Systematics, revisionary taxonomy, and biodiversity of Afrotropical Lithocolletinae (Lepidoptera: Gracillariidae)
Author
Prins, Jurate De
Author
Kawahara, Akito Y.
text
Zootaxa
2012
2012-12-20
3594
1
1
283
http://dx.doi.org/10.11646/zootaxa.3594.1.1
journal article
20704
10.11646/zootaxa.3594.1.1
79af20a5-77f9-4240-ac45-e27fab775ca1
11755334
6052126
B00799F3-F397-438C-B1E1-A8440E636921
Cremastobombycia
Braun, 1908
Cremastobombycia
Braun 1908: 272
(key), 349.
Type species:
Lithocolletis solidaginis
Frey & Boll, 1876
, by subsequent designation by
Meyrick 1912b: 11
.
Cremastobombycia
was established to denote a subgenus of
Lithocolletis
Hübner, 1825
.
Historic account.
Based on the stalked M
1
and M
2
in both forewing and hindwing,
Braun (1908)
erected the subgenus
Cremastobombycia
after differentiating it from the genus
Lithocolletis
.
Braun (1908)
also presented a dichotomous key and added valuable information on the immature stages of
Cremastobombycia
. She presented five putative characters that diagnose the immature stages of
Cremastobombycia
: i) larva cylindrical without prolegs on segment X; ii) host plants restricted to the family
Asteraceae
, iii) mines constructed on the lower (abaxial) surface of the leaf, except
C. grindeliella
which can mine on both sides; iv) the loosened epidermis of the mature mine very much wrinkled, and v) the cocoon rests suspended inside the mine on silken threads attached at the posterior and anterior ends.
Braun (1908)
placed five North American species into
Cremastobombycia
:
C. grindeliella
(
Walsingham, 1891
)
,
C. solidaginis
(
Frey & Boll, 1876
)
,
C. ambrosiella
(
Chambers, 1871
)
,
C. ignota
(
Frey & Boll, 1873
)
, and
C. verbesinella
(
Busck, 1900
)
.
Busck (1909)
gave credit to the work of
Braun (1908)
, however, he continued to search for the placement of
Cremastobombycia
within
Lithocolletinae
.
Busck (1909)
concluded that despite the structurally identical characters present in the imaginal stages, each group of
Lithocolletinae
has retained its typical larval development, feeding habits, peculiar cocoons and its typical forewing coloration.
Busck (1909)
followed
Braun (1908)
and postulated the placement of
Cremastobombycia
in
Lithocolletinae
. He placed
Cremastobombycia
Braun
and
Porphyrosela
Braun
in equal merit of the classification rank as
Phyllonorycter
and
Cameraria
,
however not transferring officially these former taxa to the genus rank and clearly recognized only two genera:
Phyllonorycter
and
Cameraria
,
considering
Cremastobombycia
as a subgenus of
Phyllonorycter
. However, he (
Busck 1909: 100
) wrote the following: “We have been doing our classification too much horizontally, so to say …. without sufficient regard to its origin. This does not produce a natural system.” However, a year later, probably after reading the argumentation and phylogenetic considerations on the relationship of species groups within
Lithocolletinae
by
Braun (1909)
,
Busck (1910)
described a sixth species,
Cremastobombycia lantanella
,
feeding on
Lantana
sp. (Verbenaceae)
from Honolulu, Oahu, Hawaiian Islands and assigned it to the genus
Cremastobombycia
. In 1902,
C. lantanella
was intentionally introduced from Mexico into the Hawaiian islands to aid in the control of
Lantana
sp.
(
Busck 1910
;
Swezey 1910
,
1913
). No additional species have been added since then.
Meyrick (1912b)
catalogued
Cremastobombycia
as a taxon of generic rank and designated the type species
Lithocolletis solidaginis
Frey & Boll, 1876
. The more specific studies that followed later mainly addressed evolutionary (
Braun 1914
;
Ely 1918
,
Davis & Robinson 1998
), morphological (
DeGryse 1916
;
Mosher 1916
;
Needham
et al
. 1928
), biological (
Swezey & Bryan 1929
;
Fontes
et al
. 1994
;
Palmer & Pullen 1995
;
Broughton 2000
), taxonomic (
Fletcher 1929
;
Zimmerman 1978
;
Aarvik
et al
. 2000
), and faunistic aspects of the genus (
Forbes 1923
;
McDunnough 1939
;
Brower 1984
;
Handfield 1997
; van Orden
Covell 1999
;
Powell & Opler 2009
). The phylogenetic position of
Cremastobombycia
at the time was unstable, but
Braun (1914)
was convinced that the genus is of “comparatively recent origin”.
Vári (1961)
, illustrated the type species,
C. solidaginis
for comparitive purposes, the genus has not been found in Africa until now. According to
Vári (1961)
Cremastobombycia
is related to
Protolithocolletis
, but differs from the latter genus by the absence of vein R
2
in the forewing. A preliminary phylogeny of
Gracillariidae
places
Cremastobombycia
clearly within
Lithocolletinae
, as the sister genus to
Phyllonorycter
(
Kawahara
et al
. 2011
)
, a result that is corroborated by wing venation (
Braun 1908
;
Busck 1909
).
