Psydrothrips luteolus, new species, from Hawai and notes on P. Kewi (Thysanoptera: Thripidae)

6 Pages·1994·2 MB·

by  S Nakahara

PROC. ENTOMOL. SOC. WASH.
96(1). 1994. pp. 156-161
PSYDROTHRIPS LUTEOLUS, NEW SPECIES, FROM HAWAII AND
NOTES ON KEWI (THYSANOPTERA: THRIPIDAE)
P.
SuEO Nakahar-a and Dick Tsuda
(SN) Systematic Entomology Laboratory, PSI, Agricultural Research Service, USDA,
10300 Baltimore Avenue, Beltsville, Maryland 20705-2350: (DT) Department ofEnto-
mology, University ofHawaii at Manoa, Honolulu, Hawaii 96822.
Abstract.—Psydrolhrips luteolus, new species, damages Dieffenbachia sp. and other
Araceae in Hawaii. The adult female and male and second-instar larva are described and
illustrated. Additional descriptions are provided for P. kewi Palmer and Mound, the type
species ofthe genus, and its origin is discussed.
Key Words: Psydrothrips. luteolus. kewi. adults, larva, Dieffenbachia, Araceae, Hawaii
Psydrolhrips kewi Palmer and Mound immature instars and adults were observed
(1985), the type species ofa monotypic ge- bythejuniorauthorandarediscussedunder
nus, was first noticed in 1982 when it se- "Habits."
verelydamaged leavesofPhilodendronspp. Measurements are in microns except for
in a glasshouse at Kew, England. The in- body length which is in millimeters. Mea-
fested philodendrons were imported from surements of holotype are given first fol-
Brazil, Mexico and Trinidad indicatingthat lowed by those of the female paratypes in
P. kewiis ofneotropical origin. However, a parentheses ( ) unless otherwise indicated.
collection record ofP. kewi from the Neo- LJSNM is an acronym for the LJnited States
tropics was not available until recently. National Museum of Natural History,
While examining unidentified material of Washington, D.C.
USNM
another genus in the Thysanoptera
Collection in 1992. a specimen of P. kewi Psydrothrips luteolus. New Species
—
was discovered b> the senior author. This Female(macroptera). Head(Fig. 1)pale
specimen was intercepted on philodendron yellow with eyes grayish brown except om-
canesfrom Tamazunchale, San Luis Potosi, matidia colorless, small grayish brown area
Mexico at agricultural quarantine in 1952 extending posteriorly from eye between po-
atLaredo,Texas.Thus,theinfestion inKew sitions ofPOiii and POiv setae (Fig. 1, C);
may have been introduced on philoden- ocellar crescent red; pronotum yellow with
drons imported from Mexico, and it may a posterolateral light grayish brown area on
not occur in Brazil or Trinidad. eachside(Fig. 2,C): pterothoraxpaleyellow
The second Psydrothrips taxon, luteolus. with preepistemum brown; legs yellow; se-
new species, was discovered in Honolulu. tae light brown or yellow; forewing grayish
Hawaii, in July of 1991 on Dieffenbachia brown, paler distally. a subbasal pale area
sp. and was subsequently found on other posteriorto forevein, scalecompletelygray-
araceaeous hosts in several localities in the ish brown; hindwing with median longitu-
city. It damages the young leaves of these dinal gra>ish brown stripe, scale grayish
hosts. The feedingdamageand habitsofthe brown. AntennalsegmentsI and II lightyel-
VOLUME 96. NUMBER 1 157
low. III yellow with distal part grayish part without sculpturing and posterior part
brown, IV yellowon basal -A,grayish brown weakly sculptured; anteromedial sensilla
on distal 'A, V yellow on basal 'A, grayish absent; submedial setae short, far anterior
brown on distal 'A, VI grayish brown with to posterior margin. Mesothoracic sternal
yellowish brown or yellow area distal to furca with poorly developed spinula. Meta-
grayish brown base, VII-IX grayish brown. notum: Completely reticulated polygonally;
Antenna (Fig. 3): Segments III-IX elon- median setae posterior ofanterior margin;
gate: III constricted at base, with irregular other sensilla absent. Metathoracic sternal
innerand outer margins, 3.35 to 3.75 times furca with well developed spinula; inter-
as long as wide (Fig. 3, A); segments V and coxal process with subtruncate apex.
