Some Australian Spider HistoryThe contents of this page are intended to provide a brief review of the important events that have occurred in Australian spider research since this country was first colonized by Britain in the late 18th century. It has two distinctly different sections to it, the first dealing with the naming of the spiders of Australia and the second involving studies of Australian spider venoms, their toxic actions on mammals, and their potential uses as insecticides.
A BRIEF REVIEW OF THE HISTORY OF AUSTRALIAN SPIDER TAXONOMY
It is difficult to be sure which Australian spider was the next to be formally named. One likely candidate is Nephila edulis which was allegedly described in 1799 as Aranea edulis by Jacques Labillardiere then renamed Nephila edulis by Charles Walckenaer in 1841. Walckenaer is also credited with naming Missulena occatoria in 1805 and since this species is believed to be unique to Australia it is possible that it was the third Australian spider to be formally described. However, awarding the 'bronze medal' to Missulena occatoria is problematical in that former Queensland Museum arachnologist, Valerie Davies, has reported that the specimen used by Walckenaer was part of a collection made in Australia by naturalists from a French ship in 1802 and this same collection probably also contained the sparassid Delena cancerides and the zodariid Storena cyanea since Walckenaer formally named all three species. If this was indeed the case it illustrates the fact that many Australian spiders were actually described and named long after they had been collected.
Many other Australian spiders were given scientific names during the 19th century. It appears that most of these were first collected or maybe just described by Europeans although at least two notable British arachnologists, Octavius Pickard-Cambridge and Henry R. Hogg were also involved. Hogg started collecting spiders in Australia about 1873 but apparently did not publish any formal spider names until after 1900. Cambridge named a variety of spiders, including species of the thomisid Amyciaea, the araneid Celaenia, and the theridiid Argyrodes, as well as the famous Sydney funnel-web spider, Atrax robustus. It might be assumed that during the 19th century European spider experts travelled all over Australia collecting and naming spiders no one had ever heard of before. While this could be at least partly true it is also likely that many undescribed species were simply placed in preservative fluid by unnamed people and taken to Northern Hemisphere museums for classification by expert arachnologists. In addition, some spider species that are now common in Australia are also found in countries north of the Australian mainland so in some cases the holotype specimen (the one used to describe the species) could have been collected elsewhere, bearing in mind that Ferdinand Magellan passed through the East Indies during his 1519-1522 circumnavigation of the earth and the Portugese and British were enjoying Chinese tea as early as the 16th and 17th centuries.
FAMOUS AUSTRALIAN ARACHNOLOGISTS
One person who stands out as having played an incredible role in the classification of Australian spiders in the latter half of the 19th century was Ludwig Koch. An extraordinary number of Australian spiders are listed by the World Spider Catalog as having been formally named by him. This is illustrated in the following list of spider family names, each with just one example of a genus examined by Koch within each family (Note: the generic and even the family name listed may be revised ones adopted long after Koch's death):
But does this mean that Koch and Keyserling spent large amounts of time on numerous visits to Australia to collect and classify our spiders? On the contrary, the available historical evidence, though limited and uncertain, strongly suggests that neither arachnologist ever actually visited Australia. They had no need to. In 1861 a wealthy German shipping magnate named Johann Godeffroy established the Museum Godeffroy in Hamburg to house zoological and other specimens his ships brought back from Australia and some South Seas countries. Having a keen interest in nature Godeffroy apparently placed on each of his ships people who knew how to collect and preserve spider specimens in alcohol and who were requested to search for specimens at each foreign port their ship entered. These specimens gradually accumulated in his museum and were there for Koch and others to describe and name. This greatly reduced the need for them to go off on extended spider searches of their own.
Other arachnologists to create names for some common Australian spiders during the latter part of the 19th century were Octavius Pickard-Cambridge (commonly just shown as Cambridge), the Swede Tamelan Thorell, and the Frenchman Eugene Simon. However, during the last decade of the 19th century and for the first 19 years of the 20th century one person who stands out as an arachnologist heavily involved in describing Australian spiders was William Rainbow. Although born in England and raised in New Zealand Rainbow spent most of his life in Sydney and was very active in describing spiders. Not only did he classify a considerable number of new species but he claimed, probably correctly, to be the first person to make a comprehensive list of the known Australian spider species. This was published in 1911 in Volume 9 of the journal Records of the Australian Museum and it included a remarkable 285 genera from 24 families to make a total of approximately 1200 species. Rainbow even provided information as to who named each species and where it was found, details which even today's World Spider Catalog considers to be important. Sadly, Rainbow made what is now a major taxonomic error: he named his list A Census of Australian Araneidae but it included both araneomorph and mygalomorph species so the list was actually of Australian Araneae (the true spiders), the term Araneidae now referring only to a single araneomorph family. Of course, Rainbow did recognize the existence of a family of web-weaving spiders but he called it the Argiopidae, a name that continued to be accepted at least until the 1980s.
