Table Of ContentPROC. ENTOMOL. SOC. WASH.
104(4). 2002. pp. 918-927
PENTAMYZUS HILLE RIS LAMBERS, A NEOTROPICAL GENUS OF THE
TRIBE MACROSIPHINI (HEMIPTERA: APHIDIDAE: APHIDINAE), WITH
THE DESCRIPTION OF A NEW SPECIES
J. M. NiETO Nafria, M. p. Mier Durante, and J. Ortego
(JMNN, MPMD) Departamento de Biologia Animal. Universidad de Leon, E-24071
Leon, Spain, (e-mail: [email protected]); (JO) Instituto de Sanidad y Calidad Agrope-
cuaria de Mendoza. Boulogne sur Mer, 3050.5500 Mendoza, Argentina.
—
Abstract. Pentamyzus fueguinus, n. sp., is described and two little-known South
American species ofPentamyzus, P. tenuis and P. acaenae, are studied from aphids caught
in Tierra del Fuego (Argentina). Considering that Pentamyzus is one of the few genera
of Macrosiphini in the Neotropical Region, we present several hypothesis about its evo-
lution in the subcontinent.
—
Resumen. A partir de pulgones capturados en Tierra del Fuego (Argentina) se describe
Pentamyzusfueguinus n. sp. y se estudian otras dos especies sudamericanas poco cono-
cidas: P. tenuis y P. acaenae. Aprovechando que Pentamyzus es uno de los pocos generos
de Macrosiphini con representacion neotropical se analizan varias hipotesis sobre su his-
toria evolutiva en el subcontinente.
Key Words: Pentamyzus, Aphididae, Macrosiphini, aphid evolution, new species, Tierra
del Fuego, Argentina
Macrosiphini (Aphidinae) is the richest species). Utamphorophora peruviana (Es-
tribe both in species and genera in the fam- sig 1953), Macrosiphum salviae Bartholo-
ily Aphididae (Remaudiere and Remaudiere mew 1932, and Wahlgreniella australis
1997, Eastop 1998) and it is very difficult Delfino 1981 may also be native. Penta-
to subdivide it into subtribes "because spe- myzus is the only genus of these with spe-
ciation in a great scale has taken place dur- cies living on Poaceae or Rosaceae, Vv'hich
ing a rather short time rather recently" are very important plant families in the spe-
(Heie 1992). The tribe Macrosiphini is ciation of Aphidinae (Heie 1996, von Doh-
poorly represented in the Neotropical Re- len and Moran 2000).
gion and most ofits species recorded in this Pentamyzus includes fourknown species:
region are allochthonous (Smith and Cer- P. acaenae (Schouteden 1904) from Tierra
meli 1979, Nieto Nafria et al. 1994). Au- del Fuego (Argentina); the type species P.
tochthonous Neotropical species belong to graminis Hille Ris Lambers 1966 from Cal-
the genera Microparsus Patch 1908 (several ifornia; and P.falklandicus Hille Ris Lamb-
species), Uroleucon Mcrdvilko 1914 (many ers 1974 and P. tenuis Brown 1987 both
species), Pentamyzus Hille Ris Lambers from the Falkland Islands. The last three
1966 (3 species), Blanchardaphis Ortego, species live on Poaceae and the first one
Nieto Nafria, and Mier Durante 1998 (2 was described on Acaena splendens Hook
species) and Nietonafriella Ortego 1998 (1 & Am. (Rosaceae), but this record (Schou-
VOLUME 104. NUMBER 4 919
teden 1904) was considered doubtful by Results
Hille Ris Lambers (1974) and Brown
( 1987), due to ( 1 ) the known biology of the ideTnhtrifeieeds:pec(ai)esPo.faPcciaitednnaiyez.u(.sSchhaovuetebdeeenn
other species ofthe genus, and (2) the pres-
ence of grass fragments in the specimen B1r90o4w)nfr1o98m7,saomnpelevsiv1ipaanrdou2s; f(ebm)alP.e,tefnruoims
tube of the syntypes collected at San Pi'o sample 3; and (c) a new species from sam-
Cape, Ushuaia in 1892. The four species are
ples 3 and 4.
known only by their respective typical se-
ries (Schouteden 1904; Hille Ris Lambers
Peutamyzusfiie^uiniis Nieto Nafria,
1966. 1974: Brown 1987).
