Two new species of Trichogramma (Hymenoptera: Trichogrammatidae) from the Ryukyu Islands, Japan

2005·2.8 MB·

by  Josephine Jose

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PROC. ENTOMOL. SOC. WASH.
107(4), 2005, pp. 782-788
TWO NEW SPECIES OF TRICHOGRAMMA (HYMENOPTERA:
TRICHOGRAMMATIDAE) FROM THE RYUKYU ISLANDS, JAPAN
Josephine Jose, Yoshimi Hirose, and Jeffrey Y. Honda
(JJ) Center for Biodiversity, Department of Biological Sciences, San Jose State Uni-
versity, One Washington Square, San Jose, CA 95192-0100, U.S.A. Present address: De-
partment of Entomology, 320 Morrill Hall, University of Illinois, 505 S. Goodwin Ave.,
Urbana, IL 61801, U.S.A.; (YH) Institute of Biological Control, Faculty of Agriculture,
Kyushu University, Fukuoka 812-8581, Japan. Present Address: 349 Asano, Munakata
811-3415, Japan; (JYH) Center for Biodiversity, Department of Biological Sciences, San
Jose State University, One Washington Square, San Jose, CA 95192-0100, U.S.A. and
Institute of Biological Control, Faculty of Agriculture, Kyushu University, Fukuok 812-
8581, Japan (e-mail: [email protected])
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Abstract. Two new species of Trichogramma Westwood from the Ryukyu Islands
were collected in green pepper fields using trap cards containing Ephestia kuehniella
Zeller (Lepidoptera: Pyralidae) eggs and from parasitized Plutella xylostella (Linnaeus)
(Lepidoptera: Yponomeutidae) eggs. ITS-2 sequences and scanning electron micrographs
were obtained for both Trichogramma species. Herein we describe Trichogramma cul-
tellus n. sp., and T. umerus, n. sp.
Key Words: Trichogramma, new species, Ryukyu Islands
Species of Trichogramma Westwood Materials and Methods
(Hymenoptera: Trichogrammatidae) in the
Species descriptions and specimens pre-
Ryukyu Islands are poorly known. Ishii
pared for scanning electron microscopy
(1938, 1941) first recorded T chilonis Ishii (SEM) and DNA analysis are based on
as an egg parasitoid of Tetramoera (= Eu-
methods described previously (Taylor et al.,
cosma) schistaceana (Snellen) (Lepidop-
in press). Species descriptions and mea-
tera: Totricidae) from Okinawa. Since then,
surements follow the anatomical terminol-
there have been no records of additional
species of Trichogramma from the Ryukyu ogy, morphological measurements, and ra-
Islands. In 1997, members of the Shimane tios (relative dimensions) used in Pinto
(1999). All types are deposited in the En-
Agricultural Experiment Station collected
tomological Laboratory, Faculty of Agri-
Trichogramma from trap Ephestia kuehn-
iella Zeller (Lepidoptera: Pyralidae) egg culture, Kyushu University (ELKU).
cards and from parasitized Plutella xylos-
Trichogramma cultellus Jose, Hirose,
tella (Linnaeus) (Lepidoptera: Yponomeu- and Honda, new species
tidae) eggs in Ishigaki and Iriomote Islands,
respectively. Unique ITS-2 DNA sequences (Figs. 1-6)
and microscopic examination indicated two Diagnosis. Trichogramma cultellus is
taxa that have not been previously de- similar to the following species: T. thalense
scribed. Herein we describe two new spe- Pinto and Oatman, T. parkeri Nagarkatti, T.
cies from the Ryukyu Islands, Japan. pintoi Voegele, and T. elegantum Sorokina.
VOLUME 107, NUMBER 4 783
Figs. 1-3. Trichoi^niiiiiiHi cullclliis. male. 1. Dorsal view ofgenital capsule; scale bar 5() \xm. 2. Ventral
view of genital capsule (IVP partially broken in preparation): .scale bar = .=^0 |uii. 3. Veiiirai \lew ol apical
distance (IVP partially broken in preparation); scale bar = 30 |xin.
