Friends of the Australian National Botanic Gardens Number 87 December 2017
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Friends of the Australian National Botanic Gardens Number 87 December 2017 Friends of the Australian National Botanic Gardens Patron Her Excellency Lady Cosgrove Vice Patron Mrs Marlena Jeffery President Lesley Jackman Alison Turner Vice President TBA Secretary Jann Ollerenshaw Treasurer Helen Elliot General Committee Wendy Antionak Linda Beveridge Christianna Cobbold Owlet Nightjar, ANBG: a new bird for the ANBG birdlist (see also p 19) Jonette McDonnell David More In this Issue Public Officer TBA Exec.Director ANBG Dr Judy West Post: Friends of ANBG, GPO Box 1777 3 The Myall Gall Midge Canberra ACT 2601 Australia Telephone: (02) 6250 9548 (messages) 4 Friends help char the timber Website: www.friendsanbg.org.au 6 Bush Blitz Friends’ activities and contacts Fronds Committee: Anne Rawson 8 Friends AGM: major projects & related activities Barbara Podger Pam Rooney 9 Life memberships Denis Warne Cathy Robertson 10 Friendly Chatter [email protected] Growing Friends Membership Lesley Harland Pam Cooke Photographic Group [email protected] Schools Photographic Exhibition Growing Friends Kath Holtzapffel Guides Christianna Cobbold Friends Botanical Art Groups Botanic Art Groups Helen Hinton Plant Science Group Photographic Group Brian Moir Plant Science Group Anne Campbell 12 The ANBG Image Collection Social Events Tricia Morton Talks Convenor Doug Laing For all these groups contact: 14 Public Fund Donors [email protected] Booked Walks: 15 What's new in the ANBG Image Collections? [email protected] Fronds is published three times a year. We welcome 16 Gardens Shorts your articles for inclusion in the next issue. Material should be forwarded to the Fronds Committee by 17 Australasian Botanic Gardens Volunteer Guides mid-February for the April issue; mid-June for the Conference August issue; mid-October for the December issue. Email or post material to the Fronds Committee at 18 Friends Briefs the above addresses or, place in the Friends letterbox, located inside the Gardens’ Visitor Centre, between 21 Botanical Bookshop 9.30 am and 4.30 pm, Monday to Sunday. Editorial messages: telephone (02) 6250 9548. 22 What's On, including Thursday Talks Design and layout: Pam Rooney Printing: Union Offset Printers Cover: "Having spent the day at the Botanic Gardens, I was at the car park preparing to leave ISSN 1036 9163 when I saw four Gang Gangs feasting on gumnuts. Taking a photo I noticed a number of sawfly larvae on the branch below. I was then amazed when I realised that two were actually 2 December 2017 Fronds 87 eating the larvae. Some fell to the ground and survived, but the pair didn’t stop till all the larvae were gone. I hadn’t realised that these birds were also carnivorous. An eye opening experience." Alison Milton Another galling story in the gardens: the Myall Gall Midge Roger Farrow fter a Thursday lunchtime and surrounding area. Accordingly, I have others, although I have not recorded talk at the Gardens this April, deposited specimens of the midge with them from aerial samples taken while a friend from ANPS, Helen the Australian National Insect Collection. working on insect migration at CSIRO. Brewer, showed me some galls According to Peter Kolesik, D. glaucula is Our specimens of this Acacia in the infesting three trees of the Myall, Acacia also recorded from a related, non-weeping A gardens would be several hundred pendula, in bay three of the south-west acacia, A. omalophylla or Yarran, that kilometres further east of the nearest car park. They appeared to be a type of occurs in the same areas as A. pendula. wild populations on the western plains flower gall since they occurred on the (west of Wagga). However, A. pendula is I recently checked some flowering peduncles of the axillary flower racemes, widely planted by local Councils in parks Myalls growing along the roadside in rather than on the shoots or leaves. The and along nature strips throughout the the Riverina near Darlington Point but galls varied in colour from fresh pale western slopes and tablelands of New there were no galls present anywhere. It green to dark brown and withered which South Wales. These attractive trees are is interesting to note that the local galls is assumed to be a function of age. I also grown in rural and urban gardens also produced several different species of removed a small bunch of fresh galls and in local botanic gardens in the same parasitic wasp whose larvae would have for research purposes, dissected some areas. David Taylor from the Gardens parasitised the midge larvae. It is possible individual galls, put the rest of the bunch showed me another specimen in the that this gall midge is well controlled by in a jar, and checked the internet. My Mallee section above the car park and this parasitic wasps in the natural range of the conclusion was that they were flower