Mier Durante, and Ortego, new species
Materials and Methods (Figs. 1, 2B)
Apterous viviparous female (n = 413; 67
Supported by project LE20/99 (granted measured) (Table 1; Figs. lA. 2B).—When
by the Regional Government of Castilla y alive reddish brown to greenish brown, oval
Leon, Spain), four samples of PenTaniyzus
in shape, and dorsally little convex and rig-
were collected in Tiena del Fuego (Argen-
idly sclerotized: tergites of ab.seg. I to IV
tina) by J.M. Nieto Nafria and M.P. Mier or V form a continuous plate, tergites of
Durante:
thoracic segments and ab.seg.VI. VII and
1) On Acaena spletidens (Rosaceae), Us- VII free (sometimes separation metathorax-
huaia: Tiena Mayor, 9.1.2000 [49 apterous ab.seg.I and ab.seg.IV-V and abd.seg.V-VI
viviparous females, 4 apterous males, and not extending to marginal areas). Mounted
nymphs], see P. acaenae; specimens yellowish with distal ^/i-Vs ofan-
2) on Acaena splendens (Rosaceae). Ushua- tenna, u.r.s., and tarsi brown; well-pigment-
ia: Glacial Martial. 14.1.2000 [6 apterous ed specimens with other pigmented areas:
viviparous females, 2 apterous oviparous
parts of antenna, clypeus, third rostral seg-
females and nymphs], see P. acaenae; ment, coxae and parts of femora and tibiae,
3) on Alopecunis magellanicus van brac- intersegmental sclerites and marginal spots
teolatus (Phil.) M. C. Mariano (Poaceae), on prothorax to ab.seg.IV, plus slightly pig-
Rio Grande, 12.1.2000 [288 apterous vivip- mented anal plate and siphunculi. Frontal
arous females, 4 apterous oviparous fe- tubercles conspicuous, lateral ones diver-
males, 26 apterous males, and nymphs]: see gent and with 1-2 setae; medial one slightly
P. tenuis and the new species; and displaced to ventral part ofhead. Dorsal cu-
4) on Hordeum comosiim J. & C. Presl (Po- ticle sclerotized and more or less alveolat-
aceae), Rfo Grande: San Pablo Cape, ed. Dorsal setae scarce, stiff, short and
12.1.2000 [192 apterous viviparous females, blunt, as antennal ones; ventral setae point-
4 apterous oviparous females and nymphs]; ed, not too stiff, and longer than dorsal
see the new species. ones. Rostrum reaching middle coxae; setae
Abbreviations used in the text are as fol- long, pointed and flexible. Legs relatively
lows: ab.seg. = abdominal segment(s); short; with setae similar to dorsal ones, ex-
ant.Ill, ant.IV = antennal segments III, IV; cept: (1 ) tarsal setae pointed, and (2) ventral
ant.Vb, antVpt = base and processus ter- setae on femora and distal setae on tibiae
minalis of the antennal segment V: BL = pointed and longer than those, especially a
body length; BW = body width; c. = Cau- group of 4 to 6 external and distal setae on
da; D = basal diameter of ant.Ill; IAD = tibiae, normally at most 0.5 times tibial
inter-antennal distance; h.tb. = hind tibia; width at this point. Proximal half of h.tb.
h.t.II = second segment of hind tarsus; s. with 0-4(exceptionally to 9) scent plates
= siphunculus; u.r.s. = ultimate rostral seg- placed inside. Abdominal papillae absent.
ment. Siphunculius slightly sigmoid and clavate.
920 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Fig. L Peiuamyzusfueguimis. A, Apteorus viviparous female, habitus, dorsal view to right and ventral
to left. B, Male, antenna. Scale bar = 1 mm. Illustration by M. Enrique Ortega Lorenzo (Leon. Spain).
— —
.
VOLUME NUMBER
104. 4 921
with a cylindrical part at end and a well- samples 3 and 4, deposited in the authors'
developed flange; wrinkled at base, smooth collections and in The Natural History Mu-
on swollen part and striate on cylindrical seum (London). Museum National
distal neck. Subgenital setae relatively long d'Hisloire Naturelle (Paris), and Zoologisk
and pointed. Gonapophyses conspicuous. Museum, K0benhavns Universitet (Copen-
Cauda more or less elongated-triangular hagen).
—
with convex sides, with long, flexible and Etymology. The specific name is from
pointed setae. Metric and other meristic Tierra del Fuego, in masculine to agree with
data in Table 1 — the gender of the genus.