784 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
The female ovipositor length is much short- ward apex, longest flagelliform setae 3.53
er in these species measuring 0.79, 0.86- ± 0.57X greater than FW; without unsock-
0.95, 0.84, and 0.95X the hind tibia length eted setae; basiconic peg sensilla (BPS) rel-
for T. thalense, T. parkeri, T. pintoi, and T. atively small, slightly inflated, formula 2-2-
elegantiim, respectively, vs. 1.04-1.07 in T. 2-1-1-1 (n = 6); terminal placoid sensilla
cultellus. The genital capsule is generally (PLS) with apical 0.23-0.34 extending be-
broader in T. thalense with a width to yond flagellum apex.
length ratio greater than 0.30. Ventral pro- Genital capsule (GC) relatively narrow,
cesses are also positioned at the base ofthe 0.30 ± 0.01 as wide as long; apical distance
intervolsellar process (IVP). In contrast, T. (AD) 0.19 ± 0.01 entire genital length
cultellus has a genital capsule width to (GL); apical width (AW) 0.68 ± 0.04 gen-
length ratio of about 0.30 and ventral pro- ital width (GW); dorsal aperture length
cesses located distinctly anterior to the base (DAL) 0.49 ± 0.02 GL; dorsal lamina
of the IVP. Flagella setae are much longer (DLA) arising in anterior half of GC with-
in T. cultellus measuring over 3.5X the fla- out approaching GC sides, slenderposterior
gellum width vs. T. pintoi (2.56X), T. par- DLA extension narrows and sharply tapers
keri (2.85X), and T. elegantum (2.2X). The toward apex occupying 0-0.42 AD (see
posterior extension of the dorsal lamina is Variation), width at level of intervolsellar
much narrower in T. cultellus and T. par- process (IVP) less than that of aedeagus;
keri than in T. pintoi. However, the dorsal DLA 1.68 ± 0.34 (see Variation) as long as
lamina is only 1.5X as long as wide in T. wide and 0.47 ± 0.04 GL; IVP short, sub-
m
cultellus but over twice as long as wide triangular, occupying 0.11-0.17 AD; vol-
T. parkeri. — sellae (VS) relatively straight, occupying
Description. Quantitative data taken 0.42-0.61 AD; ventral ridge (VR) narrow
from 7 males with a hind tibial length
mm and abruptly widening anteriorly, occupy-
(HTL) of0.14-0.16 and 2 females with
HTL = 0.14-0.15 mm unless otherwise in- ing 0.45-0.58 basal distance (BD); ventral
processes (VP) not obviously protuberant,
dicated. Color recorded from dried speci- slightly laterally displaced to VR and po-
mens wrapped in tissue paper. Both sexes
sitioned distinctly anteriorto IVP. Aedeagus
with extensive brown suffusion on meta-
length (AL) ca. equal to GL, 0.76 ± 0.07
soma and a dull yellow to tan mesosoma.
Forewing relatively narrow, 0.25 ± 0.01 (n = 6) HTL; apodemes occupying ca. 0.58
mm wide (n = 5); width (FWW) 0.52 ± AL.
0.02 length (FWL) (n = 5); setation rela- Female: Antennal funicle with 1 BPS on
tively sparse, 7-13 (n = 4) setae between firstfunicular segment (Fl) and 2 on second
4th and 5th setal tracks; longest fringe setae (F2). Ovipositor length (OL) 1.04-1.07X
0.13 ± 0.03 (n = 5) FWW, approximately that of HT—L.
1.5-2.IX hind tibial width (HTW). Hind Types. Holotype J: JAPAN. Okinawa
wing with (n = 2) and 3-5 (n = 2) setae Prefecture: Iriomote Island; 4 November
in anterior and posterior tracks, respective- 1997; E. kuehniella trap host; Y. Narai and
ly, the latter tract occupying 35-36% dis- N. Itagaki. Paratypes: 6 d, 19 including
tance from hamuli to wing apex. Scutellum allotype 9, sam—e data as holotype.
with anterior pair of setae 91-95% (n = 2) Etymology. Derived from the Latin
length of posterior pair. word cultellus meaning small knife, refer-
Male: Flagellum length (FL) 0.16-0.19 ring to the knife like appearance ofthe pos-
mm, approximately 2.4X longerthan scape, terior extension ofthe DLA, used as a noun
FL 6.57 ± 0.63X greater than flagellum in apposition.
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width (FW), FL 1.22 ± 0.1 IX greater than Variation. The posterior extension of
HTL; flagelliform setae long, tapering to- the DLA usually occupies 0.22-0.42 of the
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X
VOLUME 107, NUMBER 4 785
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Figs. 4-6. Trichogramma cultelhis. 4, Dorsal and ventral view of male genital capsule. 5, Forewing. 6.
