SYSTEMATIC TREATMENT OF APHID GENERA
(in alphabetical order) O
About 10 species occurring
in North America and Asia, feeding
exclusively on Compositae-Artemisiinae.
They are probably most closely
related to Macrosiphoniella, although some features such as the
stiletto-shaped R IV+V may be due to convergent evolution on the same host plants.
Holman & Szelegiewicz (1979) revised the palaearctic species, and the
nearctic species were reviewed by Robinson & Halbert (1989). For colour
photos of some unidentified (or unidentifiable) North American species see aphidtrek.org. Most earlier
accounts placed the species in other genera (Macrosiphum, Macrosiphoniella, Narzykulovia). Obtusicauda
anomella (Knowlton & Allen) Appearance in life is unrecorded; BL of
aptera 1.4-2.0 mm. On Artemisia tridentata
in Utah (original
description), and recently fundatrices identified as this species have been
collected on this host plant in Idaho (A. Jensen, aphidtrek.org). Alatae are unknown. Obtusicauda
artemisiphila (Knowlton
& Allen) Colour of apterae in
life is not recorded; BL 1.7-2.1 mm. Alatae are green to blackish green.
Described from Artemisia tridentata in
Utah, and also found in Idaho, Oregon, Nevada and Montana. Obtusicauda
coweni (Hunter) Plate 28b Apterae are dark olive brown to greenish
black, with a metallic lustre; BL 1.2-2.3 mm. On leaves and shoot tips of Artemisia and Seriphidium spp. in western North America. We follow Robinson & Halbert (1989) who
synonymized several species under the name coweni in recognizing a single, variable species. Siphuncular length is particularly
variable, even within a population, but more reliable features are the long
antennal terminal process and the rounded, pigmented scleroites at the bases
of many dorsal abdominal hairs. O.
zerothermum may also be a synonym. The Asian species O. moldavica seems remarkably similar
and also shows wide morphological variation. Monoecious holocyclic; oviparae
and alate males occur in late October-November (BMNH collection). 2n=12. Obtusicauda
dolychosiphon
(Umarov) Apterae are shining
brownish black, BL 1.8-2.9 mm. Described from Artemisia persica in
Tajikistan, and similar aphids have been found in Kazakhstan on A. pauciflora (described as a
subspecies, O. dolychosiphon ssp. praecellens Smailova), and in
Uzbekistan, Kyrgyzstan, Iran and Pakistan (on various Artemisia spp.). Holman
& Szelegiewicz (1979) tabulated morphometric data and reviewed the host
plant range and distribution. Obtusicauda
filifoliae (Gillette
& Palmer) Apterae are are
cinnamon brown to yellowish brown, tinged laterally with yellow ochre; BL
1.7-2.3. On leaves and shoot tips of Artemisia filifolia and A. tridentata in western USA. Monoecious holocyclic; Robinson &
Halbert (1989) examined type specimens of two Knowlton & Allen species
collected in April-May and considered them both to be fundatrices of filifoliae. Obtusicauda
frigidae (Oestlund) Apterae are shining dark metallic green;
BL 1.8-2.3 mm. On leaves and young growth of Artemisia spp. in western North America, and there are also
records from eastern Canada (New Brunswick, Nova Scotia; Smith &
Parron 1978). Monoecious holocyclic; oviparae and apterous males occur in
late September-November, fundatrices in late May (Palmer 1952). Obtusicauda
iranica Sedighi, Hosseini &
Mehrparvar Apterae are shining
blackish brown; BL 1.9-2.7 mm. On terminal parts of shoots of Artemisia and Seriphidium spp. in Iran (Sedighi et al. 2020a). Monoecious holocyclic; oviparae were collected in
early October. Obtusicauda
moldavica (Bozhko) Apterae are blackish, BL 1.95-3.0 mm. On
terminal parts of Artemisia spp. and Seriphidium
spp., forming dense colonies of rather immobile, “dead-looking” aphids
that produce copious honeydew (Holman & Szelegiewicz 1979). In
Moldova, Hungary, Crimea and Kazakhstan. Aphids from an Artemisia sp. in Tajikistan were described as a new species (O.
crassitubia) by Narzikulov
& Umarov (1969), but this was placed as a subspecies of moldavica
by Holman & Szelgiewicz (1979), who tabulated morphometric data for
this group and reviewed host plants and distribution. The latter authors
assigned a single aptera from Pakistan to ssp. crassituba. O. nilkaensis on Artemisia capillaris in Xinjiang,
China (Zhang et al. 1999, described
as Uroleucon nilkaense) is closely
related and a possible synonym, as is O. longicauda Zhang, described from ‘Gramineae’ in Tibet (Zhang & Zhong
1981). Obtusicauda
mongolica Holman & Szelgiewicz Apterae are shining black, slightly
wax-powdered; BL 1.6-2.2 mm. On Artemisia
frigida in Mongolia, and subsequently recorded from A. rupestris in Kazakhstan (Kadyrbekov 2017a).