Alatae viviparous female. Not known Biology and distribution. Pcuhimyzus
and probably does not exist. In material col- fuegiiinus is a monoecious species with ap-
lected, several thousand nymphs and none terous males. Their biological cycle is short.
of them alatoid. Males and oviparous females and many
Oviparo—us female (n = 4; 4 measured) male nymphs, which are recognizable by
(Table 1 ). Very similar to viviparous fe- their brown or black appendages, were col-
male. Proximal half of h.tb. lightly swollen lected in early austral summer. Aphids form
and with (exceptionally from 13) 20-44 groups of 4 to 12 specimens on the outface
scent plates, placed inside. Subgenital plate of leaves of Alopecurus mageUcmicus var.
with (8)13-22 and 13-28 discal and pos- bracteolatus and Hordeum comosum,
terior setae, respectively. which grow in moist areas near the Grande
Apterous male (—n = 26; 14 measured) River and a little river on the beach at San
(Table 1; Fig. IB). In life darker than fe- Pablo Cape, respectively (this moist micro-
male, with legs and antenna brown to black habitat is very similar to that reported by
when alive. When mounted, heavily pig- Hille Ris Lambers 1966 for Pentamyzus
mented: ant.Ill to ant.Vpt, u.r.s.. 1^, distal gramiuis). Grasses of dry neighboring en-
part of tibiae and tarsi dark brown, and vironments are not colonized. We looked
head, rostrum, legs, intersegmental and for the species without success on different
stigmatic sclerites, siphunculi, genitalia and grasses in moist and dry environments of
Cauda smoked; several specimens with light the Argentinean TieiTa del Fuego and Pa-
pigmented marginal areas on pre-siphun- tagonia.
cular segments and one transversal bar on
Pentamyzus acaenae (Schouteden 1904)
ab.seg.VIII. Frontomedial tubercle ventral,
larger than faint cephalic lateral ones, and (Fig. 2A)
nodulose as dorsal cuticle ofthorax and ab- Apterous viviparous female (Table 1).
domen. Similar in shape to male ofP. acae- When alive light to green and very convex.
nae, but with more alveolated and darker Dorsum of body heavily sclerotized. nodu-
cuticle, especially on sclerotized areas. lose and unpigmented; tergites of metatho-
Ant.III and ant.IV with 41-77 and 13-30 rax to ab.seg.VI form a continuous plate,
(exceptionally ant.Vb with 4) small, round tergites of ab.seg. VII and VIII mutually
and striated-walle—d secondary sensoria. free. Very few metric differences have been
Type material. Holotype: apterous vi- observed with regard to types [Schouteden
viparous female (measured specimen num- 1904J, the only known specimens; these
ber 2) collected on Alopecurus magellani- differences could be due to different collec-
cus var. bracteolatits at Rio Grande (Tierra tion dates, November and January, but dif-
del Fuego Province. Argentina), 12.1.2000. ferent volume of samples must also be tak-
in collection Universidad de Leon, Depar- en into account. Dorsal setae scarce, stiff,
tamento de Biologia Animal. Paratypes: short and blunt; setae of antenna and legs
other apterous viviparous females, ovipa- similar in shape and in length, except (1)
rous females and males of studied material tarsal setae pointed, and (2) ventral setae of
922 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Table Metric and meristic data of Pentamyzusfueguinus and P. acaenae, apterous vivparous females
1.
(apt. viv. f.). oviparous females (apt. ov. f.) and males (apt. mal.). In square brackets in the apterous vivparous
females column of P. acaenae are data from types.
—
VOLUME 104. NUMBER 4 923
I
[/
n
B
/•/
Fig. 2. Apterous viviparous female. A. PeiUainyziisacaciuie. B, P.fiici^iiiiuts. Head-prothorax (1). prothorax-
mesothorax (2), mesothorax-metathorax (3). metathorax-ab.seg.I (4), ab.seg.IV-ab.seg.V (5). ab.seg.V-ab.seg.VI
(6), ab.seg.VI-ab.seg.VlI (7), ab.seg.VII-ab.seg.VIII (8) intersegmental lines.
femora and di.stal setae oftibiae pointed and tral summer and winged viviparous females
longer than those, especially a group of 4 possibly do not exist (alatoid nymphs have
to 8 external and distal on tibiae, normally not been observed). Aphids live on the
at least 0.5 times tibial width at this point. leaves or shoots of the rosaceous Acaena
Ventral setae pointed and flexible and lon- splendeus, which is very common in the de-
ger than dorsal ones. ciduous forest of the mountainous area of
Apterous oviparous—female (previously the southern half of Tiena del Fuego; this
undescribed) (Table 1). Very similarto vi- plant and other species of Acaena exist in
viparous female. With group of 8—16 scent other areas ofArgentinean Tieira del Fuego
plates on an internal small swollen area at and Patagonia, but the aphid has not been
proximal half of h.tb. Subgenital plate with recorded there.
