A new gall-inducing tortricid (Lepidoptera: Tortricidae: Olethreutinae) on lima bean (Phaseolus Lunatus; Fabaceae) from Costa Rica

2007·5.9 MB·

by  John W Brown

PROC. ENTOMOL. SOC. WASH.
109(2), 2007, pp. 265-276
A NEW GALL-INDUCING TORTRICID (LEPIDOPTERA: TORTRICIDAE:
OLETHREUTINAE) ON LIMA BEAN {PHASEOLUS LUNATUS; FABACEAE)
FROM COSTA RICA
John W. Brown and Kenji Nishida
(JWB) Systematic Entomology Laboratory, PSI, Agricultural Research Service,
U.S. Department of Agriculture, c/o National Museum of Natural History,
Smithsonian Institution, P.O. Box 37012, MRC 168, Washington, DC 20013-7012,
U.S.A. (e-mail: [email protected]); (KN) Sistema Estudios de Posgrado en
Biologia, Escuela de Biologia, Universidad de Costa Rica, 2060 San Jose, Costa Rica
(e-mail: [email protected])
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Abstract. Lusterala phaseolana, new genus and new species, is described and
illustrated from Costa Rica. The new genus can be distinguished from all other
Olethreutinae by its unusual male genitalia, with a digitate uncus covered with long
hairs and the absence of socii, and its distinctive forewing maculation (i.e., dark
brown with scattered iridescent scales). Assignment ofthe new genus to Grapholitini
is provisional based on the general appearance and chaetotaxy of the larva and
a feature ofthe wing venation (i.e.. Mo and M3 parallel and widely separated at the
base). The entire type series was reared from stem galls on lima bean, Phaseolus
lunatus L. (Fabaceae).
—
Resurnen. Se describen e ilustran un genero y especie nuevos, Lusterala
phaseolana, de Costa Rica. El nuevo genero puede distinguirse de resto de
Olethreutinae por el patron de las alas anteriores, con escamas iridiscentes dispersas,
y por la inusual genitalia del macho, sin socii y con un uncus grande, en forma de
lobulo y cubierto de pelos largos. La posicion de este nuevo genero en Grapholitini es
provisional. Todos los especimenes de serie tipo fueron obtenidos a partir de agallas
del tallo del frijol lima, Phaseolus lunatus L. (Fabaceae).
Key Words: gall, life history, neotropics, new genus, new species, taxonomy, Cydia
torostoma, Dolichogenidea
Gall-inducing in Lepidoptera was re- inson et al. 2006), gall-inducing by
viewed by Miller (2005) who recognized larvae of this family appears to be
39 species of Tortricidae in 14 genera a relatively rare habit that has evolved
worldwide as gall-inducers, which is independently numerous times in various
second only to Gelechiidae in the num- lineages. Known gall-inducers are found
ber ofgall-inducing species in any family primarily in three tribes, Cochylini (4
of microlepidoptera. Given that more genera) (Nishida and Adamski 2004,
than 9,100 species oftortricids have been Miller 2005 and references therein),
described (Brown et al. 2005), and hosts Grapholitini (3 genera) (Miller 2005),
have been documented for many (Rob- and Eucosmini (6 genera) (Miller 2005);
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266 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
single species are reported in Olethreutini Universidad de Costa Rica (1150 m),
(Miller 2005), Enarmoniini (Miller 2005), San Jose, where they were maintained
Euliini (Brown and Nishida 2003), and at ambient indoor temperature (23 to
Hilarographini (Brown et al. 2004). The 24^C). To examine their contents, galls
A
purposes of this paper are to describe were split open longitudinally. subset
and illustrate a new genus and species of of larvae and pupae and reared parasit-
Olethreutinae that induces galls on Pha- oid wasps were preserved in 75% EtOH.
seolus lunatus L. (Fabaceae: Papilionoi- As adult moths emerged they were killed
deae) in Costa Rica and to provide and pin-mounted.
