DISTRIBUTION:

Rothschildia arethusa flies in
southeastern Brazil (specimen type locality): probably Rio de Janeiro, Sao Paulo: Barritos (PN) and Cajuru (GO) and Sertaozinho, Santa Catarina, Parana (CM), Minas Gerais (LV); Rio Grande do Sul: Ajuricaba (EBSJ);
Paraguay: Canindeyu, Caaguazu, Guaira, Paraguari, Cordillera, and possibly Alto Parana;
Argentina: Misiones (NV/EB/RF); and
northeastern Uruguay (CP).

Rothschildia arethusa female copyright Kirby Wolfe

Rothschildia arethusa female, Misiones, Argentina,
December 26, 2010, courtesy of Nigel Venters

Rothschildia arethusa female, Dos de Mayo, Missiones, Argentina,
2013, courtesy of Reinhard Foerster.

The arethusa female with the very small forewing hyaline circles (directly above) is likely
1) an aberrant arethusa (first choice);
2) a hybrid between arethusa and speculifer (second choice)—I also note slight indentation in hindwing outer margin opposite pointed end of the hyaline area (more typical of speculifera group) as well as the smaller forewing hyaline areas; or
3) an undescribed species.

The forewing postmedial line is very wavy, especially inwardly concave from the hyaline spot to the costa. Hyaline spots tend to be ovate except in the male forewing where they are more triangular.

While seeking to identify the specimen sent to me by Nigel Venters from Misiones, Argentina, I noticed that all the moths on this page, identified as arethusa, have grey "teeth" surrounding the small black, sharply pointed apical triangle. In the males, there are always two or three such rounded teeth, while in the females, there are usually three to five such teeth. I have not seen any other Rothschildia species from Argentina with this specific character.

Rothschildia arethusa male, Argentina, courtesy of Eric van Schayck.

Rothschildia arethusa female, Argentina, courtesy of Eric van Schayck.

FLIGHT TIMES AND PREFERRED FOOD PLANTS:

Ezequiel Osvaldo Nunez Bustos reports a September flight in Misiones, Argentina. Christopher Prevett reports an October flight in northeastern uruguay. Emily Betania Sloczinski Jerke reports a December flight in Ajuricaba, Rio Grande do Sul, Brazil. April flights in Sao Paulo indicate there are probably at least two broods annually.

Rothschildia arethusa, male, Yacutinga Private Reserve, Misiones, Argentina,
September 13, 2010, courtesy of Ezequiel Osvaldo Nunez Bustos.

Rothschildia arethusa female, northeast of Melo, northeastern Uruguay,
October 27, 2008, courtesy of Christopher Prevett, id by Bill Oehlke.

Larry valentine sends an image from Itanhandu, Minas Gerais, Brazil, taken in early October 2010.

Rothschildia arethusa arethusa male, Itanhandu, Minas Gerais, Brazil,
October 6, 2010, courtesy of Larry Valentine.

Rothschildia arethusa arethusa male, Itanhandu, Minas Gerais, Brazil,
October 6, 2010, courtesy of Larry Valentine.

Rothschildia arethusa arethusa male (verso), Itanhandu, Minas Gerais, Brazil,
October 6, 2010, courtesy of Larry Valentine.

In captivity Ligustrum (privet) is commonly used as a hostplant but lilac, ailanthus and oak also serve well.

ECLOSION, SCENTING AND MATING:

Like most of the Rothschildia, except for the diurnal zacateca, this species calls and pairs at night. Moths often remained paired until the following evening.

Rothschildia arethusa arethusa in copula, Suzanapolis, Sao Paulo, Brazil,
April 1, 2018, Pedro Alvaro Neves

Rothschildia arethusa arethusa in copula, Suzanapolis, Sao Paulo, Brazil,
April 1, 2018, Pedro Alvaro Neves

EGGS, LARVAE, COCOONS AND PUPAE:

Larvae get large and plump and need lots of food. Overcrowding should be avoided. The black colouration distinguishes them from most other Rothschildia species.

It is interesting to watch Rothschildia fashion their cocoons. A strong peduncle with a few support silk strands secures the structure while the larva continues "padding its nest" with a continuous back-and-forth movement of the head. There are both inner and outer cocoons, each with a relatively long valve to facilitate eclosions. Images courtesy of Leroy Simon.

Rothschildia arethusa first and third instars, copyright Kirby Wolfe

Rothschildia arethusa larva copyright Kirby Wolfe

Reinhard Foerster writes from Dos de Mayo, Misiones, Argentina: "In this moment I am breeding Rohtschildias arethusa from Misiones. The adults are different from the Sud (south) of Argentina."

Reinhard has provided images of eggs, several different instars and cocoons, which I have posted to the arethusa file. Below is a fifth instar larva. Hopefully Reinhard will also be able to send images of the adults in a few weeks.

Rothschildia arethusa fifth instar, Dos de Mayo, Misiones, Argentina,
26 days out of egg, courtesy of Reinhard Foerster.

Rothschildia arethusa arethusa fifth instars, Ipeuna, Sao Paulo, Brazil,
courtesy/copyright Pedro Neves.

Larval Food Plants

It is hoped that this alphabetical listing followed by the common name of the foodplant will prove useful. The list is not exhaustive. Experimenting with closely related foodplants is worthwhile.

Ailanthus altissima..... Ligustrum Quercus Syringa vulgaris

Ailanthus Privet Oak Common lilac

Return to Main Saturniidae Index

Return to Rothschildia Index

The pronunciation of scientific names is troublesome for many. The "suggestion" at the top of the page is merely a suggestion.

There are many collectors from different countries whose intonations and accents would be different.

"Rothschildia" is chosen to honour one of the Rothschilds, possibly William.

The species name, arethusa, is from Greek mythology. Arethusa is one of the Nereids who is later turned into a fountain.

Rothschildia arethusa female, Cajuru, Sao Paulo, Brazil,
April 5, 2016, courtesy of Grasiela Oliveira.

Rothschildia arethusa male, Sertaozinho, Sao Paulo, Brazil,
April 7, 2016, courtesy of Josiele Gomes.

Visit Rothschildia arethusa arethusa, additional images.