SPIDER TAXONOMY IN AUSTRALIA IN THE TWENTIETH CENTURY
For the first few decades of the 20th century many other arachnologists were actively describing Australian spiders, including the medically qualified Robert Pulleine, (who collaberated with Rainbow during the last part of the latter's life), Eugene Simon, H.R. Hogg, and V.V. Hickman, the last of these comprehensively studying the spiders of Tasmania. Of course, the published works of all of the arachnologists mentioned so far were limited by the circumstances of that time. Thus, it was virtually impossible for them to include photos in their publications and the drawings they did provide were really too primitive to be of much use to a 21st century arachnologist. They concentrated on describing the anatomy of each spider and frequently added little or no information about its habitat, diet, behavioural patterns and range. In addition, because so many of the early arachnologists working on Australian spiders were from Britain and Europe, many of the early generic names were 'borrowed' from equivalent Northern Hemisphere species. For example, they found plenty of orb-weaving species and named some of them Araneus species because the Araneus genus was well known in the Northern Hemisphere. However, while they looked similar to British and European species and occupied similar habitats they were sufficiently different in anatomical characters to justify the erecting of new, uniquely Australian generic names for them. It is for this reason that many recent revisions of Australian spiders have involved renaming of quite a few genera, although there has lately been a tendency to revert to the original generic names because of the present taxonomic rules. For example, Aname tepperi (Hogg, 1902) changed to Chenistonia tepperi (Main, 1964) then back to Aname tepperi (Raven, 2000).
The decades since world War II have also seen some other major changes in the publications of Australian arachnologists. A number of people decided to make information on spiders more available to members of the general public in book form. Keith McKeown had already published Spider Wonders of Australia in 1936 and Barbara York Main's 1960 Spiders of Australia field guide was comprehensive yet small enough that naturalists could use it in the field to identify the family and even the genus of the more common Australian spiders they happened to find. It included some useful black-and-white drawings and even a basic family key. A somewhat similar book, Australian Spiders, published in 1965 by John Child, did not have a key but was one of the first to include colour photos of many spiders. It also put more emphasis on the anatomy and behaviour of common spiders rather than on their classification.
From 1969 to 1977 Densey Clyne published several versions of A Guide to Australian Spiders and these books were all well accepted because of the high quality of the photos they contained. With the assistance of a skilled cinematographer named Jim Frasier Clyne also produced some excellent colour films on Australian spiders. Unfortunately, these are now very difficult to access. And finally, Ramon Mascord deserves special mention because of the enormous respect he received due to the high quality of his work on spiders. Following service in the A.I.F. during world War II Mascord worked as a book illustrator and in the process gradually became a spider expert highly regarded even by the museum arachnologists of that time. Over the period at least to 1980 he produced several books containing information and colour photos of most of the Australian spiders that had been described so far. Many of the taxonomic names he used in his books have since been changed by more recent revisions of spider families and genera but this by no means diminishes the quality of his work as an archnologist.
The period from 1980 to the present has been a time when many Australian arachnologists have been busy naming undescibed members of Australian spider families and reviewing the conclusions of earlier taxonomists. So prolific has this work been that it would be unnecesssarily tiresome to attempt to list all of the participants and the families or genera they worked on. The following list will therefore include only those people who are recognized as having contributed in a major way to the final resolution of the main Australian spider families. For almost every family there were other scientists who also added significant information and the fact that their names are not shown on the list is in no way intended to denigrate the contribution each of them has made. But having regard to the remarkably large number of spider families about which people like Robert Raven and Barbara York Main published significant amounts of new information they surely deserve special mention. For each of the families on the list the approximate year(s) in which the taxonomist named is recorded as having carried out and published his or her contribution is shown in brackets:
ARANEIDAE: Valerie T. Davies (1988), Memoirs of the Queensland Museum, 25, 273-332.
