A Grave Situation for Key’s Matchstick Grasshopper?

People usually go to cemeteries to visit the dead, but last month we visited 25 cemeteries in Victoria, NSW and the ACT in the hope of finding living specimens of an insect that was once one of the most abundant animals in south-eastern Australia. Specifically, we were looking for a little wingless daisy-eating insect called Key’s Matchstick Grasshopper that is presently under consideration for listing nationally as an endangered animal.

Last year this species was listed as being threatened for the first time in Victoria and this year Zoos Victoria made it one of their ‘Fighting Extinction’ priority species to help support its conservation and recovery. The grasshopper was described from ~30 cemeteries throughout its range in the 1950s and 1960s, which remained one of the last strongholds of this species because the cemeteries provided tiny patches of remnant native grassland that had been protected from grazing. Unfortunately, our recent survey only found Key’s Matchstick Grasshopper at 2 of the 25 cemeteries we examined where it had formerly been recorded, and we also found that the grassland habitat in most cemeteries had been destroyed by mowing.

However, we did find this species in a few small patches of remnant vegetation in NSW and ACT. Moreover, we were particularly excited to find it in one small isolated area near Omeo in Victoria. This is the first record of the grasshopper from Victoria in the last 50 years, and opens up the opportunity for its resurrection in that state.

The grasshopper

Key’s Matchstick Grasshopper goes by the scientific name Keyacris scurra. The genus name of the species and its common name honour the South African-born Australian scientist Ken Key, who spent his professional life studying Australian grasshoppers. Key’s Matchstick Grasshopper was made world-famous as a result of evolutionary studies carried out in the 1950s and 1960s by the geneticist Michael White. White showed that different colonies of Key’s Matchstick Grasshopper varied dramatically in both the number chromosomes (bundles of DNA) they had and in the way some chromosomes were assembled. He collaborated with the eminent US scientist Richard Lewontin on this grasshopper to produce text-book examples of the evolutionary process operating at the DNA level.

White and Lewontin focused their work on cemetery populations because these remained one of the few habitats where Keyacris scurra still occurred. White noted back in 1956 that the grasshoppers were “far more widespread before settlement by the white man”, but that they had been “largely eliminated or greatly altered by close sheep grazing for over 100 years”. He regarded the remaining cemetery populations he was studying as “minute ecological islands”, providing areas of “one to several acres which have been fenced for many years to exclude grazing animals, and hence retain much of the native vegetation that has largely disappeared from the heavily grazed land outside”. However White and Ken Key also documented the loss of the grasshoppers from cemeteries within the former range of the species, noting that of 64 cemeteries surveyed within the former range of the species, grasshoppers were only recovered in 26 of them, with many of the other cemeteries having been “cleared, cultivated and burned-over”.

Both White and Key continued to survey the distribution of the grasshopper extensively in the 1950s and 1960s, leaving behind detailed field notes and scientific papers as well as specimens in the Australian National Insect Collection (ANIC). These notes formed the basis of our resurvey this year.

The hunt

On the 25^th August this year, we set off to resurvey as many of the old Key’s Matchstick sites as possible and also try to identify new sites where the species might have persisted. Late winter is a good time to search for Keyacris scurra, which have an unusual life cycle for a grasshopper. While most grasshopper are abundant in summer, Keyacris scurra hatches in mid-summer and does not quite reach maturity by the end of autumn. The species slowly develops across winter and then mates in the early spring before laying eggs, finally dying off in late spring. To find this species, you walk slowly through suitable habitat during the warmer time of the day (at temperatures above about 10 °C), and look for jumping hoppers around your feet as you disturb their favourite food plants – especially everlasting daisies (Chrysocephalum) and sheep’s burr (Acaena). You then capture them with a device called a ‘pooter’ – a glass cylinder into which you can suck insects via a tube. This makes for an odd sight for the general public, especially in cemeteries, where it no doubt appears that we are hunting elusive spirits!