One or two species in east Asia
resembling Brachycaudus but with
reniform spiracular apertures, and with a long R IV+V adapted for feeding on
Compositae/Asteraceae-Gnaphalieae. Medda & Chakrabarti (1998) provided a
key couplet distinguishing the alatae. Oedisiphum
compositarum van der
Goot Plate 10b Apterae are brownish green with black
siphunculi; BL 1.4-1.8 mm. Alatae have numerous secondary rhinaria on ANT
III-V and an extensive black dorsal abdominal patch. On flower-stalks and
flowers of a Gnaphalium species in
Java (original description), and subsequently (1951) collected from Gnaphalium (= Helichrysum) luteoalbum and
G. japonicum (BMNH collection, leg.
F.W. Rappard), and also from Anaphalis
spp. in north-west India (Medda & Chakrabarti 1998). Oedisiphum
soureni A.N. Basu (= indicum
A.K. Ghosh) Apterae are pale
brown (probably sometimes darker), BL 1.3-1.7 mm. Feeding on undersides of leaves and
inflorescences of Anaphalis spp.,
without causing noticeable injury, in West Bengal, and also recorded from Gnaphalium (= Helichrysum) luteoalbum in
Uttar Pradesh (India). Medda & Chakrabarti (1998) described the alata.
2n=8.
One North
American species on Alnus, related
to Euceraphis. Oestlundiella
flava (Davidson)
All viviparae are alate, delicate, lemon yellow with plumes of bluish
white wax developing on antennae and legs; BL 2.4-3.4 mm. On undersides of leaves of Alnus spp., tending to aggregate on
certain leaves and feed along either side of the mid-rib. Widely distributed in North America (except
the south-east). Apterous oviparae and
alate males occur in October. 2n=8.
One
species with one-segmented tarsi, forming galls on leaves of Japanese elm. Olegia
ulmifoliae (Aoki)
Aptera (fundatrix?) in gall is yellowish, broadly pear-shaped; BL
1.0-1.7 mm. In small galls (fig. 134A
and Stoetzel 1993) on the mid-ribs of leaves of Ulmus japonica in Japan (Hokkaido, Aoki 1973, as Aphanostigma) and east Siberia
(Pashchenko 1988a). The fundatrix is
remarkably fecund; Shaposhnikov (1979b) counted over 1500 eggs and first
instar larvae around one female in a gall in July. Alatae are unknown, dispersal being by
wind-blown first instars. Monoecious
holocyclic, sexuales mating either in the gall or on the leaf surface
(Stoetzel 1993).
One palaearctic species on Galium with paired spinal
protruberances on abdominal tergites 3-5 and unpaired cauda-like processes on
abdominal tergites 6, 7 and 8. The siphunculi are short, curved and
flangeless as in certain other genera associated with Galium. Ossiannilssonia
oelandica Hille Ris Lambers Plate 14c (Fig.29g) Apterae are greenish to lemon yellow with
mainly pale appendages; BL 1.7-2.0 mm. On Galium
boreale, especially in sunny locations, in Sweden, Finland (Heikinheimo 1997, describing alatae) and
Germany. Monoecious holocyclic, with oviparae and alate males in late
August-Septembr (Ossiannilsson 1959b, Heie 1992).
Three European species similar
to Myzus but the head is not spiculose
and alatae have numerous secondary rhinaria on ANT III-V as in Ovatus. Only anholocyclic populations
are known, feeding mainly on Lamiaceae and Boraginaceae. Blackman (2010)
reviewed the genus. Ovatomyzus
boraginacearum Eastop Plate 18a Apterae are whitish to pale greenish
yellow (see
influentialpoints.com/Gallery; but brownish
yellow to orange in overwintering populations); BL 0.9-1.6 mm. Alatae have a
black dorsal abdominal patch and secondary rhinaria distributed III 19-30, IV
7-17, V 1-7. Living scattered on the
undersides of leaves of its host plants, which are mainly Boraginaceae (Anchusa, Echium, Pulmonaria, Symphytum), and less commonly Salvia
spp. (Lamiaceae); also recorded from Geum
urbanum (Rosaceae) and Knautia
arvensis (Dipsacaceae) (Eastop 1987).