CORINNIDAE: Robert J. Raven (2015), Zootaxa 3958.
DIPLURIDAE AND NEMESIIDAE: Robert J. Raven (1981), Australian Journal of Zoology 29, 321-363 and(1984) Arachnology 12, 177-193.
HERSILIIDAE: Barbara Baehr and Martin Baehr (1993) Records of the Western Australian Museum 16(3), 347-391.
HEXATHELIDAE: Michael R. Gray (2010) Records of the Australian Museum 62(3), 285-392.
IDIOPIDAE: Barbara York Main and Graham Wishart (Numerous papers from 1960 to the present time)
LAMPONIDAE: Norman Platnick (2000) Bulletin of the American Museum of Natural History, No. 245.
LYCOSIDAE: Volker Framenau (2017) Accessible at www.lycosidae.info/identification/australia/firstpage.html
NICODAMIDAE: Mark Harvey (1995) Invertebrate Taxonomy, 9, 279-386.
OXYOPIDAE: Judith Grimshaw (1989) University of Queensland Doctor of Philosophy thesis.
PHOLCIDAE: Bernhard Huber (2001) Bulletin of the American Museum of Natural History, No.260.
PISAURIDAE: Robert Raven (revision occurring 2017 - 2018)
SALTICIDAE: Marek Zabka and Valerie Davies (1989) Memoirs of the Queensland Museum 27(2), 189-266.
TETRAGNATHIDAE: Chiyoko Okuma (1987)
THERIDIIDAE: Herbert and Lorna Levi (1962) Bulletin of the Museum of Comparative Zoology, 27(1).
THOMISIDAE: Pawel Szymkowiak (2007) Proceedings of the 8th Conference of the Polish Taxonomic Society, 18-20.
ZODARIIDAE: R. Jocque and B Baehr (2001) Records of the Australian Museum, 53(1), 21-36.
OTHER ARACHNIDS: Mark Harvey (1981) Bulletin of the British Arachnological Society, 5(6), 237-252.
COLLATING AND UPDATING AUSTRALIA'S SPIDER NAMES
Over the period in which the arachnologists in the above list have been active a gradual improvement in the techniques used to describe and illustrate the spiders of Australia has occurred. Anatomical drawing skills improved and were progressively supplemented by black-and-white images then colour photos followed by scanning electron micrographs and eventually DNA analyses. These later techniques revealed information that led to some substantial changes (and arguments) in regard to the correct scientific names of many spiders and in the lineage (families and clades) to which they belong. This has caused a great deal of confusion as older publications contain more and more incorrect information but it is hoped that eventually the worst of this revising will be over and spider names should then remain the same for a long period of time.
Despite the efforts of Main in her 1960 pocket field guide and Mascord in his 1970 and 1980 spider books many spider enthusiasts have regretted the apparent lack of a comprehensive taxonomic key for the spiders of Australia. Keys for small families or genera within single families are usually included with each published revision paper but an overall key seems not to be achievable while the Australian spider taxonomy is in such a volatile state. In 2002 Robert Raven, Barbara Baehr and Mark Harvey produced a CD-ROM entitled Spiders of Australia. Interactive Identification to Subfamily but, as the title indicates, this only served to classify spiders to family or sometimes to subfamily and the on-going revisions soon caused this CD-ROM to lose much of its usefulness.
At the international level Carl-Friedrich Roewer over the period 1939-1954 produced in three volumes a classification of the world's known spiders. His 1955 volume Katalog der Araneae von 1758 bis 1940 was nearly a thousand pages long. When in 1986 Normal Platnick created the on-line World Spider Catalog he largely followed Roewer's system despite the fact that he is said to have been critical of some of Roewer's generic placements. The World Spider Catalog continues to exist today although Platnick is no longer in charge of it. Listed are the names of the described spiders from all countries, including Australia, the places where each species is known to be present, and the person who named it. However, the Catalog does not provide a classification key and accepts whatever taxonomic changes are published in new peer-reviewed research papers.