Victoria, attempt number one

We started our survey in Victoria in the small town of Merton, where Key’s Matchstick Grasshoppers had last been seen in the Merton cemetery by Ken Key back in May 1956. At the time, Key reported in his field notes that the cemetery had dense kangaroo grass (Themeda). But now, as is the case with so many cemeteries we surveyed, the kangaroo grass had been replaced by non-native pasture plants and weeds. Unsurprisingly, no grasshoppers remained, which also proved to be the case in cemeteries in Benalla, Beechworth and Wodonga – all sites where the species had been recorded in the past. We also surveyed a cemetery at Gobur, near Merton, which had some kangaroo grass but no grasshoppers, and also failed to find the species at four new sites in Victoria that we surveyed, even though all of these had suitable remnant vegetation.

The road to Gundagai

The next day we headed up the Hume to the Gundagai cemetery where one of us had previously (in 2018) found a single female in a small remaining patch of kangaroo grass. Unfortunately, much of the site had now been invaded by weeds, and in this survey we failed to find any Key’s Matchstick Grasshoppers. Michael White found that the Keyacris scurra population at Gundagai is genetically distinct from the southern and eastern populations in having an extra chromosome, so we were particularly disappointed to miss this population. In the Gundagai population, the males have 17 instead of 15 chromosomes, with one of the large chromosome pairs having been broken in two.

We were luckier at a small nearby cemetery in South Gundagai. At the back of the cemetery there was a small reserve of less than a hectare of Grassy White Box Woodland that had been fenced off from grazing. Within this area we found a small patch of one of Key’s Matchstick’s favourite foods, the everlasting daisy (genus Chrysocephalum). Within 20 minutes, we had seen 13 grasshoppers! This is a site clearly in need of careful management given the small size of the remnant fragment and restricted location of the remaining Keyacris scurra.

Heading to Cootamundra

For the remainder of the day we searched cemeteries and other sites around Cootamundra, a town known in part for a native wattle tree that has spread around the world and is now classed as a weed. The Cootamundra, Young, Wombat, Murringo and Boorowa cemeteries were all sites where Key’s Matchstick Grasshoppers had previously been recorded. But the species has now been lost from these sites, along with most of the native vegetation. Wombat cemetery, which is only about half a hectare in size, was previously estimated in the 50s to have had a very high density of grasshoppers (totalling around 10,000 animals) but they are now all gone.

However, our spirits lifted when we managed to find two new populations of the species, one along a railway line at Wallendbeen and another in a nature reserve in Boorowa. The Wallendbeen population appeared to be feeding on Sheep’s Burr (Acaena echinata) rather than daisies. This region is thought to contain the 17-chromosome lineage, and is located in the drier, hotter parts of the species’ range.  We were very excited to find extant populations of this lineage because it may harbour genes that will help the species cope with hotter and drier conditions expected under current and future climate change.

Drought and Kangaroos in Canberra

Days three and four of our trip focused on the Australian Capital Territory (ACT) around the nation’s capital, Canberra. The current drought was showing its effects here in the form of severe overgrazing by kangaroos around the town. Canberra is currently also the ‘roadkill capital of Australia’, with many kangaroos being hit as they are attracted to suburban areas during the drought where there is greener food. We visited a property in the suburb of Wamboin 16 km out of Canberra – a bush block with some high-quality Kangaroo Grass habitat and a healthy population of Key’s Matchstick Grasshoppers. Two years ago, a decision was made to fence the property to exclude kangaroos because they were grazing the grass right down to the ground. Even though the grasshoppers might be able to tolerate the direct effects of the drought, they are very vulnerable to the indirect effect of overgrazing, as we failed to find them in any of the overgrazed sites. In addition to this bush block, we were able to locate Key’s Matchstick Grasshoppers hanging on in bushland around Kambah Pool, and at Gibraltar Rocks in Tidbinbilla Nature Reserve – places where they were found in a 1995 resurvey of the Canberra area for this species. The Gibraltar Rocks population area had been badly burned during the firestorm of January 2003, so it was comforting to see the species persisting despite an intense fire.