10-16 discal setae and 16 posterior setae.
Pentamyzus tenuis Brown 1987
Apterous male (previously undescribed)
—
(Table 1). Green, but darker than female, Pentamyzus tenuis is a very peculiar spe-
with smoked head and legs when alive; pig- cies (the body is elongated and the front is
mentation similar to male of P. fueguinus convex). We collected one female, which is
when mounted; dorsal cuticle ofthorax and similar in general to the types (two vivip-
abdomen less nodulose as male of P. fue- arous females and two nymphs), but some
guinus. Ant.Ill, ant.IV and ant.Vb respec- differences have been observed (Table 2).
tively with 61-73, 25-32 and 0-1 second- The host plant in Tierra del Fuego is not
ary sensoria, similar to those new species. the typical host plant, Poa alopecurus
Biology and distribution. Pentamyzus Kunth. (Brown 1987). The presence of this
acaenae is a monoecious species, with ap- aphid in South America, at a locality situ-
terous males. Its life cycle is very short. ated approximately eight degrees to the
Sexuales occur in the first month ofthe aus- west and two degrees to the south of the
924 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Table 2. Metric and meristic data ofapterous viviparous females of Pentaiuyzus tenuis from Falkland
Islands and Tierra del Fuego.
VOLUME 104. NUMBER 4 925
mGP
Z
2b
mRP mGPj-
iGpP)
926 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
to California. The primitive Pentamyzus the last species of a lineage which returned
may have been dioecious, as its ancestor. from South America.
Later, it diversified into two monoecious The three hypotheses are concomitant
subHneages, one rosaceous-feeding and an- with the present theory on the colonization
other grass-feeding. The subHneage on Ro- of South America by the Aphidinae (the
saceae finally established itself on herba- Holarctic origin of this subfamily and its
ceous ones, because there are no other au- subordinated taxa, such as Macrosiphini, is
tochthonous rosaceans species in the far generally accepted, Heie 1996). South
south (this is not suiprising in monoecious America was invaded in different waves by
aphids, for example Chaetosiphon fragae- different lineages of this tribe (so Micro-
folii (Cockerell 1901), Amphorophora gei parsus, Pentamyzus and siphunculi-reticu-
(Borner 1939), or Acyrthosiphon boreale lated aphids, such as Uroleucon, Nietona-
Hille Ris Lambers 1952 [Macrosiphini] liv- friella, and Blanchardaphis, belong to dif-
ing on Rosaceae herbaceous species), and ferent generic groups and live on plants of
P. acaenae belongs to this sublineage. The different families, the first one on Fabaceae
other known Pentamyzus species belong to and last three on Asteraceae).
the other sublinage; in this group the most The three hypotheses may be correct, but
different species are: (i) P. tenuis, which we prefer 1 or, to a lesser extent, 3. because
has a elongated body and is South Ameri- they are the most parsimonious when ex-
can, and (ii) P. graminis, which has several plaining the morphological similarities be-
derivative characteristics such as small-cla- tween P. fueguinus and P. acaenae and the
vate siphunculi, lack of complementary presence of two "special" grass-feeding
u.r.s. setae, and lack of marginal papillae species, P. tenuis (because of its body ap-
(this last characteristic is also present in pearance) and P. graminis (because its de-
other species of the genus) and belongs to rivative characteristics and distribution). In
the returned lineage. either case, only molecular analysis could
(2) The primitive dioecious Pentamyzus allow us to arrive at a conclusion as to
stock was North American, and host di- which of these hypotheses is correct.
verging originated in North America. Later,
Acknowledgments
two sublineages colonized South America
via the Andes. Here we found two possi- We thank Roger Blackman and Paul
bilities: (2a) The northern species on Ro- Brown (The Natural History Museum, Lon-
saceae disappeared. P. acaenae belongs to don) and Ole Heie (Holte, Denmark) for
the rosacean sublineage established in the constructive criticism ofthe manuscript. We
South, P. graminis belongs to the old north- also thank to E. Mendez, E. Martinez and
ern grass sublineage, and P. falklandicus, P. A. Dalmasso, Botanists of the lADIZA
fueguinus, and P. tenuis belong to the (Mendoza, Argentina) for identifying the
southern grasses sublineage; or (2b) all plant species from Tiena del Fuego.
northern species disappeared and P. gra-
minis returned from South America, such as Literature Cited
in hypothesis 1.
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