comments on its biology. The new taxon Dissection methodology follows that
is placed provisionally in Grapholitini. presented in Brown and Powell (1991,
Phaseolus lunatus, the larval host plant 2000). Digital images of the life history
ofthe new tortricid, is known commonly were captured with a Nikon Coolpix®
as lima bean, sieva bean, or butter bean camera. Images of adults and genitalia
(Iziko Museums of Cape Town 2004). It were captured using a Microptics® dig-
is a vine that frequently grows in ital camera system and enhanced using
disturbed habitats and urban areas, Adobe Photoshop® and Illustrator®
climbing over adjacent vegetation software. Terminology for genitalia
(Fig. 8) and fences. The plant is common structures and wing venation follows
in tropical climates with distinct wet and Horak (1984). Terminology for larval
dry seasons (Sauer 1993). Although chaetotaxy follows R. Brown (1987).
Central and South American in origin Paratypes are deposited in The Natural
(Sauer 1993), it has been domesticated History Museum, London, United King-
for more than 8,500 years, and it now dom (BMNH); Instituto Nactional de
ranges in the New World from north- Biodiversidad, Santo Domingo de Her-
western U.S. to Argentina; it also occurs edia, Costa Rica (INBio); National
in Europe, central Africa. Madagascar, Museum of Natural History, Washing-
and the Philippine Islands (Missouri ton, D.C., U.S.A. (USNM); and Escuela
Botanical Garden 2005). In Costa Rica, de Biologia, Universidad de Costa Rica,
F. lunatus is known on the Pacific slope San Jose, Costa Rica (UCR). Vouchers
from sea level to about 1800 m elevation of larvae are deposited in USNM.
(INBio 1997, Missouri Botanical Garden
2005). The species has been targeted for Systematics
conservation of plant genetic resources Lusterala Brown and Nishida, new genus
(Vargas et al. 2003). Type species: Lusteralaphaseolana Brown
Materials and Methods and Nishida, new species.
Galls induced by Lepidoptera larvae Diagnosis. Lusterala can be distin-
were collected from F. lunatus between guished morphologically from other gen-
April 2000 and March 2002 in Quitirisi, era of Olethreutinae by the somewhat
Ciudad Colon (1050 m) and Aserri digitate, weakly sclerotized uncus of the
Centro (1300 m), both in San Jose male genitalia combined with the ab-
Province, Costa Rica. The climate at sence of socii (Fig. 2), and superficially
these two sites is considered "'tropical by the slightly upraised iridescent scales
humid" with three to six months of dry on an otherwise nearly uniform dark
season annually (Herrera and Gomez brown forewing (Figs. 1, 11).
1993). Galls were placed in transparent Lusterala is assigned to Olethreutinae
plastic bags and taken to the entomo- on the basis ofthe antenna with one ring
logical laboratory at Escuela de Biologia, of scales per flagellomere; the hindwing
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109, 2 267
Figs. 1-2. Lusteralaphaseolcma. 1, Holotype male (left side and mirror image). 2, Male genitalia of
(USNM
paratype, aedeagus in situ slide 84,931).
PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
268
Fig. 3. Female genitalia oiLusteralaphaseolana paratype (USNM slide 84,928).
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with cubital pecten; the male genitalia these characters, Lusterala is assigned
with the transtilla and gnathos absent, provisionally to Grapholitini.