Classic study sites (almost) all dead and buried

Key’s Matchstick Grasshoppers have provided a unique opportunity to see evolution in action in the 1950s and 1960s. And, of course, any new samples from the same sites now, over 60 years later, provide a valuable opportunity to investigate evolutionary changes over a much longer period of time.   The site studied in the greatest detail in the 50s and 60s was Murrumbateman Cemetery, where Michael White gathered data on chromosomal changes for 11 consecutive years (1955 to 1966). We have surveyed this site now on three occasions. Unfortunately, despite a small amount of suitable habitat remaining, Keyacris scurra appears to be extinct at Murrumbateman. Many of the other old sites studied by White have suffered the same fate, including cemeteries at Wombat, Young and Cootamundra as mentioned as well as Michelago, Bredbo, Bowning, Goulburn, Yass, and Collector to name a few. But we did find a healthy population at the Hall Cemetery in the ACT and a tiny population at the Windellama Cemetery in NSW surviving in a 0.15 hectare patch of tall kangaroo grass. The Windellama site is especially valuable scientifically because White released a population from Murringo which had very different chromosomes from those present in the resident population. White hoped to see if the Murringo chromosomes could become established but noted in one of his scientific papers that when he returned to the site the next year “the area where most of the Murringo males had been released had been ploughed up, leading to changes in the vegetation … It is recorded here in case any descendants of the Murringo males are found in future years”. Perhaps if we can resurrect this population, we can find the answer!

 Rediscovery in Victoria

 On our return trip to Melbourne, we decided to have one more attempt at finding Key’s Matchstick Grasshopper in Victoria. Buried in Ken Key’s field notes are six records of the species from around the small town of Omeo. This site is quite isolated from all the other populations of the grasshopper, being nestled within forested mountains. As we drove into Omeo from the north, we spotted a patch of kangaroo grass and everlasting daisies on the side of the road in some dry, open forest. Within a minute of searching we’d found Keyacris scurra! In fact, we counted over 5 grasshoppers per square meter in some patches, and the habitat extended over about a hectare. We checked the six sites where Ken Key found them in 1966 and 1967, but we found the grasshopper at only one of these. Nevertheless, we did manage to locate two more new areas where the species was present. So, our trip ended on some very good news for the conservation of this species, although the species has been lost from sites where it had occurred even in this remote area.

The future

 Key’s Matchstick Grasshopper has suffered an extreme range contraction over the past two centuries. The total area of native grasslands that it inhabited had already contracted dramatically at the time White and Key were studying its distribution. Our survey indicates that it has since disappeared from the majority of White and Key’s original sites. But it also shows that it isn’t as grave a situation as it could be; the species is clinging on throughout its former range in tiny little patches as small as 0.15 hectares. We also found that a large population still lives on Memorial Hill in Goulburn, while Omeo in Victoria may also turn out to be a stronghold for the species. The Tidbinbilla population is already in a protected area and could benefit from targeted management by ACT Parks and Conservation. The population at Bredbo Cemetery south of Canberra is now extinct but it may occur in the nearby Bush Heritage Scottsdale Reserve. Because of White’s chromosome work, we have an unusually detailed understanding of the genetic diversity of this species, and our field survey suggests that the main genetic lineages persist. Genetic diversity is the key to coping with future environmental change, so we are at a critical point in time for restoring the species in a manner that gives it the best chance for the future.

The solutions to conserving this species and its diversity are likely to be simple. In places where they still occur, we need to ensure that they are protected from overgrazing, mowing, pesticide applications and inappropriate fire regimes. Being an over-wintering species, fire management is especially important because control burns in autumn and winter could have serious effects. Captive breeding can also be used to bolster sensitive populations, and at present we are raising over 100 babies from the Hall Cemetery. Where the grasshoppers no longer occur but the vegetation is still present, fencing off areas so that they can recover from grazing should restore the habitat.  Grasshoppers can then be translocated into these areas using the most genetically suitable race. We found that many cemeteries still have kangaroo grass and native daisies, so there is great capacity for local communities to work together to resurrect these populations (even past community members can contribute by pushing up the daisies!). And in the most extreme case where the habitat has been destroyed, we may be able to reconstruct their habitat from scratch. There will almost certainly be many flow-on benefits from the restoration of Key’s Matchstick Grasshoppers. This species is a very abundant food source for other animals including birds and lizards, especially in the winter and early spring when few other insects are about. We therefore expect to see an increase in biodiversity generally when the grasshoppers are restored.

For all these reasons we think that the resurrection of Key’s Matchstick Grasshopper could become one of Australia’s greatest conservation success stories, as long as we act now before the remaining remnants are lost.

Acknowledgements

Our work is being funded by an Australian Research Council grant to develop conservation strategies for insects.

Written by Michael Kearney and Ary Hoffmann