Syssphinx bidens male, Ecuador, courtesy of Leroy Simon,
I am not sure id is correct on this specimen (WO).
(I think it is more likely Syssphinx centrimacula).

DISTRIBUTION:

Syssphinx bidens moth (wingspan: males: 72-93mm; females: 98-111mm) flies at high elevation in
Venezuela: Distrito Federal, Aragua, Merida; (probably true bidens in Merida and nearby states);
western Ecuador: Esmeraldas (HK), Pichincha (ESs) (probably centrichuchuviana);
northeastern Ecuador Napo; Succumbios?; Tungurahua, Morona-Santiago, and probably Pastaza (probably Syssphinx centrimacula);
southeastern Ecuador: Zamora (probably Syssphinx centrizamorana);
and Peru: Huanuco and San Martin, and maybe Amazonas (probably Syssphinx bidentalis).

Based on DNA barcoding analysis, 2017, many of the specimens previously thought to be S. bidens from Ecuador, are now assigned to the following species: Syssphinx centrimacula from Napo and Sucumbios and possibly other eastern provinces; Syssphinx centrizamorana from Zamora-Chinchipe; Syssphinx centrichuchuviana from western Ecuador: Esmeraldas and Pichincha. Another very similar series of species has been named from Colombia. I think true bidens may be limited to Venezuela, in and around Merida. Another very similar new species, Syssphinx bezverkhovi flies in Venezuela: Carabobo: Rancho Grande El Limon, a bit further east of bidens.

I think the lower specimen in the Bernard Wenczel image is not bidens (for sure), and I think we probably have an image set of two or three different species on this page. Without precise locations, it is also impossible to do id work nowadays.

The Horst Kaech image (below) from Esmeraldas is almost certainly Syssphinx centrichuchuviana, and I have a strong suspicion that the Leroy Simon image is probably from eastern Ecuador where specimens are more likely to be Syssphinx centrimacula.

I will see if Uwe Kaus knows the source location for his images (pretty sure from Esmeraldas, (making all of Uwe images Syssphinx centrichuchuviana). Uwe's larva does look different from the one sent by Kirby Wolfe. i do not know if Kirby's images are from Venezuela (true bidens) or from one of the other countries: Ecuador or Peru.

It is probably Syssphinx bidentalis that replaces bidens in the Peruvian departments mentioned. All of the species mentioned in red are extremely similar and probably can't be determined without DNA barcoding. I have not read, however, that any of them are sympatric, so location offers a very useful clue as to a better guess id.

This species can be very hard to distinguish from other members of the bidens-ocellata-jasonoides group:

Syssphinx bidens, Venezuela: Merida,
Syssphinx bidentalis, Peru: Amazonas; Huanuco; Pasco;, Junin, 1100-2000m.
Syssphinx centrimacula, northeastern Ecuador: Napo; Succumbios.
Syssphinx jasonoides Colombia: Valle, 1600-1800m.
Syssphinx centrichuchuviana northwestern Ecuador: Esmeraldas: Chuchuvi; Pichincha: Rio Pachijal, 720m.
Syssphinx centrizamorana southeastern Ecuador: Zamora-Chinchipe, 1270m.
Syssphinx centriboyacensis Colombia: Boyaca; Togui; Santander; Cundinamarca, 1600-2080m.
Syssphinx centriantioquiana Colombia: Antioquia: Yarumal; Cocorna, 2020m.
Syssphinx ocellata, Peru: Cuzco and Puno; Bolivia: La Paz, 1000-2000m.
Syssphinx bezverkhovi, Venezuela: Carabobo: Rancho Grande El Limon, 800m.
Syssphinx bidmagdaleniana: Colombia: Magdalena: Minca, 1700m.
Syssphinx tatama, Colombia: Risaralda: Sanctuario, 2100m.
Syssphinx parocellata, Bolivia: Chuquisaca: 30 km S E of Padilla, 1600m.
Syssphinx lapazcellata, Bolivia: LaPaz: Santa Rosa, 1550m.
Syssphinx misionescellata, Argentina: Misiones: Dos de Mayo, 500m.

There are also Adeloneivaia species which are quite similar. Female Adeloneivaia have quadripectinate antennae, similar to the males. The females of Syssphinx have filiaform antennae. Males are much more difficult to distinguish as to Genus.

Syssphinx bidens, female, Lita (Esmeraldas), Ecuador, courtesy of Horst Kach,
more likely Syssphinx centrichuchuviana, based on location.

FLIGHT TIMES AND PREFERRED FOOD PLANTS:

Syssphinx bidens moths are on the wing in February-March and September, suggesting at least two broods annually. A rearing of March eggs yielded adults in mid July, suggesting three broods or possibly even continuous brooding.

Larvae feed on Gleditsia triacanthos.

Syssphinx bidens female, Esmeraldas, Ecuador, courtesy of Uwe Kauz,
more likely Syssphinx centrichuchuviana, based on location.

Females can be extremely plump with eggs.

Syssphinx bidens female (verso), Esmeraldas, Ecuador, courtesy of Uwe Kauz,
more likely Syssphinx centrichuchuviana, based on location.

ECLOSION, SCENTING AND MATING:

Syssphinx bidens moths tend to eclose in the evening with scenting and mating occuring the same night between 10:00 pm and 2:00 am.

Syssphinx bidens courtesy of Bernhard Wenczel.:
probably S. bidens if from Venezuela; lower moth something else (WO?).

EGGS, LARVAE AND PUPAE: Syssphinx bidens moth females deposit flattened light green ova either singly or in pairs on hostplant foliage. Eggs are translucent and caterpillar development can be seen through the eggshell. Warm weather results in a very short incubation time of five days. Syssphinx bidens, more likely Syssphinx centrichuchuviana, based on location eggs, July 2006, courtesy of Uwe Kauz.

The orginal female was reportedly taken from Lita, Esmeraldas Province, Ecuador. I am not sure if there is a Lita in Esmeraldas (report may refer to Rio Lita), but there is a Lita (well known) in Imbabura Province. If from Esmeraldas, the Uwe Kauz images are most likely Syssphinx centrichuchviana.

Syssphinx bidens second instar, August 2006, courtesy of Uwe Kauz,
more likely Syssphinx centrichuchuviana, based on location.

Syssphinx bidens very early fourth instar, August 2006, courtesy of Uwe Kauz,
more likely Syssphinx centrichuchuviana, based on location.

Syssphinx bidens fifth instar, September 2006, courtesy of Uwe Kauz,
more likely Syssphinx centrichuchuviana, based on location.

Larvae mature at various rates and have the enlarged thoracic scoli typical of Syssphinx. Silver, metallic markings reflect light at night. Pupation is in a subterranean chamber with eclosions following in as little as two weeks.

Syssphinx bidens larva copyright Kirby Wolfe;
Probably S. bidens if from Venezuela.

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.

Gleditsia triacanthos.......... Robinia pseudoacacia

Honeylocust False Acacia; maybe

Return to Syssphinx Index

Return to Main Saturniidae Index

The pronunciation of scientific names is troublesome for many. The "suggestion" at the top of the page is merely a suggestion. It is based on commonly accepted English pronunciation of Greek names and/or some fairly well accepted "rules" for latinized scientific names.

The suggested pronunciations, on this page and on other pages, are primarily put forward to assist those who hear with internal ears as they read.

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

The genus name "Syssphinx" was probably chosen for the similarity of these moths (wing shape and resting position) to moths in the Sphingidae family.

The species name "bidens" is Latin for "two-toothed". The reference is probably to one of the genitalic structures.