the valva with a conspicuous basal Within Grapholitini, Lusterala is su-
excavation, and the aedeagus fused with perficially most similar to Gymnandro-
the anellus and juxta (Fig. 2); and the soma, Ecdytolopha, Thaumatotibia, and
female genitalia with two large hornlike relatives, characterized by a dark brown
signa (Fig. 3) (Horak 1998). Its tribal forewing with few distinct pattern ele-
assignment is considerably more diffi- ments. In addition, virtually all members
cult. The large, paired, hornlike signa of the Gymnandrosoma genus group are
(Fig. 3) exclude it from Bactrim, En- internal feeders. Lusterala can be distin-
dotheniini, and Gatesclarkeanini, and guished from that group of genera by
combined with the general aspect of the a more rounded forewing apex and the
male genitalia, from Olethreutini. Lus- absence of a white or pale dot near the
terala also lacks a modified anal region end of the discal cell characteristic of
in the hindwing and modified scales of that group; also, males lack secondary
the basal portion of the patagia, which sexual scales typical of the group
are characteristic of many male Ole- (Adamski and Brown 2001). The larvae
threutini. The dark brown color of the of Lusterala lack the large, sclerotized
forewing and the somewhat digitate un- pinacula, including the distinctive en-
cus densely covered with hairs are highly larged L-pinaculum ofthe prothorax and
reminiscent of those of Cryptaspasma the posteriorly displaced spiracle on A9
lugubris (Felder) and some other Micro- that are diagnostic for the Gymnandro-
corsini (see Diakonoff 1959, Brown and soma group (Adamski and Brown 2001).
Brown 2004), but Lusterala lacks virtu- According to Horak and Brown
ally all of the characters that define that (1991), Graphohtini may represent
tribe. While the number and arrange- a polyphyletic assemblage of genera in
ment of the cornuti in the aedeagus are which features of the genitalia and wing
similar to those of Ancylis (Enarmo- venation reflect parallel reductions rath-
niini), other features typical ofthat tribe, er than synapomorphies. In contrast,
e.g., falcate apex of forewing, valva Komai (1999) recognizes the shortened
usually with large basal excavation, sternum 8 in the male with a straight
a single or bifid thorn from the cucullus, posterior margin as a putative synapo-
and a pair oflarge angulate signa (Horak morphy for the tribe. In Lusterala the
2006), are lacking in Lusterala. The form sternum is not particularly short, and the
ofthe aedeagus and cornuti, the presence margin is slightly convex.
of an uncus, the long ductus bursae, and Description. Adult: Head: Frons
the saberlike signa suggest an affinity weakly convex, with small appressed
with Eucosmini; however, the venation scales; vertex with forward projecting
of the hindwing clearly contradicts this scales, approaching but not reaching
placement. Lusterala is superficially sim- base of labial palpus, each scale with
ilar to some species of Grapholitini; the a scalloped tip. Antenna ca. 0.5 as long
larvae are similar to many internal- as forewing length; setae less than 0.25
feeding Grapholitini (e.g., Cydia); the times width of flagellomere, much more
overall aspect of the male and female dense in males than in females; one row
genitalia are consistent with members of of scales per flagellomere. Labial palpus
that tribe; and hindwing veins M2 and short, ca. 1.2 times horizontal diameter
M3 are p—arallel and widely separated at of compound eye; first segment short,
the base a character that has been used upcurved; second segment longest,
to define Graphohtini. On the basis of densely scaled, ca. 6 times as long as
PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
270
third segment, slightly upcurved; third ed apically, costa very slightly undulate,
segment short, barely extending beyond cucullus well-developed in distal 1/4.
scaling of second. Maxillary palpus in- Aedeagus simple, long, ca. 4/5 length of
conspicuous. Proboscis developed, na- valva, vesica with 35-40 slender cornuti,
ked. Ocelli large, chaetosemata well de- sometimes in a dense, elongate patch and
veloped. A narrow band of long sometimes scattered throughout. Female
semierect scales from lateral posterior genitalia (Fig. 3) (2 preparations) with
part of vertex to occiput and surround- ovipositor short; papillae anales simple
ing compound eyes. Thorax: Dorsum with relatively short setae from papillate
and tegula smooth scaled; posterior tuft bases; apophyses long and slender,
weak, comprised of a patch of conspic- apophyses anteriores ca. 1.3 times the
uously broad, somewhat elongate-rect- length ofaphophyses posteriores; ostium
angular scales (worn and/or lacking in ringlike; a small cup-shaped antrum
most specimens). Legs unmodified. Fore- between ostium and ductus bursae;
wing with all veins present and separate sternite of seventh segment with a pair
beyond discal cell; discal cell ca. 0.65 of irregularly triangular, lightly sclero-
times length of wing; M-stem weak, tized areas antero-laterad to ostium;
chorda present forming short accessory ductus bursae relatively straight, ca. 2/3
cell arising ca. midway between Rt an R3 length of corpus bursae, slightly broad-
and extending to base of R5; base of R5 ened in anterior 1/2, membranous; duc-
closer to base of R4 than to base of Mi; tus seminalis from lateral right portion
M2, M3, and CuAi nearly parallel, with of ductus bursae ca. 2/3 distance from
bases nearly equidistant among them; ostium to junction with corpus bursae;
CuP weak, present only at wing margin; corpus bursae elongate-ovoid, without
anal loop ca. 0.35 times length of spicules; two large signa each consisting
1A+2A; male without costal fold. of a long, broad, straight, attenuate
Hindwing with veins Sc+R straight, thorn, weakly curved apically, from
closely parallel to Rs in basal 0.5; Mi a broad, round, invaginated, sclerotized
parallel to Rs in basal 0.25; M2 only pocket of the outer wall of corpus
sHghtly closer to M3 than to Mi at base;
bursae.