VI subequal in length; III and IV with Forewing: Straight, pointed at apex; 26-
U-shaped trichomes, 30 (30-37) long, inner 28 (25-28) costal setae, those at midlength
sense cone on VI 54 (54) long (Fig. 3, B), shorter than width ofwing; 24-26 (21-28)
extending to distal 'A ofVIII. straight, anterior fringecilia; posterior fringe
Head {Fig. 1): Wider than long, slightly cilia wavy; forevein with 9 (8-10) setae in
produced anterior to eyes, apex of vertex proximal 'A, 3 setae in distal 'A, hindvein
between base of antennae rather wide, in- with 11 (9-14) setae; scale with usually 5
terantennal processtruncate, 'A to% aswide (4-6) marginal setae and 1 discal seta.
as antennal segment I. Eyes slightly longer Abdomen: Median setae on tergites far
than occiput, interoculardistance about 1.5 apart, reduced on tergite I, gradually longer
times wider than width of eye. Cheeks posteriorly, well developed on tergite VIII.
slightlyconvering posteriorly, either straight separated by at least twice its length; tergite
orslightlyconcave. Occiput with transverse II with 3 lateral setae. Sculpturelinesabsent
anastomosing sculpture. Fore ocellus al- from median area on tergites I-V, present
most aligned with anterior margin ofeyes, mediallyonVI-VIII; numerousmicrotrich-
17-22 wide; hind ocelli separated by 1.5 to ia on sculpture lines and on posterior mar-
2.0 timesthe diameteroffore ocellus. Ocel- gins on lateral 'A to 'A oftergites I-VII (Fig.
lar setae I short, anterior of fore ocellus; 4, B), anterior and mesal ones short, longer
ocellar setae II short, anterolaterad of fore laterally and posteriorly. Posteromarginal
ocellusand near mesal margin ofeyes; ocel- comb on VIII complete, with 38 (37-50)
lar setae III well developed, laterad offore close-set microtrichia, longest 20-24 (Fig.
ocellus (Fig. 1, A). Four pairs ofpostocular 4, A). Tergite IX longerthan X, with 2 pairs
setae (PO), POi-iii setae subequal in length ofsensilla; B1-B3 setae longer than tergite
(Fig. 1, B). aligned longitudinally, POiv X; tergite X without dorsal split. Pleuroter-
shorter and laterad to POiii. Mouthcone gites without accessory setae, with micro-
broadly conical, rounded apically, extend- trichia on sculpture lines, and microtrichia
ing between prothoracic coxae. or teeth on posterior margin; pleurostemite
Pronotum (Fig. 2): Wider than long, with microtrichia on sculpture lines, and
shorter than head, weakly sculptured; nor- teeth on posterior margin. Stemites II-VII
mally with a short, irregular longitudinal with accessory setae in irregular row; an-
median line on disc. Discal setae short, 35 teromedial setaeabsent from stemiteI; ster-
(28-35) present; 1 pair of posteroangular nites II-VII with 3 pairs ofposteromarginal
setae developed, % to % as long as notum, setae, median pair on stemite VII on pos-
usually between 'A to % as long (Fig. 2, A); terior margin.
