Cicadas, Christmas Beetles and Birds

It has been a summer dominated by cicadas and Christmas Beetles and the local eucalypts and corymbias are showing signs of stress.  Some trees have had most of their leaves consumed by beetles, mostly Christmas Beetles of the genus Anoplognathus, and some smaller trees such as the Red Ash and Creek Sandpaper Fig have been attacked by small beetles known as 'Jumping Beetles'. Christmas Beetles can cause much damage as their natural numbers can be exceeded in areas where forests have been cleared or partly cleared and lawns or grass paddocks have taken their place.  The larvae are the greyish curl grubs that feed on grass roots.  Because there is a greater supply of grass roots than was normal in the past more larvae survive and become adult beetles.  The unnaturally high numbers of adult beetles grazing on eucalypt leaves can strip trees bare.  The New England Dieback that has occurred on the NSW northern tablelands is thought to be due a number of impacts, but consumption of leaves by the beetles is a major cause.





Christmas Beetle Anoplognathus sp. 

 

Christmas Beetle Anoplognathus sp.

Black Nail Beetle Repsimus manicatus



'Christmas Beetle'

                                     

                                          Jumping Beetles on Creek Sandpaper Fig
                                                                   Coutts Crossing




Up until a few days ago the incessant call of ciacdas was all pervading, even into the evening.  A number of species occur locally including the Yellow Monday Cyclochila australasiae ,  Razor Grinder Henicopsaltria eydouxii, Psaltoda pictibasis and others that I am having identified at present.  P. pictibasis is found east of the Great Dividing Range and in NSW there are records from only Tabulum, Iluka and Port Macquarie.  The latter locality requires confirmation.  So my record at Coutts Crossing is a new locality for the species. Cicadas emerge from the soil during the summer after spending years underground feeding on the sap from plant roots.  The larvae climb up onto tree trunks and other objects, and shed their nymphal cases (exuviae).  A small post at the edge of our driveway has a cluster of nymphal cases at the top. Once fully emerged and the wings open and dry out they fly to a tree to feed and breed.  

 

 

 

 

 

 

 

Psaltoda sp. cicada emerging from Nymphal case Coutts Crsossing

 

 

 

Cicada nymphal cases on stump Coutts Crossing

 

 

 

   Yellow Monday Cyclochila australasiae and

nymphal cases Ebor Falls

 

 

Cicada Psaltoda pictibasis Coutts Crossing 

 

 

Razor Grinder Henicopsaltria eydouxii  Orara River Coutts Crossing

 

                               Floury Baker Aleeta curvicosta Coutts Crossing

                       Double Drummer Thopha saccata Nymboi-Binderay National Park


Identifications provided so far have been by Ian Buddle, Max Moulds, Frank Pierce and Lindsay Popple .


For the past few mornings cicadas haven't dominated the sounds of the bush as they have been doing for some time.  The cooler weather seems to have quietened them down and the fact that they provide a rich source of food for many bird species means that their numbers may be dwindling due to predation.  For the past few mornings, the chattering of Spangled Drongos and the calls of Noisy Friarbirds, Little Friarbirds, Noisy Miners, Blue-faced Honeyeaters and Little Wattlebirds have dominated.  Large numbers of these birds have been feasting on the beetles and cicadas.  At least 10 Spangled Drongos, including dependent young being fed by adults, were present but as they are very active this estimate is probably understating the real number present.  A flock of 13 Blue-faced Honeyeaters and a number Noisy Friarbirds, including an adult feeding a juvenile, were also present.
A family of Pacific Bazas, an adult and juvenile Olive-backed Orioles and a couple of Dollarbirds have also joined in the feast.