Some attempts have also been made to provide catalogues that contain only Australian spiders. Perhaps the most noteworthy example was the Zoological Catalogue of Australia Volume 3 Arachnida which was published in 1985 as an Australian Government initiative. It had three sections: the Mygalomorphae, compiled by Barbara York Main; the Araneomorphae, the work of Valerie Todd Davies with some help from R.J. McKay; and the Pseudoscorpionida, compiled by Mark Harvey. This catalogue gave an introductory description of each family followed by some very good information about who named each species and where it was found. The main disappointment for the reader of this catalogue is that Davies deliberately omitted 18 major families which collectively contain about 70 percent of Australia's described araneomorph species, her reasons being that many of the omitted families were still in need of major revisions and would also have made the catalogue excessively large for production as a single volume. Unfortunately, no additional volume to correct this omission was ever produced.
THE ROLE OF THE GENERAL PUBLIC IN AUSTRALIAN SPIDER TAXONOMY
There are many Australian species of spiders (as well as plants and other animals) still out there waiting to be found and formally named. Over the last couple of decades Bush Blitz teams of biologists, including staff from the CSIRO and many Australian universities and museums, have performed multiple collecting surveys of parts of Australia. But despite funding by the Federal Government, the Earthwatch Institute, and commercial organisations such as BHP Billiton, even these experienced arachnologists have not been able to find every spider species that is out there because many spiders that are comparatively rare are only likely to be discovered by pure chance. Fortunately, in recent years there has been an increasing tendency for members of the general public to play a role in the naming of previously unknown Australian spider species.
Of course, people with little or no scientific training will usually only be able to identify a particular spider by its trivial name (such as trapdoor, wolf, or jumping spider), a highly qualified arachnologist being needed to create a new generic or species name when required and to publish this in a peer-reviewed journal. Fortunately, it is now much easier to post specimens to museums and the staff there are always pleased to receive a living or well preserved specimen, especially of a species they have not seen before, and this increases the number of known species or extends the known range of species that have already been named. Then when each new species is eventually described in a scientific paper the author of the paper will normally state where it was found and often the name of the person who found it. Some lucky people even have the spider named after them.
From about the start of the present millenium several new ways the public can contribute to our overall knowledge of the spiders of Australia have become available. Websites that people can submit spider or other biological photos to have now been launched. One of the first was Flickr.com (2004) which allows people to display photos on the internet for others to see and perhaps help identify. The CSIRO-derived website, the Atlas of Living Australia (ALA), was launched about 2010 with the intention of providing information about creatures such as spiders but it also invites the public to submit photos and comments as appropriate. The BowerBird website, supported by the ALA, Museum Victoria and the CSIRO, has also served as a public repository for spider photos and general information about spiders, and in about 2013 the QuestaGame project commenced, this encouraging the public to submit spider photos by adding a competitive aspect to the project. And finally, a number of spider enthusiasts have created their own websites, each concentrating on the spiders present in the part of Australia in which they live. The Tasmanian Spiders website launched in 2008 by John Douglas is a good example of this.
THE HISTORY OF AUSTRALIAN SPIDER VENOM/ANTIVENOM RESEARCH
DEVELOPMENT OF THE REDBACK AND FUNNEL-WEB ANTIVENOMS
In Australia the medical authorities keep records of all instances of spider bites that require medical intervention and by 1955 it was generally agreed that the only spiders likely to cause life-threatening envenomation syndromes in humans are the redback spider, Latrodectus hasseltii, and the Sydney funnel-web, Atrax robustus, the funnel-web being the more dangerous of the two. For this reason the Commonwealth Serum Laboratories (CSL), which was founded in 1916 for the production of vaccines but since 1928 had also been developing and supplying snake antivenoms, now started to look at the production of antivenoms for the redback and funnel-web spiders.
People are often bitten by redback spiders because this species likes to build a web and associated retreat in crevices such as the rims of plant pots. Redback venom adversely stimulates the nervous system and induces very strong and intractable pain but some victims still do not seek medical assistance and after a day or two of feeling quite ill recover spontaneously. Saul Weiner was initially in charge of spider antivenom work at CSL and by 1956 CSL was able to announce the production of an antivenom that was effective against redback venom. However, after some research for an effective funnel-web spider Weiner declared his inability to induce production neutralizing antibodies in either horses or mice that had been immunized with male Atrax robustus venom.