posteromarginal setae 2 pairs, median pair Male (macroptera).—Similartofemale in
longest (Fig. 2, B). Fema complete, with 1 color and most morphological characters,
pairofshortsetae. Mesonotum: Transverse, but smaller. Abdominal tergite VIII with
anastomosing sculpture medially, anterior well developed, complete posteromarginal
158 PROCEEDINGS OFTHE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Figs. 1-6. Psydrothrips haeolus (scale for figures = 0.1 mm). 1. Female head: .A) ocellar setae III; B) POiii
seta; C) brown area. 2. Female pronotum: .\) posteroangular seta; B) posteromarginal seta; C) grayish brown
area. 3. Female antenna: .\) segment III; B) sense cone on segment VI. 4. Female abdominal tergites VII and
VIII: \) posteromarginal comb; B) microtnchia. 5, Male abdommal tergites IX and X: A) posteromarginal
comb; B) Bl seta; C) B2 seta; D) dorsal seta; E) posterolateral seta; F) sensillum. 6, Male abdominal stemites
II and III; A) glandulararea.
comb (Fig. 5. A). Tergite IX with median B2 setae; dorsal setae bristlelike, laterad of
notch on posterior margin; Bl and B2 setae B1 setae(Fig. 5, D); posterolateralsetaestout
short, stout, spinehke (Fig. 5. B and C); Bl (Fig. 5. E). a thick, shorter setajust anterior
setae anteriorand closer to each other than ofposterolateral seta; singlebristlelikesetae
VOLUME 96, NUMBER I 159
anterior to posterolateral setae; a sensillum teromarginal setae 20long; ontergite IX Dl
anterior or anterolaterad of each B2 seta, setae 82-89 long. 31 setae 22 long. 6 wide,
another pair between Dl setae and anterior B2 setae 30-32 long, 5 wide; long postero-
margin (Fig. 5, F). Stemites II-VIII with lateral setae 64 long. 6 wide, shorter pos-
accessory setae in single row, median, oval terolateral setae 40 long, 3 to 4 wide; bris-
gland in intersegmental membrane between tlelike setae anterior of posterolateral seta
stemites II and III, 24 long, 27 wide (Fig. 37^2 long; midlateral seta 50 long.
6. A). Second-instar larva: Body white with
Measurements of holotype and female light reddish internal pigment, eye with red
paratypes: Body length 1,57 (1.48-1.59) pigment. Antennal segment I light grayish
mm
(distended). Antenna: Total length: 337 yellow on basal 'A. membranous, white dis-
(323-355); length and width of segment I tally; II light grayish yellow, apically mem-
24 (22-24), 33 (32-35); II 37 (35-42), 30 branous,white; IIIgray,basallyandapically
(30); III 62 (57-64), 17(17); IV 54 (52-59), membranous, white; IV-VII gray with in-
17 (17-20); V 47 (44-52), 17 (17-18); VI tersegmentalpartsmembranous, white. An-
47 (44-52). 17 (17-18); VII 22 (20-22). 12 teromedial gray band extending dorsoven-
(12-13); VIII 22 (22), 10 (10); IX 22 (22- trally between antennal bases. Tarsi, tibiae
23), 6 (5-7). and base offemora gray. Abdominal tergite
Length of head from interantennal pro- IXwithgrayishyellowbandextendingfrom
cess 165 (158-165). from anterior of eyes posteriormargin tobetweendorsalsetaeand
141 (136-157). widthat eyes 188(185-195), sensilla (Fig. 7, A); tergite X grayish yellow
at cheeks 173 (178-188). Pronotum 121 to anterior ofsensilla (Fig. 7. D).