M2 and M3 parallel, widely separated at Etymology.—The genus name is from
bases; M3 and CuA] coincident at base; the Latin '"luster" (= illuminate), in
CuP present, but weak throughout; basal
reference to the iridescent scales of the
stem of CuP and 1A+2A setose. Frenu-
forewing, and the Latin ''akr (= wing).
lum in female with three bristles, male The gender is masculine.
with one. Abdomen: Sternum 8 in male
with slightly convex posterior margin; Liistevalaphaseolana Brown and Nishida,
coremata absent in male; no specialized new species
corythrogyne scales in female. Male
(Figs. 1-4, 11)
genitalia (Fig. 2) (3 preparations) with —
tegumen simple, ovoid; uncus moderate- Diagnosis. As presently defined, Lus-
ly large, somewhat digitate, rounded terala is monotypic. The single included
distally, weakly sclerotized, densely cov- species can be distinguished superficially
ered with long hairs somewhat thicker from all other Grapholitini by the sparse
distally; socius and gnathos absent; anal irregular lines and small patches of
tube poorly defined, represented by iridescent scales (slightly bluish) on the
round, weakly sclerotized region; valva forewing and dorsum of the thorax.
broadest in basal 2/5, slightly narrowed Distinctive morphological features in-
in middle, slightly dilated distally, round- clude the digitate uncus in the male
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surface of valva of male with sparse,
fine, pale brown scales; no conspicuous
specialized scales in male or female. Male
genitalia (Fig. 2) as described above for
genus. Female genitalia (Fig. 3) as de-
scribed above for genus.
Larva: Based on four probable last
instars. In general, the larva is short (8.0-
mm
8.5 in length), plump, and pale
cream or pinkish; the pinacula lack
distinct sclerotization; and the anal fork
is absent, features typical of many in-
ternal-feeding Olethreutinae, especially
Grapholitini (e.g., Cydia spp.). The
spiracles are distinctly ovoid, the pro-
thoracic spiracle is ca. 2.5 times the size
of the others, and the spiracle on
abdominal segment 9 is only slightly
larger than those of other abdominal
segments. The head is pale amber with
an extremely faint genal bar. The pro-
Fig. 4. Pupal exuviae ofLusteralaphaseolana; thoracic shield is ill-defined, represented
venter (on right) and dorsum (on left). by a pair of weakly sclerotized, triangu-
lar patches, one on each side of the
genitalia and the deeply invaginated, dorsum. The L-group on the prothorax
strongly sclerotized bases of the hornlike is bisetose, which is rare in Tortricidae.
