A NEW SPECIES OF APHELINUS (HYMENOPTERA : APHELINIDAE) THAT PARASITIZES THE SPIREA APHID, APHIS SPIRAECOLA PATCH (HOMOPTERA : APHIDIDAE)

5 Pages·1995·2.2 MB·

PROC. ENTOMOL. SOC. WASH.
97(1), 1995, pp. 17-21
A NEW SPECIES OF APHELINUS(HYMENOPTERA: APHELINIDAE)
THAT PARASITIZES THE SPIREA APHID, APHIS SPIRAECOLA
PATCH (HOMOPTERA: APHIDIDAE)
Gregory A. Evans, Michael E. Schauff, Moh Leng Kok-Yokomi,
AND Raymond K. Yokomi
(GAE) University of Florida, Entomology and Nematology Department, Gainesville,
Florida 32611; (MES) Systematic Entomology Laboratory, USDA-ARS, PSI, % U.S.
National Museum of Natural History, NHB 168, Washington, D.C. 20560; (MLK-Y)
University ofFlorida, IFAS, Central Florida Research and Education Center, Leesburg,
Rorida 34748; (RKY) USDA, ARS, Horticultural Research Laboratory, 2120 Camden
Road, Orlando, Florida 32803.
—A
Abstract. new speciesofan aphid parasitoid,AphelinusspiraecolaeEvansand SchaufF
(Hymenoptera: Aphelinidae) is described and figured. This species is parasitic on the
spirea aphid. Aphis spiraecola Patch, and is being investigated for possible use in a bio-
logical control program against the spirea aphid and other citrus aphids including the
brown citrus aphid, Toxoptera citricida (Kirkaldy). The new species is very similar to
Aphelinus gossypii and characters to differentiate it from related species are given.
Key Words: Parasitoid, biological control, citrus, citrus tristeza virus
During 1992, collections of aphid para- find control measures that would suppress
sitoids from citrus were made in four prov- theaphid population and mitigate thedam-
inces of the People's Republic of China age.
namely, Sichuan, Hunan, Fujian, and The species described in this paper was
Guangdong. Some ofthe emerging parasit- originally believed to be Aphelinus gossypii
oids collected from the Guangzhou area Timberlake, a common, widespread para-
(Guangdong Province) were brought to site of the melon or cotton aphid. Aphis
Floridaforstudyaspotentialbiologicalcon- gossypii Glover, and related aphids. How-
trol agents ofcitrus aphids. ever, investigation ofthe biologyofthe spe-
Thisresearchwasundertaken becausethe cies from China revealed differences be-
brown citrus aphid, Toxoptera citricida tween it and that of.4. gossypiiincluding its
(Kirkaldy),themostefficientvectorofcitrus ability to attack the spirea aphid. Aphisspi-
tristeza virus has spread throughout the Ca- raecola Patch (Yokomi et al. 1993). Further
ribbean Basinexceptthe Bahamas(Yokomi examination revealed characters that were
et al. 1994) and is likely to be introduced different from those ofA. gossypii and we
into the continental U.S. in the foreseeable are, therefore, proposinganewspeciesname
future. Thisaphidgenerallyattacksonlycit- for this taxon.
rus and citrus relatives and is thought to be Theimportance ofthisnewspeciesisdue
native to Asia where citrus originated. Be- to its potential as a biological control agent
causetheaphidhaspotential tocause major ofthe spirea aphid which has few effective
damage to citrus, research is under way to parasitoids in the United States(Cole 1925,
18 PROCEEDINGSOFTHE ENTOMOLOGICALSOCIETY OFWASHINGTON
Figs. 1-7. ApheUnusspiraccolae. femaleexcept Figs. 6, 7: 1, fore wing, disksetaeexcludedand stigmal vein
magnified. 2, thorax. 3, antenna. 4, gaster(venter)and hind leg. 5, mandible. 6, antenna. 7, aedeagus.