(103-128) long, 285 (190-203) wide. Fore- Antennal segment IV with microtrichia
wing 728-770 (701-839) long, 47 (47-57) on annulations, other segments lack micro-
wideat midlength. Abdominal tergite IX 86 trichia; segment VII 1.5 to 2.0 times longer
(86-100) long, tergite X 74 (74-79) long. than segment VI; outer sense cone on VI
Length ofsetae: Ocellar setae I (17-22). se- longer than segment VII, Head with long
tae II (22-24), setae III 37 (40-54); POi se- D2 seta, Dl and D2 setae pointed apically,
tae 32 (32), POii 27 (30-32), POiii 24 (24- D3 blunt apically. D4 expanded apically,
30), POiv 12 (15-17); pronotal posteroan- D5 short, pointed apically, Pronotum with
gular setae 54-59 (50-64); median postero- dorsal setae pointed except apex ofD6 ex-
marginal setae 22 (24-30); metanotal me- panded orblunt. Legswith 1 longexpanded
dian setae 22-24 (24-27); median setae on seta on tarsi, fore- and hindtibiae each with
abdominal tergite VIII 37 (37-44); 31 setae 4 dorsal setae with expanded apices, mid-
on tergite IX 101 (101-1 11), 32 setae 114 tibia with 5 dorsal setae with expanded api-
(114-121),33setae 121 (109-1 17); 31 setae ces, femora each with 4 expanded setae,
on tergite X 109 (99-1 1 1). 32 setae 99 (96- coxae each with 1 seta with expanded apex.
109). Abdominal tergites I-VI with Dl and D2
Measurements of male paratype: Body setae normally slightly expanded apically
mm
1,27 long (distended). Antenna: Total with a point and D3 setae on III-VI with
length 290; length and width ( ) ofsegment expandedapices(Fig. 8. A, 3andC);tergites
I 22 (30). II 35 (27). Ill 52 (17), IV 44 (17), VIIandVIIIwith D1 setaenormallyslightly
V 40 (17), VI 40 (17). VII 17 (12). VIII 20 expandedapicallywithapointand D2 setae
(10), IX 20 (7). Length ofhead from inter- with expanded apices (Fig. 8, A and 3), D3
antennal process 124, from anterior ofeyes setae on VII with expanded apices (Fig. 8,
121, width at eyes 161, at cheeks 148. Pro- C) and those on VIII with pointed apices;
notum 99 long. 173 wide. Forewing 644 IX with Dl setae normally blunt apically
long, 44 wide at midlength. Pronotal pos- (Fig. 7, 3), D2 setae expanded apically (Fig.
teroangular setae 44-50 long, median pos- 7. C); dorsal setae on tergite X slender, bris-
160 PROCEEDINGS OFTHE ENTOMOLOGICAL SOCIETY OF WASHINGTON
VI
VII
B C
8
10
Ay
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Figs. 7-11. Second-instarlarva ofPsydinthnps luteolus(scale for figures = 0.1 mm). 7, Abdominal tergites
IX and X: A) sclerotized band; B) Dl seta; C) D2 seta; D) sensilla. 8, Abdommal tergites VI and VII: A) Dl
seta; B) D2 seta; C) D3 seta. 9, Abdominal tergite V: A) plaques. 10, Mesothoracic spiracle. 1 1, Spiracle on
abdominal segment VIII.
tielike; ventral setae slender and tapered femaleand 3 maleparatypes; Hawaii,Oahu,
apically. Abdominal tergite IX without pos- AieaHts.,unfurled\eafofDieffenhachiasp.,
teromarginal teeth, sensilla slightly farther 13-V-92, W. Nayamine. Hawaii,Oahu, Ho-
apart than distance between Dl setae (Fig. nolulu: St. Louis Hts., 1 female and 1 male
7). Mesothoracicspiraclewith 1 roworwith paratypes, unfurled leaves ofDieffenbachia
partial second row of cells around orifice sp., 1-VII-91, M. Nakamota; ManoaValley,
(Fig. 10); abdominal spiracle on segment II 3 femaleand4 maleparatypes, unfurledleaf
small, circular, with 3 cells, spiracle on seg- of wild Epipremmim pinnatum (L.) Engl.,
ment VIII slightly larger, with 4-5 cells(Fig. 9-1-92, D. M. Tsuda; University ofHawaii
1 1). Plaques oval, without microtrichia. at Campus, 6 female and 1 male paratypes, 10
most with a mere point, in about 8 rows on larvae, Epipremmim pinnatum. 2 female
tergite V (Fig. 9), those on stemite about paratypes, Syngoniumpodophyllum Schott.,
same size as dorsal ones, in fused spinulose I female paratype, Philodendron sp., 8-V-
sections ofvarying widths on tergite IX. 92, D. M. Tsuda. Holotype and paratypes
Materialexamined: Holotypefemale, 11 depositedin USNM; paratypesdepositedin
VOLUME NUMBER
96, 1 161
Bishop Museum, Honolulu, Hawaii; Cali- the Neotropics because it closely resembles
fornia Dept. ofFood and Agriculture, Sac- P. kewi and has similar host preferences.
