Arctornis in Singapore.

After more than a decade there is still no further studies of the Arctornis in Singapore.
MoB remains the sole reference.
The white species are very difficult.
However a few which can be identified can be eliminated from the unidentified list.

Arctornis singaporensis.
White, without corrugated scalings.
No black discal spot.
Veins green tinged.
Male ground whiter & the veins stripes less defined.
Female vein stripes enhanced by interneural bands of white scales,
The two sexes can look like different species.
Males.
https://static.inaturalist.org/photo...706/large.jpeg
https://inaturalist-open-data.s3.ama...3155/large.jpg
https://inaturalist-open-data.s3.ama...586/large.jpeg
Females.
https://inaturalist-open-data.s3.ama...366/large.jpeg
https://inaturalist-open-data.s3.ama...3/original.jpg
Pair.
https://www.inaturalist.org/observations/105780706


Arctornis marginalis.
This rather rare as there is only one shot.Veins tinged green; grey triangles at distal margins.
Apical costa dark edged.
Singapore.
https://www.inaturalist.org/observations/82994882
P. Malaysia. Male & female.
https://www.inaturalist.org/observations/35231033
https://www.inaturalist.org/observations/19966353

Collonette in 1932 wrote onthe Arctornis in Malaya (including Singapore).
The white species recorded in Singapore includes A. nivosa, singaporensis, phrika, riguata, perfecta, camirusquama & marginalis.



A 2019 survey of the Bukit Timah Forest include a new record, A. ungula.
A. ungula is described as " frons with three black spots & two lower ones. legs spotted.
https://www.mothsofborneo.com/part-5...thini_1_40.php
Probable A. ungula.
Sabah.
https://inaturalist-open-data.s3.ama...491/large.jpeg
P. Malaysia.
https://inaturalist-open-data.s3.ama...0195/large.jpg

Three species recorded in the past in Singapore are probably extinct.

1. Arctornis perfecta.
Large species with deep & acute FW in the male.
No discal spot; satiny white without corrugation.
https://www.mothsofborneo.com/part-5...thini_1_36.php
P.Malaysia.
https://static.inaturalist.org/photo...7015/large.jpg



2. Arctornis phrika.
FW with a discal spot & a sinuous postmedial fascia.
Frons & palps dull rufous brown & legs patched the same.
https://www.mothsofborneo.com/part-5...thini_1_26.php
Fortunately there is a BOLD image with visible patterns.
http://v3.boldsystems.org/pics/EPNG/...1479336568.JPG
Sabah.
https://inaturalist-open-data.s3.ama...135/large.jpeg
P. Malaysia.
https://inaturalist-open-data.s3.ama...7577/large.jpg
https://inaturalist-open-data.s3.ama...9/original.jpg
https://inaturalist-open-data.s3.ama...5808/large.jpg

There is much confusion with Arctornis poecilonipha in the past.
The general description seem to fit both.
https://www.mothsofborneo.com/part-5...thini_1_21.php

Arctornis poecilonipha.
FW with a rather larger irregular discal spot.
Frons with a dark brown patch & palps much paler; legs marked with dark brown.
FW more densely laid with opalescent scales, postmedial angled at 90% to costa at upper third.
P. Malaysia.
https://inaturalist-open-data.s3.ama...9230/large.jpg
https://inaturalist-open-data.s3.ama...8089/large.jpg
https://static.inaturalist.org/photo...2218/large.jpg
https://inaturalist-open-data.s3.ama...0203/large.jpg



3. Arctornis camurisquama.
A distinctive white arcuate postmedial band that falls short of costa & dorsum. Costa more reflective.
https://www.mothsofborneo.com/part-5...thini_1_50.php
Sabah.
https://inaturalist-open-data.s3.ama...695/large.jpeg

Following are attempts at ID.
There are far fewer species in Singapore & the majorities are likely to be widespread species.