VOLUME 97, NUMBER 19
Miller 1929, Tang et al. 1994). The spirea 2pairsofblacksetae, placoidsensillaesmall
aphid is abundant on citrus worldwide and and widely separated, with pale, diamond-
has a wide host range. It transmits citrus shape markings around each; endophragma
tristeza virus (Yokomi and Gamsey 1987), short, about 0.7 times as long as the length
as well as some potyviruses (Adlerz 1987). ofthethorax;tibialspurofmiddlelegslight-
ly shorter than corresponding basitarsus;
Aphelinus spiraecolae hind tibia with 7 conspicuous conical setae
Evans and Schauff, New Species at apex, tibial spur ofleg III about one-half
Figs. 1-7 as long as corresponding basitarsus. Fore
Diagnosis.—Headandthoraxdarkbrown; wing (Fig. 1) broad, more than 2 times as
legs yellow except dark brown coxae and long as wide (0.8:0.36 mm); costal cell 1.2
hind tibiae; gaster dark brown with yellow- times longer than marginal vein and with
ish base; Fl and F2 broader than long, F3 20-25 ventral setae in 2 rows and 11-13
quadrate; costal cell offore wing with two dorsal setae; submarginal vein with 5-6 se-
linesofventral setae, area proximal to linea tae; marginal vein with 9 setae along the
calva bordered by one complete row of 13- margin,allabout 1.5 timeslongerthanwidth
16 setae and one incomplete row of 2-5 of marginal vein; basal cell bare; stigmal
setae. vein short with stigma rounded; area prox-
mm
Female: Length, 0.95-1.2 (Holo- imal to linea calva bordered by one com-
type, 0.98 mm). Color: Head and thorax pleterowof1 1-15 setaeandoneincomplete
dark brown, legs yellow except dark brown rowof 1-5 setae; marginal fringe very short,
coxae and hind tibiae; gaster dark brown less than 0.05 times as wide as fore wing
with base (terga I) yellowish; endophragma disc; ciliation dense after the linea calva.
fuscous; third valvulae palewith darkbrown Gaster(Fig. 4)longerthanthorax(0.56:0.35
lateralmargins;antennaelightbrown;wings mm); ovipositor(0.35 mm)insertedatmid-
hyaline. Structure: Head dorsum about as dle ofgaster, only slightly exerted distally,
broad as thorax; mandibles bidentate (Fig. longer than hind tibia (0.29 mm) and mid
5) with an internal tooth, a blunt middle tibia (0.21 mm); third valvulae (0.12 mm)
tooth and a truncation; lateral ocellus sep- one-third the length ofentire ovipositor.
arated from eye margin by one ocellus di- Male: Length (0.88-0.92 mm): Similar
ameter; occiput reticulate. Antenna (Fig. 3) to female except central portion offemur II
withshortradicle; scapeabout4to 5.5 times and tibia II slightly infuscate; radicle, scape
aslongasbroad; pedicel(ventrallength)less and pedicel brown (Fig. 6); scape with 3
than 2 times its width; Fl annuliform, with round sensoria and club with 2 linear sen-
ventral margin longer than dorsal margin; sillae; abdomen tapering distally; aedeagus
F2 broader than long, as long as Fl; F3 as shown in Fig. 7.
—
quadrate, about 2 times longerthan F2 with Material examined. Holotype female,
one linear sensillum; club 2.4 times longer Fushan City, Guangdong Province, P.R.
than broad, about 3 times longer than F3 China, VII 1992, ex Aphis spiraecola, R.
with 6-7 linear sensillae and 7-8 papillae. Yokomi, deposited in the Institute of Zo-
Thorax (Fig. 2) with fine reticulations; mid- ology, Academy of Sinica, Beijing, P.R.