signa in the female genitalia. Females are Although endophagous Tortricinae have
conspicuously larger than males. a propensity for the loss of one of the L
Description. Adult: Head: Frons and setae, this is seldom, if ever, the case in
vertex dark brown; labial palpus lighter endophagous Olethreutinae (Dugdale
brown with faint bluish iridescence. pers. comm.. Brown et al. 2004). The
Thorax: Dark brown with scattered SV-group on thoracic segments 1, 2 and
iridescent scales; posterior tuft a low, 3 is 2:1:1, typical ofTortricidae. The SV-
rounded patch of blackish brown scales. group on abdominal segments 1, 2, 7, 8,
Forewing length 6.9-8.0 mm (x = 7.1; n 9 is 2:2:2:1:1 (variable within most tribes
= 10) in males, 8.5-9.5 mm (x = 9.2; n = of Olethreutinae). On abdominal seg-
10) in females; dorsal surface entirely ment 8, seta SDl is directly anterior to
dark brown, with sparse irregular lines the spiracle. On abdominal segment 9,
and small patches of slightly upraised, the D2 setae are on a shared, unscler-
iridescent scales (reflecting slightly blu- otized, dorsal pinaculum; setae Dl and
ish), rarely with extremely sparse whitish SDl are on a shared pinaculum; and the
striae; costal strigulae extremely weak, L-group is bisetose. The distance be-
overscaled with brown; fringe dark tween the V setae on abdominal segment
brown. Undersurface uniform dark 9 is about two-thirds that between the V
brown. Hindwing dorsal surface dark setae of abdominal segment 8. The setae
brown, concolorous with forewing; of the anal shield are short. The prolegs
fringe pale cream; male without special- of abdominal segments 3-6 bear 25-35
ized scales. Undersurface uniform dark uniordinal crochets, the proleg of seg-
brown. Abdomen: Dark brown, outer ment 10 bears 8-10.
272 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Figs. 5-7. Lusteralaphaseokina gall. 5, Pupal exuviae protruding from gall. 6, Exit cover ofgall. 7,
Larva within gall chamber with exit cover opened.
Pupa (Figs. 4, 5): Based on 15 exuviae. dominal segments 2-7 with two distinct
Typically tortricoid, without conspicu- rows of spines, anterior row on segment
ous sculpturing or cephalic prominence; 2 with only 2-A small spines, posterior
mm
length 8.0-10.0 in males, 11.5- row well developed; anterior row on
mm
12.0 in females. Dorsum of abdom- segments 4—7 extending from spiracle to
inal segment 1 without spines and with spiracle. Dorsum ofabdominal segments
spiracle inconspicuous. Dorsum of ab- 8-10 with a single row of large thorns
8
,
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109, 2 273
Figs. 8-11. Habitat, gall, and resting posture ofLusteralaphaseolana. 8, Roadside habitat and host
(arrow indicates position of gall). 9, Globose gall induced by L. phaseolana (scale bar in mm/cm). 10,
Inside ofelongate gall induced by L. phaseolana showing larvae in chambers. 11, Adult L. phaseolana
resting on branch ofhost.
representing anterior row; no conspicu- Honda, 2 km hacia Quitirisi, 16 Apr
MH
ous hooked seta on abdominal segment 2000 (1 c?, 1 2), K. Nishida. Site 1, 1
10. Cremaster abs—ent. Mar 2000 (Ic?), 20 Mar 2000 {?>$), 31
Type material. Holotype S Costa Mar 2000 (1$), gregarious gall former
,
Rica, Provincia San Jose, Aserri Centro on Phaseolus lunatus, collected by M.-H.
(site E43), 1400 m, 7 Jun 2000, r.f. Kestemont, re—ared by K. Nishida.
Phaseolus lunatus, collected by M.-H. Etymology. The specific epithet is
Kestemont, reared by K. Nishida. De- derived from the host plant genus,
USNM.
posited in Phaseolus.