Hindwing. Scale bars = 0.05 ixm.
AD, although in one ofthe paratypes it fails tively, vs. 0.85 for T. umerus. The T. min-
to reach the level of the AD. utum male is most easily differentiatedfrom
Remarks. Trichogramma cultellus keys T umerus in that the latter has longer fla-
to couplet 23' in Pinto's (1999) key to the gellar setae, a shorter ventral ridge, and a
North American Trichogramma but is sep- lesser extension ofthe terminal placoid sen-
arated from T. parkeri by characters dis- silla on the flagellum. From T pretiosum,
cussed in the Diagnosis section. T. umerus is most easily distinguished by
DNA sequence.—The 431 bp ITS-2 having broader shoulders on the dorsal lam-
DNA sequence has been deposited in the ina. The dorsal lamina width to length ra-
NCBI Database with the following acces- tios measure 1.38 and 1.67 for T. umerus
sion number: AY518693. We compared this and T. pretiosum, respectively.
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sequence with sequences of species includ- Description. Quantitative data from 8
ed in the Parkeri section to which T. cul- males with a hind tibial length (HTL) of
tellus belongs. A 581 bp T. pintoi (acces- 0.13-0.16 mm and 3 females with HTL =
sion AY182757) and a 556 bp T. bourara- 0.14-0.17 mm, unless otherwise indicated.
chae Pintureau and Babault sequence (ac- Both sexes apparently yellow with brown
cession AF043626) was found to be only suffusion on mesosoma and an entirely
39% and 46% similar to T. cultellus. brown metasoma.
Forewing narrow. 0.21 ± 0.02 (n = 7)
Trichogramma umerus Jose, Hirose, and mm wide; width (FWW) 0.47 ± 0.03 (n =
Honda, new species 7) length (FWL); 9-21 setae between 4th
(Figs.7-13) and 5th setal tracts (n = 5); longest fringe
Diagnosis. Trichogramma umerus most setae 0.19 ± 0.02 (n = 7) FWW, ca. 2.38
closely resembles T. pretiosum Riley and T. greater than hind tibial width (HTW) (n =
minutum Riley. Females ofthe latter species 7). Hind wing with 1-3 and 4-8 setae in
have a longer ovipositor, measuring 0.99 anterior and posterior tracts, respectively,
and 1.14X the hind tibial length, respec- latter tract occupying approximately 52% of
786 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Figs. 7-9. Trichogramma iimerus. male. 7, Dorsal view of genital capsule; scale bar = 50 |JLm. 8, Ventral
view ofgenital capsule; scale bar = 50 fjim. 9. Ventral view ofapical distance; scale bar = 20 [xm.
VOLUME 107, NUMBER 4 787
V'vWW^.'vV-
10 11
13
Figs. 10—!3. Trichogramma umerus. 10, Dorsal and ventral view ofmale genital capsule. 1 1, Forewing. 12.
Antenna. 13, Hindwing. Scale bars = 0.05 |xm.
distance from hamuli to wing apex. Scutel- 0.26 ± 0.01 entire genital length (GL); api-
lum with anterior pair of setae measuring cal width (AW) 0.60 ± 0.03 genital width
86-91% posterior pair (n = 2). (GW); dorsal aperture length (DAL) 0.56 ±
Male: Flagellum length (FL) 0.15-0.18 0.02 GL; dorsal lamina (DLA) originating
mm, 1.92-2.42X longer than scape, FL posterior to middle of GL, moderately
6.85 ± 0.44X greater than flagellum width notched at base with moderately developed
(FW), FL 1.16 ± 0.09X HTL; flagelliform shoulders, not reaching sides of GC; sides
setae long, 3.0 ± 0.12X greater than FW; of DLA gradually narrowing posteriorly to
without unsocketed setae; basiconic peg form a sublinguiform posterior extension,
sensilla (BPS) relatively small, slightly in- distinctly acuminate at apex, with width ap-
flated, formula l(2)-2-2-0-l-l, terminal proximately equal to that of aedeagus at in-
placoid sensilla (PLS) with apical 0.09- tervolsellar process (IVP) level; DLA 1.38
0.16 (n = 6) extending beyond flagellum ± 0.05 as long as wide 0.39 ± 0.02 GL.