Arctonis nivosa. Mainland Asia.
This is recorded from Singapore.
Collinette state of this species , diaphanous like A. singaporensis, but creamy white, denser scaling & lacks the green veins.
One specimen match this well.
Bukit Panjang Sep 2020.
https://inaturalist-open-data.s3.ama...494/large.jpeg


Arctornis semihyalina. Sundaland to PNG.
Translucent without dense patches; fine transverse strations in fresh specimen; Frons brown . Palps & foreleg paler brown.Discal spot present.
https://www.mothsofborneo.com/part-5...thini_1_24.php
June 2022 MacRitchie Reservoir.
https://static.inaturalist.org/photo...3592/large.jpg
Jan 2022 Yishan
https://inaturalist-open-data.s3.ama...0115/large.jpg
Aug. 2021 Yio Chu Kang.
https://inaturalist-open-data.s3.ama...3484/large.jpg
Feb. 2020 Yishan.
https://inaturalist-open-data.s3.ama...0728/large.jpg

There are some which do not show much striations although fresh. ? Probable variant.
https://inaturalist-open-data.s3.ama...454/large.jpeg

Wear quickly destroy the patterns in sparsely scaled species.
Worn specimens.
https://inaturalist-open-data.s3.ama...328/large.jpeg
https://inaturalist-open-data.s3.ama...1714/large.jpg
https://inaturalist-open-data.s3.ama...3001/large.jpg
Male with less rounded FW.
https://inaturalist-open-data.s3.ama...429/large.jpeg

Arctornis riguata.

This have a weak discal spot; irregularly oriented scales on the FW.
Diagnostically there are deep faint grey triangle on the distal margin.
The apical costa is darken, causing confusion with A. marginalis.
https://www.mothsofborneo.com/part-5...thini_1_22.php

A serious outbreak occur in Probolinggo Java in 2011.
Initally it was identified as A. submarginata.
The 2013 article indicate it is largely Arctornis riguata.
https://data03.123doks.com/thumbv2/1...-berwarna.webp
https://www.sciencedirect.com/scienc...78301916301024

Dec. 2014 Toh Yi Drive.
https://inaturalist-open-data.s3.ama...5457/large.jpg
Jul.2021 Thomson Lane.
https://inaturalist-open-data.s3.ama...123/large.jpeg
Jun. 2022 Sengkang.
https://inaturalist-open-data.s3.ama...3053/large.jpg

Likely Arctornis rufimarginata.
https://www.mothsofborneo.com/part-5...thini_1_57.php
Wings are uniform white (ie without corrugation or rippled scales).
Fringe & costa golden-brown. Swinhoe states rufous (reddish)
The colour is rendered too grey causing the brown to appear blackish.
Jan. 2019 CWC.
https://inaturalist-open-data.s3.ama...799/large.jpeg


Possibly Arctornis hedleyi.. Prominent FW marginal grey 'triangles'.
https://www.mothsofborneo.com/part-5...thini_1_71.php
Dec. 2021 USR.
https://inaturalist-open-data.s3.ama...542/large.jpeg

Probable Arctornis perfecta.
The only satiny white species here with an acute FW (male) & lack a discal spot.
Uniform white without corrugation or condensed scales.
https://www.mothsofborneo.com/part-5...thini_1_36.php
https://inaturalist-open-data.s3.ama...676/large.jpeg
The 2nd pic shows with a deeper brown patch besides each eye(whitish) & the palps shaded dark brown ventrally.
The brown bar across the base of the antennae is not visible here.
https://inaturalist-open-data.s3.ama...694/large.jpeg

Other similar species have a black discal spot.
UnIDed species.
Fron is marked as described for A. submarginata but wingshape is incorrect.
https://inaturalist-open-data.s3.ama...8487/large.jpg

Probable Arctornis rhopica.
Some resemblance to A. poecilonipha.
Frons , palps rufous brown.
Jan 2020 Mandai Road.
https://inaturalist-open-data.s3.ama.../original.jpeg
https://inaturalist-open-data.s3.ama.../original.jpeg
https://inaturalist-open-data.s3.ama...9024/large.jpg
https://www.mothsofborneo.com/part-5...thini_1_34.php

For comparison. P. Malaysia.
Probable A. rhopica.
https://inaturalist-open-data.s3.ama...4650/large.jpg
A. poecilonipha.
https://static.inaturalist.org/photo...7098/large.jpg

Dear Doctor Seow,

Would then this observation be faded female Arctornis singaporensis?
I do not understand the part where scale structure can be corrugated, but this observation is white, veins are green and lacks a discal spot
Inat link - https://www.inaturalist.org/observations/142270783

Skipping regards
Zicky

Quote:

---

Originally Posted by Zicky

Dear Doctor Seow,

Would then this observation be faded female Arctornis singaporensis?
I do not understand the part where scale structure can be corrugated, but this observation is white, veins are green and lacks a discal spot
Inat link - https://www.inaturalist.org/observations/142270783

Skipping regards
Zicky

---

Yes.
A. singaporensis; No discal spot; no corrugation, green veins ;vein-stripes enhanced in the female.


