Oratunga Cactus Cull – 1-8 September 2019

Report 3

A happy group one morning. Probably Thursday as Gini had arrived home late Wednesday, and Les and Eileen and Alan and Cecelia were leaving Friday. From left: Bob, Mal, Gini, Skye, Ralph, Cecilia, Alan, Sue, Greg, Ross, Jim, Betty, Bruce, Syd, Robert, Ruth, Peta, Brian, Dorothea, Eileen, Trevor, Barbara, Tim, Maggie, Katie, Les and Cynthia.

Report of Wheel Cactus treatment at Oratunga

September 2019

Ralph Abbot

Introduction

In June 2011 a group organised via the Overland 4WD Club spent a week treating wheel cactus in Oratunga station on the Glass Gorge Road west of Blinman. Each year since a group has spent a week at Oratunga cacti killing. Statistics for previous years are tabulated below.

Philosophy

For many years larger teams of volunteers have been working on Gum Creek, Alpana and Oratunga stations eliminating cacti. Even if the very last cactus on each of those stations was eliminated they would still be surrounded by properties carrying cacti. So the plan this year was partly to search stations from Lake Torrens to Lake Frome, and from Beltana in the north and the Flinders Ranges National Park in the south in an attempt to locate and eliminate outliers. That would then leave a core with cacti to be treated. This year the search started at the Lake Torrens end, with the flood plain on the western side of the ranges plus the Parachilna Gorge and the creeks that flow through it and out through the Parachilna gap onto the western flood plain.

Diary and results

Friday 30th August 2019

Ralph, Trevor and Barbara and Mal, Cynthia and Syd drove to Oratunga.

Saturday 31st August 2019.

Saturday morning Ralph, Trevor and Barbara and Mal, Cynthia and Syd drove to Eregunda Creek to explore the track to the Eregunda mine, near Trevor’s grandfather’s garden. It was said that the produce from the garden was taken on a track to the mine and then went on the track from the mine to Blinman. On a website there is a track indicated from the Narrina Rd to the mine. The first part of that we followed last year but that took it over a hill and that was a most unlikely path when along the Eregunda Creek would have been much easier.

The path taken this year (blue) went along the creek as far as it crossed the pale white track and followed the pale white track along the foot of the hill.

On the map the pale white track is the one on the website. The red track is along the Narrina road. The white track where it leaves the Narrina road climbs over a hill then down into the Eregunda Creek. Why would loads of ore be taken over the hill when they could more easily taken along the flat creek? The path taken this year (blue) went along the creek as far as it crossed the pale white track and the followed the pale white track along the foot of the hill. Closer to the mine a wide path through the trees opened up and was easily followed all the way to the mine. The hook at the end of the blue track is where the two or more entrances to the mine are. One is on one side of the hill but the major openings are on the other side of the hill. On return the wide path was followed as indicated by the straight section in blue. At the lower end the route of the path on flat terrain became uncertain because of regrowth but the track must go from the end of the straight section to the creek. (Our (blue) track curves around toward where our vehicles were parked. The terrain is flat there and the track could have gone anywhere towards the creek). Ross and Betty arrived later on Saturday and set about erecting the awning on their new camping trailer with lots of helpful advice from those watching!

Sunday 1st September 2019

Everybody else arrived on Sunday. A number of maintenance tasks were undertaken by those already on site.

Monday 2nd September 2019 and Tuesday 3rd September 2019.

Two teams were dispatched to search outside the mountains west of the ranges. Both called in to Mt Falkland Station which is located on the plain just outside the gorge. One team searched north of the road to Parachilna while the other searched south of that road. Les’ team found just two cacti north of the Parachilna Road and then drove north along the Leigh Creek road and saw no evidence of cacti. They then treated a number of cacti in Green Well Creek valley, the first valley inside the western side of the mountains, then on the southern end of Glass Gorge Road.

Trevor’s team treated a number of cacti south of Mt Falkland station along the Parachilna Creek outflow and in the western end of the Parachilna Gorge. The two green waypoints are rope cactus.
Ross’ team on Monday searched the Oratunga Creek gorge north of the junction with the Parachilna Creek.
On Tuesday they searched the same Oratunga Creek gorge south of Kirbin Well and just failed to reach where they finished the day before. The two green waypoints correspond with rope cactus. (The two rope cacti were found at 265927E and 266151E. See Friday’s report).
Brian and Katie’s team searched part of the Heysen trail south of Parachilna Gorge on Monday. The two waypoints at the southern end were where a group of cacti had been treated a year or more before and two living ones were found amongst them and treated
On Tuesday Brian and Katie’s team searched around the Oratunga homestead and across the Glass Gorge Road.