Specimens from Eupatorium
cannabinum (Compositae/Asteraceae) described by Theobald (1926) as Myzus eupatorii also seem to be this
species. In Europe (England,
Germany, Netherlands, Sweden, Czech Republic), Iran and Kazakhstan
(Kadyrbekov 2012a), and now also reported from eastern Canada (Skvarla et al. 2017). Apparently entirely
anholocyclic, with a specialised hibernating apterous morph (Müller 1969a, as calaminthae). 2n=12. Ovatomyzus
chamaedrys (Passerini) (Fig.50e) Apterae are yellowish white to whitish green
(darker at colder temperatures); BL 0.8-1.5 mm. Alatae have a black dorsal
abdominal patch and secondary rhinaria distributed III 31-36, IV 11-15, V
0-4. On undersides of leaves of
certain labiates, especially Clinopodium
vulgare and Teucrium spp., and also recorded from Scabiosa columbaria (Dipsacaceae) and Lithodora diffusa (Boraginaceae); the same plant families as O. boraginacearum, but with different
preferred hosts. There are records from England, Wales, Denmark, France,
Spain, Italy, Germany, Austria, Turkey, and it is also reported from
Kazakhstan (Kadyrbekov 2009a, 2012a). Apparently there is no sexual phase. Ovatomyzus
stachyos Hille Ris Lambers (Fig.50d) Apterae are pale greenish white; BL
1.0-1.5 mm. Alatae have a dark dorsal abdominal patch and secondary rhinaria
distributed III 26-44, IV 10-23, V 0-8. On Stachys spp., living dispersed on undersides of older leaves,
often hidden under hairs. In western Europe (Denmark, Sweden, UK, France,
Netherlands, Portugal). Apparently there is no sexual phase. [Apterae
collected from an unidentified climbing plant in China, with 4-segmented
antennae and capitate hairs on head and eighth abdominal tergite, were
identified as fundatrices of O.
stachyos by Su & Qiao (2012), but the identity of these aphids needs
further confirmation, for example by biological studies.] 2n=12.
About ten palearctic species of
Myzus-like aphids, three of which
host-alternate between Pyroideae and Lamiaceae, while the others live
all-year-round on the former secondary hosts. The alatae usually have more
rhinaria than Myzus, and have no
black central abdominal patch. There
are accounts for Europe (Heinze 1960, Müller
1969b),
Fennoscandia and Denmark (Heie 1994), UK and Ireland (Blackman 2010), Japan
(Miyazaki 1971) and Korea (Lee et al.
2002). The native American species
previously placed in Ovatus have
been transferred to a new genus, Abstrusomyzus (Jensen & Stoetzel,
1999). For
the economically important species see Blackman & Eastop 2000, p.314-5. Ovatus
archangelskajae Kadyrbekov Apterae are whitish, with reddish eyes; BL
1.4-1.6 mm. Alatae are undescribed. On leaves of Mentha asiatica and M.
longifolia in south-east Kazakhstan (Kadyrbekov 2008, 2017a). Ovatus
crataegarius (Walker) Plate 17i Apterae in spring colonies are yellowish
green to mid- or darkish green (see
influentialpoints.com/Gallery); BL
1.4-2.4 mm. They feed on the undersides of young leaves of
Pyroidea (Crataegus, Cydonia or Malus), without causing leaf deformation. Alatae have secondary rhinaria distributed III
11-52, IV 2-24, V 0-9. They migrate to found colonies on the undersides of
leaves of Mentha and some other
Lamiaceae (Melissa, Nepeta). Apterae on secondary hosts
are yellowish green, mid- to pale green or greenish white, BL 1.0-1.9 mm.
Colonies may also persist into the summer months on the primary host, e.g. on
pruned hawthorn hedges. The return migration to Crataegus occurs in September.