The toxin in funnel-web spider venom stimulates the motor nervous system by opening sodium ion channels on the presynaptic side of each nerve synapse (junction) and this causes spontaneous discharge of nerve impulses along the motor nerves. The results of this include repetitive and totally involuntary stimulation of all skeletal muscles (leading to twitching and muscle spasms), disturbance of the normal heartbeat with an initial increase in heart rate and later dysthythmia or even arrhythmia, compromised breathing action, severe pulmonary oedema, and excessive secretion of all exocrine glands. Prior to 1980 no hospital intensive care unit could overcome these effects, though the victim could take up to 5 days to succumb even when given the best care available at that time. Fortunately, funnel-web spiders only bite humans defensively and the majority of bites do not involve injection of enough venom to cause illness in the victim.
In 1966 Struan Sutherland took over running of the antivenom work at CSL and for some years the funnel-web antivenom project was largely put on hold. By 1978 Sutherland had become aware that the blood of such vertebrate animals as lizards, chickens, cats, dogs and mice had detectable amounts of what he called 'natural' antibodies against the funnel-web toxin. Curiously, three years later he was claiming that sera from unimmunized animals have insignificant amounts of neutralizing antibodies, this comment being his response to a media report that the author of this website had announced that he had demonstrated that blood plasma from laboratory rats that had not been exposed to funnel-web venom had proved to be very effective in blocking the in vitro effects of the venom of the the Toowoomba funnel-web species now known as Hadronyche infensa.
The funnel-web venom assay method developed at CSL in the 1970s involved injecting known amounts of male A. robustus venom into newborn mice. These had to be less than a day old because by the second day of their lives they were much less responsive to the toxic effects of the venom. Even the author found that the blood of a very young puppy had much less neutralizing power for funnel-web venom than that of an adult dog. Quite a few people have claimed credit for noting that all vertebrates except humans and other primates have a natural immunity to funnel-web venom but, amazingly, until 1980 no one seemed to have realized that the development of this resistance paralleled the increase in overall immunological competence that happens in vertebrates in the earliest period of their lives. We still don't know the identity of the antigen(s) that induces this 'automatic' immunity to funnel-web venom and neither do we know why only primates miss out on this spontaneous immunization. Struan Sutherland initially offered an alternative explanation for the increasing funnel-web resistance most animals exhibit as they grow older. He thought it is probably due to increased myelination of the nerve fibres within the developing nervous system but he admitted he had not tested this hypothesis, which is now completely discredited. When it was clear the natural immunity is due to the presence of neutralizing antibodies Sutherland described these as non-specific and of no clinical usefulness whatsoever.
Early in 1980 the author of this website tested Hadronyche infensa venom on an isolated nerve-muscle preparation from the cane toad, Bufo marinus, and found that it immediately caused rapid and powerful contractions and fasciculations (twitching) of the toad muscle but these could be completely prevented by premixing the venom with 1.5 mL of rat blood plasma. The blood of pigs, rabbits, horses, dogs, cats, mice, and pigeons also had essentially the same blocking action. In addition, rat plasma could even reverse contractions already caused by H. infensa venom and was equally effective against the venom of Atrax robustus and two other common funnel-web species. Another significant observation was that when H. infensa venom was infused into anaesthetized lab rats a relatively large quantity of venom was needed to elicit signs of envenomation and these slowly faded away unless the dose of venom used was so high the rat died quickly due to cessation of its heart beat.
It should pethpas be mentioned at this point that a very important life-saving technique developed by Struan Sutherland and his colleagues is the application of a pressure immobilisation bandage over a funnel-web spider bite site to slow the rate at which the venom is washed into the circulating blood. This bandage resembles a tourniquet except that it only slows down the blood and lymph flow out of the bite site rather than totally stopping it. This worked so well on monkeys when administered shortly after the venom was injected that even when the bandage was removed a couple of hours later the venom often had little or no adverse effects on the monkeys. Unfortunately, it is of little or no use when the bite site is on a part of the body other than an arm or leg. But does this observation by Struan Sutherland prove that even in primates such as humans and monkeys there is a small amount of neutralizing capacity against funnel-web venom in the circulating blood? Yes, maybe it does.
