Rhodogastria ID help

There are only two Rhodogastria species - R. amasis and R. similis.

They are pretty difficult to tell apart, especially as adults.

The caterpillars are quite different in later instars and this is what they look like:

Photos © @leejones and @suncana

The adults are more iffy:

Photos © @gawie @kooscl and @alexlamoreaux @riana60

I copy @beetledude 's notes here from https://www.inaturalist.org/observations/10915652 with updated links:

Telling apart the two Tricoloured Tiger Moths

Rhodogastria amasis

• The two lines on the thorax brown, not orange.
• Hindwing mostly white, or frequently with a peachy wash.
• Distribution: the Cape provinces.

Rhodogastria similis

• The two lines on thorax orange, not brown.
• Hindwing mostly orange.
• Distribution: 'further north'.

Caution:

• In comments on at least two observations, the facts about the colour of the thoracic lines have been reversed.
• In some moths it is difficult to decide whether the thoracic lines are orange or brown. If that is the case, err to the side of brown, except for specimens from KZN and further north.
• There are just two species of Rhodogastria in existence, namely the two above.

MAIN SOURCES:

• Moth expert Hermann Staude at https://www.inaturalist.org/identifications/23985427
• VÁRI, L., KROON, D.M. & KRÜGER, M. 2002. Classification and Checklist of the Species of Lepidoptera Recorded in Southern Africa. Published by the second author, Sasolburg, South Africa, and Simple Solutions, Chatswood, Australia, xxi + 385 pp.

Posted on January 30, 2019 02:28 PM by karoopixie