Anholocyclic overwintering occurs on secondary hosts where climatic
conditions permit. Presumably European in origin, O. crataegarius is now almost world-wide. However, in
Japan, and possibly also in Korea, similar aphids occur on Cydonia, Malus and Chaenomeles sinensis, but not on Crataegus and
Mentha, so could be a
separate taxon, for which the name malicolens
Hori is available. 2n=12. Ovatus
glechomae Hille Ris Lambers Apterae are rather dark, dirty brown or
brownish green, usually darker laterally; BL 1.4-2.0 mm. Alatae have secondary
rhinaria distributed III 10-14, IV 5-9, V 2-5. Living in small colonies at soil level on
etiolated stems and runners of Glechoma hederacea, usually under
stones. In north-west Europe (Netherlands, England, northern Germany,
Sweden). Monoecious holocyclic, with
oviparae and apterous males in September-October. Ovatus
insitus (Walker) Apterae in spring colonies are green,
greenish-yellow or greenish-white, paler than O. crataegarius, rather shiny (see influentialpoints.com/Gallery);
BL 1.6-2.6 mm. They are found on undersides of young leaves of Crataegus spp. or Mespilus germanica, sometimes on other Pyroidea. Alatae have secondary rhinaria distributed III
25-83, IV 9-57, V 1-24. Migration occurs in June to stem bases or rhizomes of
Lycopus spp., especially L. europaeus.
Apterae on Lycopus are shining
green or greenish white, with later generations in August becoming mottled
brown with dark siphunculi; BL 0.9-1.8 mm. In Europe, south-west and central
Asia, and Siberia. The relationship between the very closely related O. insitus and O. crataegarius was studied by Müller &
Hubert-Dahl (1979) and Müller (1980);
there appears to be little or no gene flow between them although they
sometimes form mixed colonies on the same primary host plant. O.
lycopi (Nevsky) is closely related and possibly a synonym. 2n=12. Ovatus (Ovatoides) inulae (Walker) (Fig.34d,e) Apterae are yellow to lemon yellow or pale
green; BL 1.0-1.6 mm. On undersides of leaves, shoot apices and flowers of Pulicaria dysenterica
and Inula spp., and also recorded
from several other composite genera (Adenostyles,
Galactites, Helichrysum). Widely distributed in Europe (England, Belgium,
France, Germany, Portugal, Italy, Greece, former Yugoslavia, Russia), in
North Africa (Tunisia; Boukhris-Bouhachem et
al.
2007), eastward to Turkey and Central Asia.
Monoecious holocyclic, with alate males (Schouteden 1900). Alate males and
small pale yellow oviparae occur in England in October. Ovatus
malisuctus (Matsumura)
Apterae are dark yellowish brown to brownish green with black
siphunculi and distal halves of femora; BL 1.0-1.7 mm. Immatures are shiny yellow (Moritsu
1983). Curling young leaves of Malus spp. (baccata, domestica,
halliana, sieboldii) and Chaenomeles japonica. In China, Japan, Korea, Taiwan, and also
recorded from Georgia (as Myzus
chaenomelis Dzhibladze). There is
no host alternation. Population
ecology and control have been studied in Japan and Korea (e.g. Takeda 1979,
Kim et al., 1986), including
interactions with predators (Hukusima 1963).
2n=12 (Chen & Zhang 1985b). Ovatus
mentharius (van der
Goot) Apterae are greenish white or pale
green with darker green markings (see
influentialpoints.com/Gallery); BL
1.2-1.8 mm. Alatae have secondary rhinaria distributed III 12-21, IV 7-11, V
0-5. On undersides of leaves of Mentha spp. Monoecious holocyclic with alate males. In
Europe and the Middle East; it has also been identified to occur in the
United States where samples on Mentha
dating back to 1935 had previously been recorded as O. crataegarius, but possibly without establishment except in
glasshouse situations (G.L. Miller et
al. 2007).. Ovatus
minutus (van der Goot) Apterae are bright yellow; BL c.1.3 mm.
In curled top leaves, probably of Coleus
aromaticus (= Plectranthus amboinicus), in Java. [Aphids from Leonurus sibiricus in Meghalaya,
India, provisionally identified as minutus
(A.K. Ghosh & Raychaudhuri 1972), were probably Myzus ornatus.] Ovatus
nipponicus Takahashi Apterae are yellow; BL c.1.7-1.9 mm. On Mentha sp(p). in Japan, and also
collected in Korea on Mentha canadensis
(BMNH collection, leg. W.H. Paik). Apparently this species is at least
partially anholocyclic; viviparae occurred in December and March, and an
ovipara was found in late March (original description). |