During the week 20 to 27 August, the Friends of Lord Howe Island and the Museum hosted a Citizen Science beetle week, with Dr Chris Reid from the Australian Museum as guest scientist.
Beetles are one of the key indicators of changes in an island ecosystem; and there are 530 species on Lord Howe Island. They constitute the largest single group of invertebrates on the island.
Citizen scientists undertake first monitoring since eradication of rats
Rodents have been on Lord Howe Island for over a century, and many of the larger beetles were severely impacted, having not been seen since before the arrival of rats in 1918.
Chris Reid and Dr Ian Hutton, curator of the Lord Howe Island Museum, have previously carried out surveys of beetles on the island, before the eradication of rats in 2019. This Citizen Science week survey is the first time the beetles have been monitored since that time.
It was hoped that many beetles would show an increase in numbers following the removal of rats.
Beetle numbers seem to be increasing
Day time and night time excursions were done with volunteers to search for beetles and record any changes in numbers that were observed.
Initial indications are that there have been some quite big increases in the numbers of many beetle species.
Of particular note is the large black flightless beetle Xylotoles wollastoni. During the survey week every night in the forest this beetle was seen. Dr Reid had not actually seen one in his twenty year’s of surveys on the island, and the Australian Museum only has two specimens.
Another rare endemic weevil, known only from three specimens at the Australian Museum is Aethreus cicatricosus.
The two brown Dematochroma picea leaf beetles (shown mating in the photo below) are endemic to Lord Howe Island.
Many other beetles were also in bigger numbers. A full report will be prepared and published as soon as possible.
Beetles of Lord Howe Island
The Australian Museum Lord Howe Island Expedition 2017 – Coleoptera, Chris A. M. Reid; Josh Jenkins Shaw; Arn R. Jensen, 2018, Australian Museum
Citizen Scientists and rare beetles: a win-win for everybody, Chris Reid, 2018, Australian Museum
The citizen scientist survey of large Coleoptera on Lord Howe Island, August 2019, Chris A. M. Reid, Ian Hutton, Saxxon Thompson 2020, Australian Museum