Corrugation : formings ridges , like roof tiles.
Attachment 28130

Arctornis submarginata.
Widespread species.
Range India to Australia.
A minor pest on tea in NE India. Also feed on Cinnamomum species.
Female. reared from oak. India.
https://www.researchgate.net/profile...richophora.png

One observation matches Holloway's description well.
The frons have a band across the bases of the antennae & across the eyes, the two bands merging; palps ochreous shaded at the tip.
Feb 2917 Pasir Ris.
https://static.inaturalist.org/photos/6209209/large.jpg
FW with a discal black dot, & lightly corrugated scalings.
FW costa lightly edged ochreous & fringes light grey.
https://www.mothsofborneo.com/part-5...thini_1_46.php

From this the following observations can be included
Oct. 2020 Yio Chu Kang.Female (rounded FWs).
The triangular piece is part of the frons between the eyes.
https://inaturalist-open-data.s3.ama...4449/large.jpg
https://inaturalist-open-data.s3.ama...4454/large.jpg

Aug 2020 Woodlands Male.
https://inaturalist-open-data.s3.ama...734/large.jpeg
https://inaturalist-open-data.s3.ama...637/large.jpeg
https://inaturalist-open-data.s3.ama...739/large.jpeg

Aug 2014. Botanic Garden. Female.
https://inaturalist-open-data.s3.ama...3905/large.jpg
https://inaturalist-open-data.s3.ama...3904/large.jpg

Arctornis hipparia.


This is an enigmatic species in as much as the type location is Singapore.
Holloway states the following features.
1. Satiny white with reflective scales coarse.
2. Fringes narrowly brownish ( Most Arctornis have the fringes grey).
3. Frons reddish & palps tipped ochreous.
4. Legs only faintly spotted.
https://www.mothsofborneo.com/part-5...thini_1_73.php


Only one observation comes close.
Probable A. hipparia. Aug. 2018. Mulu N.P. Sarawak. It helps that some of Holloway's specimens also came from Mulu.
https://inaturalist-open-data.s3.ama...6620/large.jpg

Added. This looks correct; Note coarse corrugations, brownish fringes & legs faintly spotted.
Aug. 2021 Bukit Panjang.
https://static.inaturalist.org/photo...4890/large.jpg

Dear Doctor Seow

I shot the following Arctornis at bukit batok today. It has a discal spot, but the antenna,palps and frons are quite well hidden. I cant really decide if it has corrgated marks base on your comments, but i think its Arctornis riguata. I would like to hear your inputs.

Inat link - https://www.inaturalist.org/observations/146109518

Skipping regards
Zicky

Post 13.
Unknown species.
There are many which can not be identified.

TL Seow; Cheers.

Dear Doctor Seow,

Using your ID features, would the following observation be Actornis hipparia? This is shot by user Kleared on inaturalist
inat link - https://www.inaturalist.org/observations/148450319

This mating pair have wing fringes narrowly brownish and their legs seems to be faintly spotted, which is why i ID it as such, but i would like to hear your opinion on this observation

Secondly, is this following observation actornis rutila? Seems distinct with the yellow and brown patches overall
inat link - https://www.inaturalist.org/observations/147696761

Skipping regards
Zicky

Post 15.
Just too difficult.
The wings have strong grey triangles on the dustal margins not seen in A. hipparia.
A. rhopica appear to be the nearest.
https://www.mothsofborneo.com/part-5...thini_1_34.php
Probable A. poecilonipha for comparison.
https://inaturalist-open-data.s3.ama...8089/large.jpg


The 2nd should be correct as A. rutila.



TL Seow: Cheers.

No worries Doctor Seow! thanks for the attempt and understanding