Suspecting that the reason why rat blood plasma was successful in blocking funnel-web venom is that it contains specific immunoglobulins (antibodies) against the active venom toxin the author next used ammonium sulphate to precipitate the immunoblobulin fraction from a sample of rat plasma. The crude antivenom produced in this way worked just as well on the toad nerve-muscle preparation as whole blood plasma had done. Then in May 1980 at the Prince Henry Hospital in Sydney and with the assistance of a small medical team associated with the University of New South Wales the author tested whole rat plasma and a saline solution of this immunoglobulin precipitate on five anaesthetized macaque monkeys. Partial or complete inhibition of the venom was seen in only three of the five monkeys tested but this marginal success was to be expected because of the uncertainty as to the amount of immunoglobulin preparation needed to effectively oppose the sample of male Atrax robustus venom supplied by CSL.
However, the results of these monkey tests were published in the Medical Journal of Australia and were also sent to Struan Sutherland at CSL. Two months later Sutherland announced to the media that CSL had finally manufactured a working funnel-web antivenom using immunoglobulins separated from the blood of rabbits immunized with male A. robustus venom and purified on a Sepharose A chromatography column to an extent that made the preparation suitable for administration to humans. He did not publicly acknowledge the receipt of the results from the author's team and actually stated that the author's crude rat plasma preparation only contained non-specific 'natural' antibodies and could not be considered as an effective funnel-web antivenom. He also claimed that heating blood plasma to 56 degrees centigrade for 30 minutes completely destroys these natural antibodies but when the author tested this claim he found it was not correct, at least for rat plasma which retained most of its antivenom potency after being preheated.
In 1981 Sutherland was able to successfully test the CSL antivenom preparation on a seriously ill funnel-web victim at the Royal North Shore Hospital in Sydney. What followed was a spirited effort by several other funnel-web researchers (but not the outhor) to claim as much public recognition as possible for the development of the working antivenom but in the end all of the credit has been given to Struan Sutherland, whose method for production of the antivenom is still in use today. There were those who felt that CSL got too much credit for this work and in 1982 the author published a paper in the Australian Journal of Experimental Biology and Medical Science (Vol. 60, pages 191-202) in which he provided experimental proof that the active components of his rat plasma antivenom preparation were IgG, IgA and IgM immunoblobulins, which are the normal antibodies that result from a typical immunization against any kind of foreign antigen. However, while Struan Sutherland might not have deserved all of the praise for creating a working funnel-web antivenom it has to be accepted that his CSL product was the only one that could legally have been administered to a human and Sutherland actually had to obtain special dispensation from the appropriate Health Minister before using it on the first person whose life was saved by it. And since this antivenom became available to all hospitals where it might potentially be needed no one has died from a bite by a funnel-web spider!
STUDIES OF OTHER POTENTIALLY DANGEROUS SPIDERS
Over the last 60 years there have been occasional reports of adverse consequences following bites by a variety of other Australian spider species. The redback spider has been a very common offender but at least one or two members of the theridiid genus Steatoda, which is a close relative of the redback spider, are also quite common in Australia and are claimed to have some ability to harm a human victim, though instances of this are limited in number and not thoroughly proven. Most if not all of the Atrax and Hadronyche species are certainly dangerous to humans, tests by the author showing that the venoms of all of the more common funnel-web species had similar effects on unprotected toad muscles, that of Hadronyche formidabilis appearing to be marginally the most potent. Male spiders were found to produce much less venom than females but it was much more toxic because males do not attempt to feed on reaching adulthood, unlike females. Effects on females of feeding on insects or frequently repeated milkings by the author were found to include decreases in the volume and potency of the venom collected.
Each funnel-web species has now been shown to produce a neurotoxin that is a small peptide molecule unique to that species. Thus A. robustus venom has robustoxin and the Blue Mountains funnel-web Hadronyche versuta has a very similar peptide called versutoxin. Fortunately, the CSL funnel-web antivenom seems to be effective against the toxins in the venoms of all funnel-web species and, surprisingly, it was also shown in laboratory tests to neutralize the toxin of the male Eastern mouse spider Missulena bradleyi, which seems to be almost as dangerous as that of a funnel-web and apparently acts in much the same way. In addition, in February 1985, the CSL funnel-web antivenom was administered on Sutherland's advice to a 19 month old child bitten by a male M. bradleyi spider on a farm near Toowoomba, Queensland. The fact that the antivenom seemed to have caused a rapid improvement in the child's condition is good news in that it means there should be no need to create an antivenom specifically for mouse spider venom.