Paratypes: COSTA RICA: Provincia
Biology
San Jose: Aserri Centro (site E43),
1400 m, 8 May 2000 {\S), 10 May The galls of Lusterala phaseolana are
2000 {\$, 3$), 15 May 2000 (1$), 16 variable from elongate spindle-shaped to
May 2000 (3(?, 3?), 23 May 2000 {2S globose (Figs. 5, 9, 10). They were
1$), 3 Jun 2000 {2$, 1$), 7 Jun 2000 discovered on old (lignified) stems of
(Ic^", 1?), gregarious gall former on Phaseolus lunatus growing along road-
Phaseolus lunatus, collected by M.-H. sides (Fig. 8, arrow). The galls usually
Kestemont, reared by K. Nishida. Ciu- were located near the basal part of the
dad Colon, Quitirisi, De Quebrada plant close to the ground (Fig. 8). Gall-
274 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
induction usually caused wilting and pupa protrudes prior to adult emergence
eventual death of the plant (E. Castro, (Fig 5). Emerged adults perched on the
personal communication). A single large host (Fig. 10), where they were highly
gall (ca. 10 cm X 1.6 cm; stem diameter camouflaged by their barklike appear-
of 8 mm) contained as many as 12 last ance.
instar larvae (unilocular, i.e., one larva The galls ofLusterala are superficially
per chamber). Apparently, swelling of similar to those described for Cydia
the stem (i.e., gall) is the result of torostoma (Clarke) (Clarke 1972), which
enlarged parenchyma tissue. Several galls is also a pest of beans in Costa Rica
C
had a purplish tint in tissue that (Saunders et al. 1998). The adult of
surrounded the larvae or pupae. One torostoma is somewhat similar to that of
gall collected in Aserri Centro contained Lusterala; however, the similarity is
coexisting larvae ofLusteralaphaseolana merely the result of the shared absence
and Carmenta mimosa Eichlin and Pas- of distinct forewing pattern elements;
soa (Sesiidae). This gall was larger than i.e., both species are mostly nondescript
C
galls occupied by Lusterala alone. Lar- little brown moths; however, toros-
vae of C. mimosa, erroneously cited as toma has considerably more whitish
SynantJiedon sp. by Saunders et al. scaling on the forewing. The genitalia
(1998), are recorded as gall-inducers on of the two species demonstrate that they
some bean plants (Saunders et al. 1998) are not closely related.
including P. lunatus in Costa Rica (K. It is interesting that no specimens ofL.
Nishida, personal observation). phaseolana were discovered in the rather
Each larval chamber of last instar extensive Lepidoptera collection at IN-
Lusterala larvae (Fig. 10) was lined with Bio, suggesting that the species may be
silk, the chambers clustered together diurnal or possibly not attracted to ultra-
within the gall. Frass was present in violet light; the latter is the standard
spaces surrounding and between cham- collecting method. Hence, the discovery
bers and was more or less compacted. ofspecies related to Lusteralaphaseolana
Some of it protruded from the gall may require the rearing of larvae.
surface through the exit holes. Some A series of Doliehogenidea sp. (Hyme-
frass was exuded and attached along noptera: Braconidae: Microgastrinae)
shallow longitudinal grooves of the gall (determined by Alejandro Valerio) para-
surface (Fig. 9). sitoid wasps was reared from larvae ofL.
Last instar larvae reacted to gentle phaseolana. Several specimens of Peri-
probing with forceps by regurgitating lampus sp. (Hymenoptera: Perilampidae)
a translucent fluid. Agitated larvae kept (identified by Paul Hanson) also were
their mandibles open after regurgitating reared as a hyperparasitoid of Dolieho-
and aggressively moved toward and bit genidea sp.
at the source of agitation.
Acknowledgments
The pupal chamber in the gall is ca. 12
X 3 mm, cylindrical, and white to cream We thank Marie-Helene Kestemont
white. The outer surface ofthe cocoon is and Arnauld Thiry (Faculte des Sciences
brown and covered with frass. The exit Agronomiques de Gembloux, Gem-
hole from the chamber (Figs. 6, 7, 9) is bloux, Belgium) for sharing specimens
round, ca. 2.8 mm in diameter; each and for providing collecting data; Tom
larva has its own exit hole. The exit Eichlin (CaHfornia Department of Food
"valve" is penelliptical, constructed by and Agriculture, Sacramento, California,
silk with the peridermal layer ofthe plant USA) for identifying the sesiid moth;
tissue on the outside (Figs. 6, 7). The Oscar Rocha (University of Costa Rica,