Cremastobombycia
was thought to be distributed only in the New World and
C. lantanella
to the Neotropical region (
Busck 1910
; Palmer & Puller 1995;
Baars & Neser 1999
). There was no evidence yet that
C. lantanella
occurs in the Afrotropical region (
Baars & Neser 1999
,
Urban
et al
. 2011
). We have discovered two native Afrotropical
Cremastobombycia
species
,
C. kipepeo
De Prins
,
n. sp.
and
C. morogorene
De Prins
,
n. sp.
, and describe both herein.
Diagnosis
.
We define the genus
Cremastobombycia
as the assemblage of species-group taxa which fall into the clade
Cremastobombycia
(
Fig. 4
). According to wing venation
Cremastobombycia
is similar to
Phyllonorycter
Hübner, 1822
(
Braun 1908
;
Busck 1909
),
Protolithocolletis
Braun, 1929
(
Vári, 1961
)
and in adult external features to
Cameraria
: adults are rust-colored moths with silvery-white outwardly margined fasciate and/or strigulate markings on the forewing. Vertex more or less smooth with tufted filiform hairs mainly on occiput, what differs this genus from
Cameraria
which attain the tufted vertex.
Cremastobombycia
can be separated from
Cameraria
and other
Lithocolletinae
genera in that the forewing M
1
is stalked with M
2
, attaining a total of 6 apical veins, much like in
Hyloconis
and
Protolithocolletis
whereas forewing of
Porphyrosela
possess 5 apical veins as in
Cameraria
and
Phyllonorycter
. In the hindwing, the median vein is bipartite, forming M
1
and M
2
like in
Porphyrosela
,
Hyloconis
, and
Protolithocolletis
. The interocular suture is thick and strongly sclerotized, arc-shaped (well seen in descaled head). Occular indices of
Cremastobombycia
similar to
Cameraria
and
Phyllonorycter
: the occular index is approximately 0.6 and the interocular index is ca. 1.3. Palpi of
Cremastobombycia
are similar as in other
Lithocolletinae
genera: maxillary palpus small, rudimental, bi-segmented, apical maxillary palpomere almost globular, labial palpus moderate, porrect, filiform, drooping, straight, with ratio of segments from base 1: 1.4: 2. Sternum VIII in males forms a characteristic flap laying ventrally under the valvae as in many lithocolletine genera except
Chrysaster
,
Leucanthiza
,
Macrosaccus
, and
Protolithocolletis
, mostly tapering caudally, with rough lateral edges, setose.
Cremastobombycia
differs from
Cameraria
and other
Lithocolletinae
, except
Hyloconis
, in the number of apical setae of the tegumen: beside the main pair of long setae, the apex of the tegumen in
Crematobombycia
has 2–4 additional pairs of shorter apical setae. However, differently from
Hyloconis
,
Cremastobombycia
possesses a complete transtilla, a sclerotized anellus, and sometimes a well developed juxta. The valva in
Cremastobombycia
is stiff, not flexible as in
Cameraria
, with an enlarged cucullus area covered with short, thick, spinulae-like setae. The female genitalia may be asymmetrical. The ostium bursae in the type species opens at the right side at the posterior margin of segment VII. Segment VIII is short and firmly fused to segment VII. Posterior apophyses with conspicuous triangular appendix at basal 1/3 (
C. solidaginis
). Anterior apophyses arise at the boundary of segment VIII and VII. Ductus bursae strongly melanized along its entire length. The corpus bursae usually is well differetniated from the ductus bursae and usually has one signum. The bulla seminalis may be larger than corpus bursae (
C. solidaginis
). The ductus spermatecae is usually very long, ca. 60 revolutions, loose distally; the bulla spermathecae is sickle-shaped.
Braun (1908)
indicated that larvae of
Cremastobombycia
are cylindrical, without prolegs on segment X. However, diagnostic characters of the larva and pupa beside those indicated by
Braun (1908)
still need to be carefully examined.
Cremastobombycia
feeds on
Asteraceae
(
Braun 1908
;
De Prins & De Prins 2012
), except
C. lantanella
,
which feeds on
Verbenaceae
.
Cremastobombycia
larvae construct tentiform mines on the underside of leaf, except
C. grindeliella
which can sometimes mine both sides of a leaf (
Braun 1908
). Pupation occurs inside the mine, inside a suspended, spindle-shaped white silken cocoon, sometimes ornamented with longitudinal ridges (
Braun 1908
).
Diagnosis of Afrotropical
Cremastobombycia
. Afrotropical
Cremastobombycia
species
show differences in wing venation and male genital characters from the Neartic congenerics (see ‘examined additional type specimens used for generic diagnosis’). However, based on the shared similarities of the hindwing venation, forewing pattern, and genital morphology we assign the two Afrotropical species,
C. kipepeo
and
C. morogorene
to
Cremastobombycia
. A third Afrotropical species, belonging to
Cremastobombycia
,
C. lantanella
Busck, 1910
was mentioned as a probable invasive pest species to South Africa by
Baars & Neser (1999)
. However, no specimens belonging to this species were detected. Baars & Neser might have confused
Cameraria lantanella
with the another African gracillariid,
Aristaea onychota
(
Meyrick, 1908
)
, which has a very similar wing pattern and also feeds on
Lantana
. The two Afrotropical
Cremastobombycia
species
are very distinctive in external and internal morphological features.