ramento; Florida State Collection of Ar-
thropods, Gainesville; The Natural History Psydrothrips kewi Palmer and Mound
Museum, London, United Kingdom; and The following morphological and color
Forschungsinstitut und Naturmuseum characterswerenotdiscussed in theoriginal
Senckenberg, Frankfurt am Main, Germa- descriptionofP. Arewvandareamended here
ny. to provide a more accurate concept of the
Hosts: Diejfenbachia sp., Epipremmtm species: Antennal segments I and 11 brown
pinnatum (L.) Engl., Philodendron sp.. and with apexofII yellow. III yellowwith distal
Syngonium podophyllum Schott. part grayish brown, basal '/: of IV yellow
Etymology: Specific epithet, Latin "lu- anddistal Vibrown, basal VjofVyellowand
teolus" (yellowish), characterizes the pre- rest brown, VI-IX brown. Forewing uni-
dominantly yellow body ofthis species. formly brown with a subbasal pale area
Habits: This cryptic, fast moving thrips present; scale completely brown. Pronotal
attacks young emerging leaves. Feeding posteroangular setae 35-50 long; postero-
damage is quite obvious. An infested ter- marginal setae 3 pairs, occasionally total of
minal (young unfurled leaf) becomes stunt- 5 setae present. Mesonotum sculptured me-
ed and malformed, with the outer surface dially and posteriorly, unsculptured ante-
blackened. Larvae and adults hide and feed riorly; anteromedial sensilla absent. Ab-
within the narrow space between the base dominal tergite II with 3 lateral setae on
ofthe leafstem (younger leaves) and trunk each side; abdominal stemite I without an-
(vine), and more commonly between the teromedial setae, sternite II with 3 pairs of
loose layers of the young unfurled leaves. setae on posterior margin.
The mature larvae and pupae hide in the
Acknowledgments
leafaxils ofolder leaves.
Comments: Psydrothrips hiteolus adults We thank the following colleagues for re-
differ from P. kewi by yellow antenna! seg- viewing the manuscript and for their useful
ments I-IL almost completely yellow head, suggestions; R. J. Beshear, University of
and longer pronotal posteroangular setae, Georgia, Griffin; C. L. Cole, Texas Agri-
59-64 long. Conversely, P. kewi has brown cultural Extension Service, Bryan; R. L.
antennal segments I-IL head yellow medi- Smiley, Systematic Entomology Labora-
ally and brown anteriorly and submargin- tory, Beltsville, and D. R. Smith, same lab-
ally through the eyes to the posterior mar- oratory, Washington, D.C. We also thank
gin, and shorter pronotal posteroangular L. A. Mound, The Natural History Muse-
setae shorter, 35-50 long. um, London, for providing paratypes ofP.
The distribution ofapically pointed and kewi for our study. The illustrations were
expanded dorsal setae, absence ofpostero- preparedby Linda H. Lawrence, Systematic
marginal teeth from abdominal tergite IX, Entomology Laboratory.
sclerotization on tergites IX and X, and ab-
Literature Cited
sence of microtrichia from antennal seg-
ment III distinguish the second-instarlarva Palmer, J. M. and L. A. Mound. 1985. New world
ofP. hiteolusfrom thoseofotherthrips spe- Thripidae (Thysanoptera) with nine-segmented
cies in Hawaii. antennae. Zoological Journal ofthe Lmnean So-
ciety 84: 181-194.
Although the origin of P. luteolus is un-
known, it apparently was introduced from