apex. occupying 0.42-0.57 AD; volsellae (VS)
Genital capsule (GC) 0.33 ± 0.01 as slightly bowed occupying 0.42-0.57 AD;
wide as long; sides not constricted at level IVP elongate, narrowing apically toward
of intervolsellar process (IVP); parameres pointed apex, occupying 0.30-0.43 AD;
(PM) relatively straight, slightly convergent ventral processes (VP) not obviously pro-
at apex; apical distance (AD) measuring tuberant, positioned immediately basal to
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788 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
IVP; VR occupying 0.24-0.34 basal dis- although a few extra tandem repeats were
tance (BD). Aedeagus length (AL) approx- found in the T. umerus sequence. In this
imately equal to GL, attaining 0.77 ± 0.05 section there appeared to be higher com-
HTL; apodemes about 0.49 AL. patibility in T. minutum than in T. pretios-
Female: Antenna with and 2 BPS on um as more base pairs were shared. How-
1
first funicular segment (Fl) and second fu- ever, the final one-third sequence alignment
nicular segment (F2), respectively. Ovipos- could not be matched in either T. minutum
itor lengt—h (OL) 0.82-0.85 HTL. or T. pretiosum as there was a large exten-
Types. Holotype 6: JAPAN. Okinawa sion of ca. 100 base pairs in T. umerus.
Prefecture: Ishigaki Island; 13 March 1997; Acknowledgments
P. xylostella; Y. Narai and N. Kajitani. We thank John Pinto and Gary Platner
Paratypes: 7 S and 3 9 including allotype for their suggestions and comments. We
9, same data a—s holotype. also thank Fujio Aoyama for providing Tri-
Etymology. Derived from the Latin
chogramma specimens reared in his labo-
word umerus meaning shoulder, referring to ratory at the Shimane Agricultural Experi-
DLA
the distinct shoulders of the present ment Station. Laurel Taylor provided pho-
in the type series, used as a noun in appo- tomicrographs. This work was partially
sition. funded through a JSPS fellowship award to
Remarks. Trichograimna umerus keys JYH.
to couplet 74' in Pinto's (1999) key to the
Literature Cited
North American Trichogramma which ter-
minates with T. pretiosum. These species Ishii, T 1938. On the species of Trichogramma and
are remarkably similar and even share the theirecology in Japan. Oyo-Dobutusugaku-Zasshi
10: 139-141 [in Japanese].
characteristic ofhaving a poorly sclerotized . 1941. The species of Trichogramma in Japan
posterior extension of the dorsal lamina. with descriptions oftwo new species. Kontyu 14:
However, T. umerus has a much different 169-176.
ITS-2 sequence (see below) and these spe- NCBI handbook [Internet]. Bethesda (MD): National
Library of Medicine (US), National Center for
cies can be separated by characters dis-
Biotechnology Information; 2002 Oct. Available
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DNA sequence. The 526 bp ITS-2 fcgi?db = Books
DNA sequence for T. umerus has been de- Pinto, J. D. 1999 [1998]. Systematics of the North
posited in the NCBI Database (accession American species of Trichogramma Westwood
(Hymenoptera: Trichogrammatidae). Memoirs of
AY518694). We performed pair-wise com- the Entomological Society ofWashington No. 22,
parisons with both T. minutum (NCBI 287 pp.
#AF408658) and T. pretiosum (NCBI Platner, G. R., R. K. Velten, M. Planoutene, and J. D.
#AF082822) to determine their sequence Pinto.1999. Slide-mountingtechniquesforTricho-
gramma (Trichogrammatidae) and other minute
compatibility. The T. minutum 420 bp se- parasitic Hymenoptera. Entomological News 110:
quence was 59% compatible to that of T. 56-64.
umerus while 400 bp T. pretiosum sequence Taylor, L., N. Yashiro, Y. Hirose, and J. Y. Honda. In
was 53% compatible. Interestingly, in T. press. A new species of Trichogramma (Hyme-
noptera: Trichogrammatidae) parasitic on Ivera
minutum and T. pretiosum, there was a high auripes(Butler) (Lepidoptera: Lymantriidae)from
degree of compatibility at the very begin- Hokkaido. Japan. Annals of the Entomological
ning and middle of the sequence alignment Society ofAmerica.