tree was also covered with old Dasineura Myall. galls induced by a gall midge, Dasineura galls. David also told me there were speci- species in the family Cecidomyidae. This Dasineura is an interesting genus of gall mens of A. pendula on the median strip was confirmed when some flies emerged midge because several species have been of Southern Cross Drive at Belconnen, in the jar later on the same day. introduced for the biological control of that I then visited, and one of the three Acacia species in South Africa, by reduc- I sent some pictures of the galls and the specimens examined had small numbers ing seed production. I noted that the flies to Dr Peter Kolesik, a Dasineura of fresh Dasineura galls, although all three A. pendula at ANBG had produced far expert at Adelaide, and he confirmed that trees were heavily infested with the fungal fewer seedpods than normal. All the trees the species was D. glauca and its host is, gall, Uromycladium tepperianum. had also produced new flowers on the you have guessed it, A. pendula. He also It is therefore likely that this gall midge terminal shoots available for the emerging said that it was a new record for the ACT disperses by relatively short flights midges to infest. between scattered populations of natural stands and planted specimens of A. pendula throughout our region. It is also possible that gall-flies migrate in the upper winds like many vagile small insects, including aphids and many Dasyneura larva All photos: Roger Farrow All photos: Dasyneura galls on A. pendula Dasyneura galls on A. pendula Dasyneura glauca Fronds 87 December 2017 3 Friends help char the timber Lachy Brown, Cave Urban ust as fire is an essential agent of two and a half metre-high platform; and known as radial sawing. The blackened regeneration in many Australian a ladder-connected crow’s nest in the poles and boards (whose naturally tree species, so it proved to be an forest canopy. contoured edges complement the important element in the design of layers of paperbark) provide a perfect J The surrounding Melaleucas’ myriad the Gardens’ newly completed Paperbark backdrop to the dappled deep filo-pastry-thin layers of bark not only Treehouse. The Friends played a key greens of the enveloping forest. protect the living trunk against the role in a series of charring days when ravages of fire, they harbour epicormic The majority of building materials came the charring torch was applied to the buds that sprout only after the trunks from recycled sources. The soaring dead structural tree trunks rising through the have received a decent torching. and charred tree trunks are from the platform and holding the crow’s nest; Gardens. The turpentine piers, joists and to the ramp and platform’s weather- This life-giving baptism of fire sparked and decking came from demolitions of board cladding. A BBQ lunch matched the idea of giving the treehouse timbers old wharves. The rosewood handrail and the food with the activity. the same treatment by applying the ladder rungs are 100 year old Central ancient Japanese technique of Shou- Queensland fence posts from the filmset Sydney-based arts collective, Cave Sugi-Ban, literally translated as “burnt of Australia. The whole design and Urban, designed and built the Treehouse cedar board”. for a clearing in a sensitive micro-habitat building process was based on collabora- - a copse of Melaleuca thriving in spring- The charring of timbers serves the tion with the Friends, the ANBG staff, fed boggy ground just below a walking treehouse in important ways beyond the amazing building team and extended track, near the Gardens’ educational the symbolism of fire’s role as destroyer to a cultural exchange with Chilean facilities. and regenerator of life in the Australian sculptor, Carolina Pinto, who came to forest. The carbonised outer layer create the organic steelwork that grows The Treehouse is a ramp-accessible provides a natural weather shield and on and around the trunks of the tree platform, floating out among the papery gives extra protection against fire by columns and allows native vines to grow trunks, bringing unique intimacy to resisting ignition. The boards were cut through the structure and anchor it to the experience of this wild area on three longitudinally as wedges from Victorian the forest floor. levels: the understorey below-decks; a silver ash logs in a revolutionary process Dave Bassett Cave Urban Jim Gould helping with the charring Organic steelwork 4 December 2017 Fronds 87 Lesley Jackman On the very last, and somewhat chilly day deterred some but Jim Gould of the of winter, various Friends assembled on Friends Photographic Group led the the Paperbark Lawn of the Gardens, just Friends’ effort, enthusiastically charring below the site of the Paperbark Treehouse, the trunk of a red box (Eucalyptus to find out about the mysterious Japanese polyanthemos) that has since been hoisted art of yakisugi, or carbonising wood.