A morphological appraisal of the new subfamily Epidesmiinae (Lepidoptera: Geometridae) with an overview of all geometrid subfamilies
Author
Murillo-Ramos, Leidys
Author
Friedrich, Egbert
Author
Williams, Steve
Author
Wahlberg, Niklas
Author
Brehm, Gunnar
Author
Sihvonen, Pasi
text
Zoological Journal of the Linnean Society
2021
2021-03-10
193
4
1205
1233
https://doi.org/10.1093/zoolinnean/zlaa189
journal article
3110
10.1093/zoolinnean/zlaa189
fde4f5ba-1117-4174-a8a2-07b06a82a94d
0024-4082
5761594
GENERAL DESCRIPTION OF
EPIDESMIINAE
Head and thorax (
Figs 1
,
6–15
)
Antennae unipectinate in males, shorter towards the apex (bipectinate in 2/5
Adeixis
species
and
Arcina
); filiform in females (shortly bipectinate in
Systatica
and
Abraxaphantes
). Labial palps elongated, second segment longest (less pronounced in
Systatica
); vom Raths’s organ an elliptical invagination. Frons elongated in many species. Chaetosemata small. Tegula large. Epiphysis small. Spur formula in male and female tibia 0–2–4 (hind leg with 2 + 2 spurs). Male hindleg hair-pencil absent (present in
Phrataria replicataria
Walker, 1866
). Metathorax furca with well-developed apophyses; anterior and basal ventral laminas separate.
Abdomen (
Figs 1
,
6–15
)
Abdomen slender. Tympanal organs large, almost meeting medially in a few species; tympanal organs approaching 45° angle relative to the abdomen; the posteromedial corner with narrow sclerotizations that extend into second sternite (pronounced in
Abraxaphantes
and
Epidesmia
). Ansa shape variable, ranging from evenly tapering and narrow rod to bottle-shaped with pickaxe-shaped apex. Second sternite often distinctly sclerotized, in few species with sternotympanal process with free end curved over tympanum (
Figs 6
,
14
). Abdominal sternites and tergites of both sexes undifferentiated, with few exceptions (e.g. posterior margin of male eighth sternite bilobed and setose in
Epidesmia tricolor
). Male third sternite with a row of setae in few species (
Epidesmia
,
Dichromodes
).
Wings (
Figs 1
,
2
,
4
,
5
)
Pattern, size and shape variable (
Fig. 1
). Colour varies from different shades of brown to yellowish, grey and white. Wingspan from
20 to 70 mm
. Forewing outer margin distinctly convex (
Ecphyas
and
Systatica
), weakly convex or concave. Forewing apex acute or rounded. Forewing venation: two areoles formed by R + Rs1–4; Rs1–Rs3 often stalked; cross-veins between M1 and M3 reduced, weakly tubular. CuA1 not stalked with M3. Hindwing venation: Sc + R1 parallel for long-distance with Rs; cross-veins between M1 and M3 reduced, weakly tubular. M2 tubular. One tubular A vein. Frenulum small. Resting posture of wings varies from planiform (for instance
Systatica
) to tectiform (for instance
Phrixocomes
) and potentially veliform (the latter is supported by a distinctly coloured underside and frequent observations of specimens with the wings partly or fully vertically folded over the abdomen in
Phrataria
) (
Fig. 2
).
Male genitalia (
Figs 6–15
)
Uncus long, narrow (short in
Ecphyas
). Socii minute, setose (reduced, barely recognizable in
Adeixis
). Gnathos distinct, arms fused, apically granulate, spinose or dentate. Tegumen narrow. Opened valvae upright (but nearly horizontal in
Dichromodes
), mobile (fused in
Ecphyas
), setose ventrally, with narrow or round projections (absent in
Systatica
and
Phrataria
, and projections present or absent in
Dichromodes
). Juxta variable, often sclerotized and bifurcate. Vinculum narrow. Transtilla often with two large, sclerotized, triangular lobes laterally, arms weakly sclerotized or membranous medially, barely fused. Saccus round (angled in
Systatica
). Coremata absent. Aedeagus variable, cornutus single (two cornuti in
Dichromodes confluaria
,
D. euscia
and
D. stilbiata
C. Byrne
, pers. comm.) or absent, vesica surface often covered with sclerotized granules. Vesica large, with diverticula.
Figure 1.
Adults of
Epidesmiinae
genera. Type species of each genus is illustrated, except in
Phrataria
, where a similar species is illustrated instead. A.
