Perga sp. (genus)

Sawfly or Spitfire at Richardson, ACT

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Identification history

Perginae sp. (subfamily)	10 Sep 2024	NKingsford
Perga sp. (genus)	31 Jul 2024	MichaelMulvaney
Pergidae sp. (family)	30 Jul 2024	CarbonAI
Perga affinis	30 Jul 2024	RomanSoroka

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7 comments

NKingsford wrote:

10 Sep 2024

The furthest you can get with this is Perginae. This is one of the Myrtaceae feeding genera which includes Acanthoperga, Antiperga, Paraperga, Perga, Peragrapta, Pseudoperga and Xyloperga.

As there is are no systematic references or diagnostic characteristics of the larvae and with over 50 species within this grouping, it's almost impossible to determine the species, let alone genera in which they belong to.

MichaelBedingfield wrote:

11 Sep 2024

Thanks Nathaniel. And cc @MichaelMulvaney ... If what you say is true then we need to review all the Perga sp. (genus) sightings, which include many larva, see:- Perga sp. (genus)

MichaelMulvaney wrote:

11 Sep 2024

@samreid007 what are your views on this?

samreid007 wrote:

11 Sep 2024

Hi @MichaelMulvaney, sawfly large in Perginae are definitely hard to get to species / genus as there are very few peer reviewed studies that have looked at them. As such, lot's of the information out there is anecdotal. However, that said, there are a few things that would make me lean towards Perga for this sighting (probably affinis or dorsalis).

1. Based on some searches a few years ago, the Perginae that are most commonly recorded in the ACT and nearby are Perga affinis, Perga dorsalis, Pergagrapta polita, Pergagrapta spinolae, Pseudoperga guerinii, and Pseudoperga lewisii. Fewer records exist for Cerealces scutellata, Xyloperga forsiusi, Pergagrapta latreilliid, Pergagrapta turneri, Pseudoperga ferruginea.

2. The record is from July, and the larvae are mid to late instar - this would fit with Perga affinis as the larval stages occur over autumn and winter. It could also fit with Perga dorsalis, as it can be found as larvae all year (however, the late instar stages are more often in spring and summer). I think most other Pergagrapta and Pseudoperga that occur around here are generally late instar in spring, summer, and early autumn.

3. The colour of the body, prolegs, and uropod (tail) is right or Perga affinis or dorsalis, as are the robust short and white bristles (hairs). As far as I know, the other common Perginae around here don't look like that.

Based on the above, I'd say Perga affinis or dorsalis. However, @NKingsford makes some very good points. It would be great to have an entomologist look through our sawfly larvae records and identify any issues. I wouldn't be surprised if they recommended ID-ing to only genus or subfamily.

MichaelMulvaney wrote:

12 Sep 2024

Thanks Sam
I think we will leave the black larvae with white hairs as Perga and I will check that others are ID to Perginae

Cheers Michael Mulvaney

samreid007 wrote:

12 Sep 2024

Let me know @MichaelMulvaney if you want me to have a pass through all the sawfly larvae ID's and classify them on a more conservative basis (e.g. Perga affinis and dorsalis go to Perga sp., other ones go to subfamily, etc). And sorry I haven't been doing much identification work lately! I'll try and get back into it.

HelenCross wrote:

12 Sep 2024

Thanks for the interesting discussion about sawfly larvae!

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