A researcher who has been greatly involved in the search for clinical evidence of the harmful effects of bites by Australian spiders is Geoff Isbister, presently working at the University of Newcastle. Isbister has evaluated the many media reports that, as described in the next section, white-tailed spiders (Lampona species) can cause serious skin damage when they bite. Isbister has also accumulated medical records about bites by other Australian spiders but perhaps the most comprehensive recent review of the dangers associated with bites by Australian spiders has been a 2015 Springer Science publication by David Wilson (James Cook University, Townsville). Both Isbister and Wilson have concluded that there are no Australian spiders other than the ones mentioned above that have venom proven to be life-threatening to humans.
There have even been a few mostly anecdotal reports that the venoms of barychelids such as Idiommata species and tarantula species like Selenocosmia stirlingi can cause at least moderate harm in human victims although other common mygalomorph spiders, including members of the Idiopidae, Nemesiidae, and Dipluridae, appear to be virtually harmless to humans despite their relatively large size and aggressive behaviour. But what about the many larger Australian araneomorph species? Well, the available evidence at present is that the more common ones that humans often find around their homes include the araneids Eriophora and Nephila, the sparassids Holconia and Heteropoda, and the wolf spider Tasmanicosa godeffroyi and these all have little inclination to bite unless trapped against the skin and only cause very minor adverse effects when they do. On the other hand, spider venoms all contain a mixture of toxic agents and some of these cause temporary inflammation and pain at the bite site and occasionally mild systemic symptoms as well. In this regard the most frequent offenders seem to be the Salticidae, none of which are known to be capable of causing life-threatening syndromes in humans.
THE WHITE-TAILED AND FIDDLE-BACK SPIDER CONTROVERSIES
However, there have been two kinds of araneomorph spiders that have caused flurries of media interest in the recent past because of their alleged danger to humans. The first of these is the white-tailed spider, usually stated to be Lampona cylindrata or Lampona murina, although there are many other Lampona species in this country and these presumably all have similar venom properties. It appears that Struan Sutherland was the person most responsible for the development and propagation of the belief that a bite by a white-tailed spider bite can cause severe and long-lasting skin ulceration in humans. In 1987 he published an article in the Medical Journal of Australia entitled "Watch out, Miss Muffet!" but by 1991 this author had performed and published experimental work on both human and mouse skin that showed that white-tailed spider venom has very little capacity to cause necrotizing arachnidism and that the venoms of golden orb-weaver, huntsman and wolf spiders were all much more potent in this regard despite the fact that no one ever seems to seek or even need medical help following a bite by any of these species. In 2003 Geoff Isbister and museum arachnologist Michael Gray published a paper showing that there have been no clinical reports of significant skin ulceration by white-tailed spider bites. But such was the power of Sutherland's initial comment that even in 2018 many people are still afraid of the white-tailed spider, which has an annoying habit of taking up residence in houses.
The second kind of spider to come to the attention of the media in the last few years is the fiddle-back spider Loxosceles rufescens. This is a close relative of the American sicariid species Loxosceles reclusa, which has a proven record of causing skin ulceration that persists and expands for a long period of time. Loxosceles rufescens probably does have some capacity to do what the equivalent American species does but bitings are almost unknown in Australia because this spider has been found only in a small part of Adelaide and does not seem to be extending its range much. However, for a few years a hoax message did the rounds of Australian email users, who were told this kind of spider is present all over Eastern Australia and is rapidly heading towards Western Australia. This email carried the logo of the Australian Red Cross to give it more ligitimacy and included some images of a human hand displaying severe skin ulceration. However, this was a hoax email and the images were from a biting by Loxosceles reclusa in the USA. Sadly, stories of this kind readily gain the attention of the general public but are very hard to eliminate once they have started to circulate.
SPIDER VENOM INSECTICIDE RESEARCH
There is one other spider venom story that deserves to be mentioned here and it once again started with funnel-web spider venom. Most spiders have insects and other spiders as their normal prey and it was apparent by 1990 that the peptide toxins they have that cause serious harm in humans are not the ones they use to subdue their normal prey. Indeed, the question of why they have agents like robustoxin and versutoxin in their venom at all still remains to be answered. Perhaps it is just for use as a defence against predation by vertebrate animals but if this is the case then it no longer serves that purpose very well because almost all of the vertebrates likely to attack a funnel-web spider now have some degree of immunity to its venom. However, from about 1985 onwards overseas researchers were looking at the chemical nature of insecticidal substances in spider venoms and had already discovered a variety of active agents, notably polyamines but also some peptides, amines and other agents.