Ecphyas holopsara
male. Australia, WA, Albany, Torndirrup NP, 5.1.1993, coll. ANIC. B, C.
E. holopsara
female. Australia, WA, Leeuwin-Naturaliste NP, 5.1.2015, coll. Friedrich. D.
Arcina fulgorigera
male. Australia, WA, Talling, WA, 200 m, 3.11.2003, coll. ANIC. E, F.
A. fulgorigera
female. Australia, WA, Icy Ck, Lane Pool Res. 300 m, 6.11.2003, coll. ANIC. G, I.
Systatica xanthastis
male. Australia,
Victoria
, East Gippsland, 2.1.2012, 300 m, coll. Friedrich. H.
S. xanthastis
female. Australia, QLD, Binna Burra Lamington NP, 15.11.1992, 700 m, coll. ANIC. J, L.
Phrataria replicataria
male. Australia,
Victoria
, Gisborne, 17.2.1901, coll. NHMUK. K.
P. replicataria
female. Australia,
Victoria
, Gisborne, 10.3.1901, coll. NHMUK. M, O.
Phrixocomes ptilomacra
male. Australia, WA, 37 km SW of Mt. Ragged, 2.11.1977, coll. ANIC. N.
P. ptilomacra
female. Australia, WA, 37 km SW of Mt. Ragged, 2.11.1977, coll. ANIC. P.
Epidesmia tricolor
male. (without locality, without date) Pres. by Lady Lochore to B. M. 1946-341, coll. NHMUK. Q, R.
E. tricolor
female. Australia, NSW, Lindfield, 22.12.1974, coll. ANIC. S.
Dichromodes indicataria
male. Australia,
Victoria
(without date). coll. NHMUK. T, U.
D. indicataria
female. Australia,
Victoria
(without date). coll. NHMUK.. V.
Adeixis inostentata
male. New Caledonia, Grand Lac, 19.5.1971, 250 m, coll. NHMUK. W, X.
A. inostentata
female. New Caledonia, Grand Lac, 19.5.1971, 250 m, coll. NHMUK. Y, AA
Abraxaphantes perampla
male. Thailand, Chiangmai, Thoeng Dang, 7.4.2006, 500 m, coll. Sihvonen. Z.
A. perampla
female. Thailand, Chiangmai, Thoeng Dang, 7.4.2006, 500 m, coll. Sihvonen.
Figure 2.
Adults of
Epidesmiinae
, showing different resting positions (A–E) and a ‘dancing’ specimen of
Phrataria bijugata
, see text for details. Photos printed with permission, see Acknowledgements for details. A,
Systatica xanthastis
, Australia, Queensland, Tamborine Mtn., 8 Oct. 2016, photo Nicholas Fisher. B,
Dichromodes atrosignata
, Australia,
Victoria, Wilsons Promontory
, 22 Sept. 2006, photo Peter Marriott. C,
Phrixocomes ophiuca
, Australia,
Victoria, Davis Creek, Mallacoota
, 1 Nov. 2010, photo Marilyn Hewish. D,
Abraxaphantes perampla
, Thailand, 19 Feb. 2012, photo Tim Stratford. E,
Epidesmia tricolor
, Australia, New South Wales, 16 Feb. 2009, photo Denis Wilson. F,
Phrataria bijugata
, Australia,
Victoria, Eppalock
, 24 Jan. 2012, photo Steve Williams.
Female genitalia (
Figs 6–15
)
Two signa (in 5/9 genera), one stellate or granulate wide plate, another long, granulate or spinose narrow plate, both in mid-part of corpus bursae either ventrally or laterally; or one stellate or irregular-shaped signum (in 4/9 genera) in mid-part of corpus bursae either ventrally or laterally. Corpus bursae pyriform or constricted and narrower before anterior end, posterior part with sclerotized striations (in 5/9 genera). Ductus bursae length and degree of sclerotization variable. Shape and degree of sclerotization of lamella antevaginalis and lamella postvaginalis variable. Papillae anales round or weakly elongated, setose.