Ralph’s team searched upstream the Oratunga Creek from where it crosses the Moolooloo track. The Oratunga Creek gives access to a large area of land remote from where vehicles have access. Several cacti were treated not far from the start of the walk. At the end of the Monday track the team drove to Moolooloo and spoke with Keith Slade. Several cacti were treated enroute to Moolooloo house.

On Tuesday no cacti were found along the further upstream reaches apart from one cluster of four large Opuntia elata above a cliff. These were not treated but the location (54J 272927E, 6565852N) will be sent to Keith Slade so he can travel on his farm motor bike to the remote location and seed them with cochineal. On the drive home on Tuesday one cactus almost hidden under a bush near Second Spring was treated.

Late on Tuesday Troy Bowman, Shannon Robertson (PIRSA at Waite) and Chris Brodie (SA Herbarium) arrived. Troy and Shannon grow cochineal and cactoblastis at Waite, Chris gathers and presses plant specimens. On Tueday night Troy spoke to the group about cochineal, cactoblastis and boxthorn eradication. Shannon set up a microscope display of live cochineal while Chris demonstrated how he presses plant specimens.

From left, Ralph, Chris, Shannon and Troy

Wednesday 4th September 2019.

Wednesday was set aside as a rest day. A group rode their bikes into Blinman and went on the mine tour. Others drove to Fountain Spring where the cliff was once covered in prickly pear but introduced cochineal has virtually wiped it out. However a large infestation or Devils Rope cactus was found on the southern bank of the Eregunda Creek. Our three visitors collected some cochinealed rope cactus. The group then drove back to where Trevor Burford’s grandfather’s garden plot was located on Eregunda Creek. Enroute a number of rope cactus were seen at the Eregunda crossing with Wirrealpa Road and cochineal was placed on them.

Green waypoints show where the rope cactus were found and treated.

That night the whole group enjoyed dinner in the Blinman Hotel.

Gini arrived home late Wednesday night after a long trip from Berlin via Melbourne for a funeral.

Thursday 5th September 2019

On Thursday Brian and Katie’s group with Syd and Mal travelled north on the Mt Samuel Track, gathered cochinealed pads then spread them around on plants in a valley further north. Two other groups searched lanes both sides of the Mt Samuel track south of Lindow Bore. Nearly all of the area searched was on Alpana’s side of the Oratunga fence.

Friday 6th September 2019

Groups worked in several different areas on the Friday. A number of the group intended to attend the Cactus meeting in the Blinman Hotel starting at 3 pm so teams had been reset so those who wanted to finish in time for the meeting could do so whilst the others went back onto the Mt Samuel Track to continue further south from where the search finished the day before. Trevor led a team into the Parachilna Gorge entrance to treat rope cactus that had been seen previously. Cochineal was spread on those Rope cacti. Then the team drove into the Oratunga Creek Gorge off the Parachilna Gorge. Attempts to drive all the way through it from the south were dented by an impassable section. The team was able to drive in from the northern end and drive nearly as far as the waypoints established on the first day for two rope cacti plants. One of those was found and cochineal placed on it. (Found at 265926E. That plant now has had both poison and cochineal. The other rope cactus at 266151E has only poison).

The green waypoints are the rope cacti.
Brian and Katie’s group searched an area in Glass Gorge Road north of where they searched on Tuesday and found a large infestation of plants.

Saturday 7th September 2019

Several teams combined on
Saturday and went to the infestation that Brian and Katie’s team had worked on the previous day. Another group went to Mt Samuel Track to deal with several left the day before.

Sunday 8th September 2019

On Sunday those still there cleaned up then drove home to Adelaide. Gear was dropped off at Alpana and Gum Creek en route.

Oratunga Score Card 2019

The table below shows the numbers of plants treated each day. Large plants are those treated in location. Small plants are those that are difficult to inject because they are small and soft. They were placed in a bucket and taken back to camp for disposal. Hours are recorded as 7 hours per day per volunteer. That includes travel from Adelaide to Oratunga and return which also averages 7 hours per day. All are listed as
travelling Sep 1 and Sep 8 even though some travelled on other days.

Thanks

Gini and I thank you all for the effort you have put into dealing with cactus and assisting around Oratunga. It has been a great team effort.

Ruth captured the barren scene widely seen during the extreme drought
Dorothea found this isolated patch in Oratunga Creek upstream from Moolooloo.
Note the team leader far below!
Our weeds experts identified these at north end of Blinman North as Opuntia elata (Riverina Pear). Same as those in the photo above. Les photo.