It was for these reasons that in 1990 the author collaborated with Professor Merlin Howden (Macquarie University) to obtain some funding from a Federal Government organisation: the Rural Industries Research and Development Corporation (RIRDC), to search for insecticidal toxins in funnel-web venoms. Since both of us had previous research experience involving funnel-web spiders and because the cotton boll worm, Heliothis armigera (now Helicoverpa armigera) was at that time causing serious problems for Queensland and NSW cotton growers, we decided to fractionate samples of H. infensa and the three other common NSW funnel-web species, always using venom from which the peptides that are life-threatening in humans had already been removed. A Sydney private research firm, Deakin Research Limited, assisted in this project by providing some peptide syntheses. The author's involvement in the project was to supply venom for fractionation and also to raise colonies of H. armigera larvae and to inject these with any venom fractions that required testing for insecticidal activity.
Success in this project was achieved very quickly. A Hadronyche infensa venom sample typically could be fractionated into about 22 different peptides only two of which exhibited any toxicity when injected into Heliothis larvae. But these had the remarkable effect of causing the larvae to stop feeding on the special diet provided and to commence a pattern of uncontrolled writhing that continued until they died a few days later without ever maturing into adult moths. In addition, an active fraction of H. infensa venom was injected into living specimens of a range of common insects, including a species of beetle, grasshopper, cockroach, hemipteran bug and dipteran blowfly, and in all cases the toxin proved to cause rapid paralysis and inevitable death. However, the same fraction was harmless when injected into newborn mice as used by CSL in their funnel-web venom assays. Subsequent work revealed the amino acid sequence and molecular folding in each of these peptides, which allowed them to be synthesized. Unlike the sodium ion toxins that cause dangerous and uncontrolled presynaptic nerve stimulation in humans these insecticidal toxins were found to be presynaptic calcium channel blockers and since calcium ions are vital for transmission of nerve impulses across synapses they have the effect of blocking motor nerve pathways rather than stimulating them as funnel-web toxins do. Why they do not have a similar action on calcium ion channels in humans and other vertebrates appears not to be known.
In January 1992 the intellectual property (the information associated with this spider insecticide work) generated by the above project became the basis of a patent owned by two universities, the RIRDC, and Deakin Research Limited, neither Professor Howden nor the author having any rights to the sale or other use of the patent despite having performed the major part of the experimental work. Sadly, the patent eventually lapsed after 17 years without ever being used because at that time insecticide manufacturers were happy with what they were already making. Some initial work was carried out by the author and his co-workers to incorporate the gene for this spider peptide into a virus that is said to attack only H. armigera larvae but financial support for the project could not be obtained, largely because the gene for the toxin of the bacterium Bacillus thuringiensis had already been successfully incorporated into the genome of the cotton plant, making it lethal to any Heliothis larva that tried to feed on it. In some respects this is a more efficient way to protect a crop from attack by an insect pest but there is always a concern that beneficial insects or other animals might unintentionally also be adversely affected by it.
However, with the passing of time other people took this insecticide research further. In a 2006 article in the journal Transgenic Research a Pakistani team led by Sher Afzal Khan announced that they had successfully incorporated the gene for one of the Hadronyche versuta insectidical toxins into the cauliflower mosaic virus and thence into tobacco plants, which now proved lethal to any Heliothis armigera larvae that attacked them. At about the same time Professor Glenn King, working at the Institute for Molecular Bioscience (part of the University of Queensland), also was searching for useful insecticidal toxins in the venoms of funnel-webs and other kinds of spiders. Having a strong entrepreneural instinct, Glenn King in 2005 founded a commercial organisation called Vestaron and eventually moved it to Michigan USA to improve its viability. This company has used genetically modified yeasts to produce large quantities of an insecticidal toxin from H. versuta and near the end of 2017 obtained permission from the US Environmental Protection Agency to market two of their insecticidal products as from the beginning of 2018, but only for use on greenhouse crops. This of course can only be perceived as the start of the development of spider toxins as commercial pesticides and more needs to be done before this kind of insecticide will be approved for broad-acre crops or other purposes. However, since there are so many known spider species and each has at least one unique insecticidal molecule in its venom it could now be a long time before the world runs out of pesticides to which insects have not yet developed resistance.
Email Ron Atkinson for more information. Last updated 5 April 2018.