Head:
Vertex not tufted, long piliform scales roughly tufted on occiput, mostly projecting forwards between antennae; frons smooth, shiny white; eyes big. Antenna ca. as long as forewing, smooth scaled, filiform; scape short thickened, bearing pecten of different length. Proboscis developed, naked, of medium length, ca. 2× longer than labial palpus. Maxillary palpus small, rudimentary. Labial palpus moderate, porrect, filiform, drooping, straight.
Thorax
: Forewing ground colour ferruginous-ochreous with white and black or only black markings; white markings are margined apically. Descaled forewing lanceolate, slender, and pointed. Afrotropical
Cremastobombycia
differs from the type species,
C. solidaginis
, in that forewing is broader and shorter: maximum width/length ratio in
C. solidaginis
is 0.17, maximum width/length ratio in
C. kipepeo
is 0.26; and in
C. morogorene
it is 0.19. Forewing ventation of
C. kipepeo
and
C. morogorene
has 8 veins, apical part with 5 veins R
3
, R
4
, R
5
, M
1
, Cu
1
; M is single, differently from
C. solidaginis
, where M
1
is stalked with M
2
, and apical part in
C. solidaginis
with 6 veins; the cell between R
4
and R
5
open in
C. kipepeo
, closed by a very slender rudimentary vein in
C. morogorene
, Cu
1
separate, CuP indistinct (fold) over entire length, 1A strong, separate. Hindwing lanceolate, maximum width / hind wing length 0.16, venation reduced to 5 veins as in
C. solidagini
s: Sc very short terminating near base of costa, Rs very long, running nearly to apex of hindwing, M branched to M
1
and M
2
, basal 2/3 of M
1
indistinct, parallel to Rs, Cu
1
strong, ends slightly beyond 1/2 of dorsum; A
1
vestigial. Frenulum in male—a single stout bristle, frenula in female—2 tightly appressed bristles, retinaculum—a small fold on Sc. Legs slender, with darker rings; epiphysis on foreleg absent, mesothoracic tibia bears a pair of spurs; hind tibia thickened, with long fine loose hairs, long medial and short apical spurs, hind tarsus smooth, slender and ca. 1.5× longer than tibia.
Abdomen
. The anterior boundary of abdomen opening sclerotized; S2 apodemes of median length, ending just before the opening, slender, with broader bases, slender distally. Sternum VIII in adult males well developed, flaplike, extended, tapering caudally, with gently rounded apex.
Male genitalia
. Tegumen rather long, with a pair long and many short (
C. kipepeo
) or 5 pairs of equal length (
C. morogorene
) apical setae. Valvae symmetrical, long, straight, with enlarged cucullus area or apical part of valva. Apex of valva is densely setose (
C. kipepeo
) or setose only on ventral and caudal margins of sacculus (
C. morogorene
). Transtilla complete, juxta small. Anellus tubular in
C. kipepeo
. Vinculum slender and can be apically bipartite (
C.
morogorene
). Aedoeagus thick, sclerotized in
C. kipepeo
and slender with enlarged coecum in
C. morogorene
; vesica either with cornuti (
C. morogorene
) or a barb-shaped appendage (
C. kipepeo
).
Female genitalia
. Papillae analles flat caudally, fused, with sclerotized outer rim. Segment VIII short, weakly sclerotized. Posterior apophyses without enlarged bases, slender; anterior apophyses initiate at middle of segment VIII, slender, shorter than posterior apophyses. Ostium bursae opens at the posterior margin of segment VII at depth of sclerotized with dentate margin posterior extention of segment VII (
C. kipepeo
). Sterigma very strongly developed and sclerotized, can nearly cover entire sternum VII. Ductus bursae long, rather broad. Corpus bursae oval, mainly as a smooth enlargement of ductus bursae, with one-two signa area, of which one round plate is crossed by sclerotized signum (two short narrow rods, situated opposite each other in
C. kipepeo
); corpus bursae with 2 short spikes (
C. kipepeo
).
Biology
.
No biological data on Afrotropical
Cremastobombycia
is available. In the Nearctic region, larvae in this genus feed on
Asteraceae
. They produce a tentiform mine on the underside of the leaf (
Braun 1908
;
Busck 1910
;
De Prins & De Prins 2005
). Pupation occurs inside the mine, inside a suspended, spindle-shaped, white, silken cocoon (
Braun 1908
).
Distribution
.
Afrotropical
Cremastobombycia
occur in East Africa, coastal forest and/or savannah.
Relationships to other genera.
Cremastobombycia
+
Phyllonorycter
is strongly supported by the eight gene molecular dataset (BP = 100%; PP = 1.0). Although weaker, this clade is sister to
Cameraria
(BP = 70%; PP = 1.0;
Fig. 4
). See the section on
Phyllonorycter
for details on shared morphological features.