Morphology of individual
Epidesmiinae
genera (
Figs 6–15
)
Morphology of each genus was studied using the
type
species, and in species-rich genera other material was studied also. We are aware that as more material is examined, in particular in
Dichromodes
, we will gain a more accurate understanding of variation within each genus. Therefore, we do not provide detailed descriptions of genera, but instead illustrate relevant morphological structures in the colour plates provided. Selected structures are highlighted with arrows. The highest variation in the morphological structures are found in wing pattern and size; the number, position and shape of signa; shape of corpus bursae and its sclerotizations; tympanal organs; valva shape and its ornamentations; and in labial palps. Variation and similarities in these are useful in diagnosing the
Epidesmiinae
genera, and other groups within
Epidesmiinae
, for instance, if a tribelevel classification within the subfamily is needed later. The morphological variation should be compared against the molecular phylogenetic hypothesis of
Epidesmiinae
(
Murillo-Ramos
et al.
, 2019
) to see if correlations exist.
Distribution, biology and immature stages (
Fig. 3
)
Epidesmiinae
have an Australasian distribution with species recorded from
Australia
,
New Zealand
,
New Caledonia
and eastern
Papua New Guinea
. Monotypic
Abraxaphantes
is the only Indo- Malayan representative, recorded from
Thailand
and southern
China
.
Dichromodes
is the most diverse genus with 67 described species (Scoble & H a u s m a n n, 2 0 0 7), b u t p o t e n t i a l l y o v e r 2 0 0 additional species await description (
Marriott, 2012
). Several species fly commonly during the day and fly a short distance when disturbed in heath and grassy areas, but are also attracted to light during the night (
Marriott, 2012
). Little information is available on immature stages. Eggs are laid singly by
Phrataria bijugata
(Walker, 1863)
and
Epidesmia hypenaria
(
Guenée, 1857
)
. Those are turquoise blue when laid and darken as they develop. The first instar larva of
P. bijugata
is faint pink, and its abdomen is curved when resting.
Epidesmia tricolor
larvae have been recorded feeding on tea tree (
Leptospermum
J.R.Forst. & G.Forst.
;
Myrtaceae
) (
Scoble, 1999
) and
Dichromodes
have been reared on
Eucalyptus
L’Hér.
(also
Myrtaceae
).
Dichromodes
larvae are characteristically long and thin, and camouflaged to resemble small dead twigs of the hosts.
Dichromodes anelictis
Meyrick, 1890
showed high host specificity and was successfully reared on
Eucalyptus viridis
R.T.Baker
(green mallee). This moth occurs in autumn and can be prevalent at that time in ‘mallee areas’ but is absent in different habitats. In contrast, the larva of
Epidesmia chilonaria
is polyphagous and was easily raised on
Eucalyptus melliodora
A.Cunn. ex Schauer
and that of
Epidesmia hypenaria
fed on
Eucalyptus camaldulensis
Dehnh.
(river red gum) and
Eucalyptus macrorhyncha
F. Muell. ex Benth.
(red stringybark). Small and fully grown larvae of
Ep. chilonaria
are shown in
Figure 3E, F
. Larvae of
P. bijugata
, shown in
Figure 3B
, proved difficult to rear and it took several attempts to identify host preferences. Feeding was eventually observed on
Eucalyptus polyanthemos
Schauer
and
Eu. melliodora
, where leaves were skeletonized from the edge. These larvae did not survive beyond the second instar, probably indicating that the preferred eucalypt host has yet to be identified. The first instar larvae of
Phrixocomes hedrasticha
Turner, 1936
showed some interest in a number of the local shrubs of
Victoria
but did not establish. The larvae of
Dichromodes
,
Epidesmia
and
Phrixocomes
that have been reared, show a propensity to remain rigid, stationary and often in plain sight during the day and actively feed at night.
Adeixis inostentata
occurs in herbaceous marsh association in
Australia
, three
Adeixis
species
were found
on
Baeckea
-sedge maquis on sedimentary rock in
New Caledonia
and
A. griseata
occurs in characteristic ‘pakihi’ country, poorly drained acid areas with sedges and scattered low shrubs in
New Zealand
(
Holloway, 1979
).
Larvae
of
Adeixis baeckeae
Holloway, 1979
have been reared
on
Myrtaceae
:
Baeckea ericoides
(
Holloway, 1979
)
.
This
species pupates in loosely constructed cocoons in the terminal leaves of
Baeckea
, and emerges about 25 days after pupation (
Holloway, 1979
).
Structural
details of pupa, such as the arrangement of cremaster setae, are not available.
The
habitus of
Ep. chilonaria
pupa is shown in
Figure
3F
. Adults of
Epidesmia tricolor
fly in or near wet forests in southeastern
Australia
. For more information on phenology, see
Figure 17
.