this time with some real evidence. Instead the world record is now held by another Bornean species, recently described by Phil Bragg (Chan's Megastick, Phobaeticus chani Bragg, 2008) and displayed in the Natural History Museum in London.  

Afterword, 20 August 2010

Martyn Tovey has kindly gone through different editions of The Guinness Book of Records (and its successors) and painstakingly examined the entries for the world's longest insect. His analysis shows a surprising number of changes, updates, and errors. One change is of particular significance to my own tale: whereas early editions had all made it clear that the principal measurements given referred to the body length of stick insects, this detail was omitted from the 29th edition (published in 1982) onwards, and wasn't reintroduced until the 41st edition (1994), which picked up on Phil Bragg's observations. Martyn's notes are reproduced with minor amendments below. For details of the different editions and their dates of publication readers are referred to his wonderful Guinness Record Book Collecting website.

The longest insect record appeared in the very first edition in 1955 (under Insects, Largest), as:
Some tropical stick-insects (Plasmidae) have a body length up to 13 inches (330 mm.) [p.34]

The entry was slightly modified in the 2nd edition in 1956 (now known as the 5th edition):
Some tropical stick-insects (Phasmidae) have a body length up to 13 inches (330 mm.) [p.30]

The 10th edition (1962) has:
Some tropical stick-insects (Phasmidae) have a body length up to 13 inches (330 mm.) and in the case of the Palophus titan from Australia a wing span of 10 inches. [p.29]

The description changes slightly for the 13th edition in 1966:
Some tropical stick-insects (family Phasmidae) have a body length up to 13 inches and in the case of the Palophus titan from Australia a wing span of 10 inches. [p.35]

In the 18th edition (1971), the record changes again to:
Some tropical stick-insects have a body length of up to 13 inches (e.g. Phoboeticus fruhstorferi) and, in the case of Palophus titan from Australia, a wing span of 10 inches. [p.41]

The next (19th edition) moves the record into its own category (Insects, Longest):
The longest insect in the world is the tropical stick-insect Pharnacia serratipes, females of which have been measured up to 33 cm (12.99 inches) in body length. [p.42]

In edition 28, published in 1981, the record becomes:
The longest insect in the world is the giant stick-insect Pharnacia serratipes of Indonesia, females of which have been measured up to 330 mm (13 inches) in body length. [p.46]

The 29th edition had a reference to the record in the usual place, but the actual record was shown in a two-page table of "Superlatives of the Animal Kingdom". It omitted the detail "in body length". The table appeared in the 30th, 31st, 32nd and 33rd editions. For the 34th edition (published 1987), the record was back in the main text as:
The longest insect in the world is the Giant stick-insect (Pharnacia serratipes) of Indonesia, females of which have been measured up to 330 mm 13 in. [p.39]

The record in the 39th edition is:
The longest insects in the world are stick-insects (walking sticks), especially of the African species Palophus, which can attain lengths of 400 mm 15¾ in in the case of Palophus leopoldi. [p.38]

The record changes in the 41st edition to:
The longest recorded insect in the world is Pharnacia kirbyi, a stick insect from the rainforests of Borneo. The longest-known specimen is in the British Natural History Museum in London, UK: it has a body length of 328 mm 12.9 in and a total length, including the legs, of over half-a-metre 20 in.

The total length is given as 546 mm (20 inches) in the 42nd edition, but 54.6 cm (21.5 inches) in the 43rd. The 1999 44th edition (published in 1998) has a picture of the specimen from the Natural History Museum (pp.258-259). The 2008 54th edition updates the record:
Two stick insects share this record, depending on how they are measured. Pharnacia kirbyi is a stick insect from the rainforests of Borneo. The longest specimen known had a body length of 32.8 cm (12.9 in) and a total length, including the legs, of 54.6 cm (21.5 in). This makes it the longest insect in the world based on head-plus-body length. A specimen of Malaysia's Phobaeticus serratipes had a head-plus-body length of 27.8 cm (10.9 in), but when its outstretched legs were included, it measured a record 55.5 cm (21.8). [p.45]

The 2010 56th edition (published in 2009) has a new entry:
On 16th October 2008, the UK's Natural History Museum announced a new holder for the record of the longest stick insect: Phobaeticus chana - aka Chan's megastick - from the rainforests of Borneo. The longest of the three known specimens [...] measured 56.6 cm (22.3 in) with its legs stretched; its body alone measured 35.5 cm (14 in) - also a record for the insect class. [p.48]

Paul Brock adds that in his opinion "an Australian species Ctenomorpha gargantua Hasenpusch & Brock, 2006 will compete for the 'longest insect in the world' title, as they are over 300mm".

Acknowledgements
I remain very grateful to Paul Brock for his correspondence in 1993-94 and for taking the trouble to send me hard-to-obtain literature on phasmids. I'm sorry that I've been able to make no better use of it than this! Thanks also to James Walsh for his photograph and drawing of the stick insect (very likely Bactrododema sp.) that appeared in our swimming pool that Sunday morning in 1991. Martyn Tovey and, again, Paul Brock are thanked for their contributions to the Afterword.

References

Bragg, P. E. 1995. The Longest Stick Insect in the World, Pharnacia kirbyi (Brunner). The Entomologist 114 (1): 26-30.

Bragg, P. E. 2008. In Frank H. Hennemann and Oscar V. Conle, Revision of Oriental Phasmatodea: The Tribe Pharnaciini Günther, 1953, Including the Description of the World's Longest Insect, and a Survey of the Family Phasmatidae Gray, 1835 with Keys to the Subfamilies and Tribes (Phasmatodea: "Anareolatae": Phasmatidae), Zootaxa 1906.

Brock, Paul D. 1992. Rearing and Studying Stick and Leaf-Insects (The Amateur Entomologist 22). Feltham, Middlesex: The Amateur Entomologists' Society.

Brock, Paul D. 2004. Taxonomic Notes on Giant Southern African Stick Insects (Phasmida), including the Description of a New Bactrododema Species. Annals of the Transvaal Museum 41: 61-77.

Carpenter, G. D. Hale 1942. Notes by E. Burtt, B.Sc., F.R.E.S., on a Species of Palophus (Probably episcopalis Kirby): A Giant Phasmid (Orthoptera) from Tanganyika Territory. Proceedings of the Royal Entomological Society of London (A) 17 (7-9): 75-76.

McFarlan, Donald (ed.) 1989. The Guinness Book of Records 1990 (36th edition). Enfield, Middlesex: Guinness Publishing Ltd.

Matthews, Peter (ed.) 1992. The Guinness Book of Records 1993 (39th edition). Enfield, Middlesex: Guinness Publishing Ltd.

Matthews, Peter (ed.) 1993. The Guinness Book of Records 1994 (40th edition). Enfield, Middlesex: Guinness Publishing Ltd.

Pinhey, Elliot and Ian D. Loe 1974. A Guide to the Insects of Africa. Hamlyn: London.

Walsh, Martin 1991. A Stick Insect in Same. East Africa Natural History Society Bulletin 21 (3): 48.