lobe of mesoscutum with two pairs of pri- China. Paratypes (19 99, 11 <5<5) with same
mary setae andapproximately 40 setae, pri- data as holotype. Paratypes deposited in:
mary setae MC (posterior central) short, as U.S. National Museum ofNatural History,
ML
long as (anterior lateral) setae, and ax- Washington, D.C.; Florida State Collection
illar setae (AS), reaching base ofSCI setae; of Arthropods, Gainesville, Florida; The
each sidelobewith 2-3 setae; scutellum with Natural History Museum, London, En-
20 PROCEEDINGS OFTHE ENTOMOLOGICALSOCIETY OFWASHINGTON
gland; Canadian National Collection, Ot- Aphelinus spiraecolae is also similar to
tawa and the Collection of M. Hayat, Ali- Aphelinuschaonia Walker. This species has
garh, India. a wide distribution and host range. It was
Known distribution.—Guangdong Prov- introduced into California by Flanders and
ince, P.R. China. Fisher(1959)from SouthChinaforthecon-
CommenXs.—Aphelinus spiraecolae is trol oftheblackcitrusaphid, Toxopteraau-
placed in the Aphelinus subgenus ofthe ge- rantii, and propagated in the laboratory on
nus Aphelinus as defined by Hayat (1990). thespireaaphid. Thesetwo speciescan usu-
This species is similar in body color and ally be easily distinguished from each other
fore wing ciliation to species placed by Ze- by the color ofthe legs. Normally, the fem-
haviand Rosen (1988)in theAphelinus mali oraoftheforeand middlelegsofA. chaonia
group {Aphelinus campestris Jasnosh, A. are dark brown. However, the legs are yel-
gossypii Timberlake, A. mali (Haldeman), lowish in the light form of.4. chaonia. Nev-
A. paramali Zehavi & Rosen, and A. pro- ertheless, A. chaonia can be distinguished
ciphiliCarver). However, it differs from the by the greater number ofsetae (more than
species in thisgroup by the colorofthelegs. 20) along the proximal border ofthe linea
The femora ofthe middle legs ofall ofthe calva ofthe fore wing (less than 20 setae in
maligroup speciesaredarkbrown. The legs spiraecolae) and the dark base ofthe gaster
oftheA. spiraecolaefemale areentirely yel- (base ofgaster yellow in spiraecolae).
low except for its dark brown coxae and
Acknowledgments
hind tibia. While differences in body color
may be useful in discriminating different We thank Q. Tang (USDA, ARS, Hor-
Aphelinus species, these differences alone ticultural Research Laboratory, Orlando,
may not always provide conclusive evi- Florida; Visiting Scientist from the Biolog-
dence to distinguish different species. Jans- ical Control Research Institute, Fujian Ag-
sen (1961) and Michel (1969) reported con- riculturalCollege, Fuzhou, FujianProvince,
siderable intraspecific variation in the color 350002, P.R. China)fortechnicalassistance
ofthe body (and legs) ofAphelinus asychis and who first noted these specific morpho-
Walker (= semiflavus (Howard)) and A. logical characters during his studies on the
chaonia Walker, respectively. Given this biology ofthis species. We are indebted to
variation and the fact that species groups Dr. LimhoutNong(Florida Dept. Agric. and
are not welljustified norwidely used in this Cons. Serv., Div. Plant Ind., Gainesville,
genus, we are not assigning A. spiraecolae Florida) for maintaining the parasitoid col-
to a species group at this time. ony in a containment facility. Wegratefully
Of the species mentioned above, Aphe- acknowledge the Ministry of Agriculture,
linus spiraecolae is most similar to A. gos- Beijing, P.R. China, for kind support and
sypii (Timberlake) in coloration, shape and local arrangements that allowed us to con-
ciliation of the fore wing, and antennal ductthesurveyinChinafornaturalenemies
structure. However, in A. gossypii the fem- ofcitrus aphids; the Florida Citrus Produc-
ora and tibiae of the fore and middle legs tion Research Council for its financial sup-
and basitarsi ofthe hind legs offemales are port and the Office ofInternational Coop-
MC
dark brown. The setae are elongate, eration and Development, Research and
reaching the placoid sensillae (shorter and Scientific Exchange Division, USDA,
not reaching placoids in spiraecolae); and Washington, D.C. for kind support and co-
the setae along the marginal vein are about operation. We thank Drs. M. Hayat (Ali-
2 times as longas the width ofthe marginal garh Muslim University), and H. Browning
vein (setae 1.5 times longer than width of (UniversityofFlorida, Citrus Research and
marginal vein in spiraecolae). Education Center, Lake Alfred, Florida) for
VOLUME 97. NUMBER 1 21
theirreviewofandcommentsregardingthis Patch. Florida Agricultural Experiment Station
manuscript. Bulletin 203: 431-476.
Tang, Y. Q., R. K. Yokomi, and R. J. Gagne. 1994.
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