Imperial Hairstreak (Common Imperial Blue) Jalmenus evagoras Wingspan: 32 mm - 37 mm Sighted: October to May
Larval Food Plants: Acacia - A. melanoxylon here
Mating Imperial Hairstreaks
Our regeneration paddock is perfect habitat for the Imperial Hairstreak butterflies where some of the trees are still quite small. It seems they prefer to lay their eggs in batches on young wattle trees up to about two metres high.
Early one evening Trev saw twenty-four newly hatched butterflies grouped together roosting on a small acacia tree.
These butterflies generally fly around the paddock area, occasionally visiting nectar flowers in the garden.
Common Imperial Blue on yellow daisy
Jan 2018, 8.30 am
Claire Cottage Dorrigo Plateau, Jan 2019, 2.34 pm
This female was searching for a suitable crevice to lay eggs. Claire Cottage Dorrigo, Jan 2019, 2.55 pm
She walked over all the branches and up and down the trunk with abdomen lowered. We watched for 20 mins. She was still searching when we left.
In January 2016 we watched a female laying eggs in a crevice of an Acacia branch (see pictures below). We were interested to note that there were no ants on the tree at that time. The following day a few ants were moving about the tree. None were showing interest in the batch of eggs.
Female laying eggs an 24/01/16 in Acacia branch crevice - no ants present on tree
Cluster of eggs laid on 24/01/16 in Acacia branch crevice - difficult to see with naked eye
Eggs on 24/01/16 greatly magnified showing their amazing shape - not visible with the naked eye
Same eggs on 12/02/16 - many appear to have openings - if they have hatched there are no larvae visible. Has a predator attacked the eggs? Ants are present on the tree but not attending the eggs.
Larva with attendant ants
A larvae with this many ants is easy to see
The caterpillars are attended by black ants that protect them from birds and parasitic wasps. In return the ants 'milk' the caterpillars for a honey dew like substance. They often appear as black lumps in the trees as the ants can completely cover the caterpillars and pupae as in the pictures below.
A cluster of larvae
Cluster of larvae and resultant bare branches, Claire Cottage Dorrigo Plateau, 31 Jan 2018
Eggs laid on a branch rather than in a crevice of a sapling, Claire Cottage Dorrigo, 22 Jan 2020
Pupae with attendant ants
Eggs laid in a sapling in photo below left, Claire Cottage Dorrigo, 22 Jan 2020
Another batch of eggs, Claire Cottage Dorrigo, 22 Jan 2020
First sighting summer 2018 of larva - November 5th - First sighting summer 2018 of an adult - November 18th First sighting summer 2019 of larva - November 13th - First sighting summer 2019 of an adult - November 13th
Last sighting autumn 2019 of larva - - Last sighting autumn 2019 of an adult - 11/05/19