Epsteinius Lin, Braby & Hsu

Lin, Yu-Chi, Braby, M. F. & Hsu, Yu-Feng, 2020, A new genus and species of slug caterpillar (Lepidoptera: Limacodidae) from Taiwan, Zootaxa 4809 (2), pp. 374-382: 376

publication ID


publication LSID




persistent identifier


taxon LSID


treatment provided by


scientific name

Epsteinius Lin, Braby & Hsu

gen. nov.

Epsteinius Lin, Braby & Hsu   , gen. nov.

( Figs 1–4, 11 View FIGURES 1–12 , 13, 14 View FIGURES 13–16 , 17 View FIGURES 17–18 , 29, 30 View FIGURES 19–33 , 36, 37, 45, 46 View FIGURES 34–46 )

Type species. Epsteinius translucidus Lin   , sp. nov. (here designated).

Diagnosis. Epsteinius   differs from Microleon   ( Figs 5–9, 12 View FIGURES 1–12 , 15, 16 View FIGURES 13–16 , 18 View FIGURES 17–18 , 34, 35, 43, 44 View FIGURES 34–46 ; Solovyev, 2008; Sasaki, 2016; Sohn et al., 2018) by the following characters: (1) adults are smaller in size—male forewing length of Epsteinius   is 5.3–5.5 mm compared with 6.3–7.9 mm for that of Microleon   ; (2) in Epsteinius   the hindwing is narrower with the termen rounded, whereas in Microleon   it is broader with the termen distinctly angular; (3) the labial palpus of Epsteinius   is shorter (approx. 2.0–2.5 times the diameter of the eye) than that of Microleon   (approx. 3 times the diameter of the eye); (4) in Epsteinius   the upperside of the forewing has the inner half dark brown with a purple iridescent suffusion, whereas in Microleon   there are usually two large irregular orange patches, one at base and the other in the median area of dorsum, and it lacks the purple suffusion; (5) in Epsteinius   the scale fringe of the hindwing is grey, whereas in Microleon   it is conspicuously black at the tornus.

In addition, the male genitalia of Epsteinius   ( Figs 13, 14 View FIGURES 13–16 ) differs from that of Microleon   ( Figs 15, 16 View FIGURES 13–16 ) in many characters, including the form of the gnathos which has a sharply down curved tip, the valva which has two long processes along the dorsal margin, and the phallus which is shorter and basally enlarged and rounded with two conspicuous cornuti. In contrast, the genitalia of Microleon   has the gnathos with a T-shaped end, no process along the dorsal margin of the valva, and a relatively straight phallus without cornuti. The female genitalia of Epsteinius   ( Fig. 17 View FIGURES 17–18 ) differs from Microleon   ( Fig. 18 View FIGURES 17–18 ) in having a short and wide ductus bursae, and an ovate corpus bursae containing two signa each with a row of flat complex teeth. In Microleon   , the ductus bursae is long and coiled, and the corpus bursae is ovate, containing only one signum with a set of sharp complex processes over its surface.

Although the early instar larvae of Epsteinius   ( Figs 24, 25 View FIGURES 19–33 ) and Microleon   spp. ( Figs 19, 20 View FIGURES 19–33 ) are very similar, they diverge considerably in color pattern and shape in the final instar larvae, as follows: (1) in Epsteinius   ( Figs 26, 27, 31, 32 View FIGURES 19–33 ) the shape of the body is elliptical, whereas in Microleon   spp. ( Figs 21, 22 View FIGURES 19–33 ) it is narrower with a humped dorsal surface; (2) in Epsteinius   there is usually an indistinct brown lateral patch (which varies among individuals), whereas in Microleon   spp. there is a distinct red subdorsal patch; (3) in Epsteinius   the body is semi-translucent, whereas in Microleon   spp. it is opaque; (4) in Epsteinius   the spine-bearing protuberances are similar to those of its early instars, whereas in Microleon   spp. the protuberances in the final instar diminish in size compared with its early instars.

Etymology. The generic name is named in honor of Marc E. Epstein for his enormous and longstanding contribution to the study of limacodid moths.