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Currant - daisy aphidsOn this page: Nasonovia compositellae cynosbati pilosellae ribisnigri
Genus Nasonovia [Macrosiphini]
Nasonovia are medium-sized green or reddish, rather shiny aphids with a well-marked dorsal sclerotic pattern of pigmented paired intersegmental muscle plates. Adult viviparae may be winged or wingless. There are distinct antennal and median tubercles and the antennae are rather long. The siphunculi are cylindrical and rather long, with little or no apical reticulation The cauda is elongate and rather blunt finger-shaped.
There are about 30-45 Nasonovia species worldwide, which host alternate between currants (Grossulariaceae) and various daisies (Asteraceae), among which the most important are lettuce (Lactuca), Crepis and various species of Hieracium. They are not attended by ants. One species, Nasonovia ribisnigri, is an important and cosmopolitan pest of lettuce.
Nasonovia aquilegiae (Dark-spot columbine aphid) North America
Adult apterae of Nasonovia aquilegiae (see three pictures below) are pale greenish yellow, sometimes with internal reddish markings, and usually with some black dorsal markings. These markings usually include a large shining black dorsal spot which covers abdominal tergites II-V and marginal areas. There also be sclerites on the thorax and tergites VI and VII which are more or less fused into cross bars (cf. Nasonovia heie in Switzerland, which has a dorsal sclerotic pattern consisting of pairs of pale brown spinal, pleural and marginal spots on each segment). Antennae are pale, but with dark tips on segments III-V and the base and tip of VI. Antenna are about 0.8-1.0 times body length, with the terminal process 3.5-6.5 times the base of segment VI (cf. Longicaudus trirhodus, whose terminal process is 1.0-2.3 times the base). The longest hair on antennal segment III is 0.9-1.6 times the basal diameter. There are 6-33 secondary rhinaria on segment III, irregularly placed along one side of the basal 0.5 or more, and 0-3 on segment IV. The apical rostral segment is slender with almost parallel margins, 1.2-2.2 times the second hind tarsal segment. There are well developed, semiglobular marginal tubercles sometimes present on the prothorax and abdominal segments II-V. The siphunculi are 1.1-2.1 times the cauda, thick at base, and gradually attenuating towards their apices. The cauda is tongue-shaped or oblong triangular, blunt and usually with 5 hairs. The body length of adult Nasonovia aquilegiae apterae is 1.6-3.0 mm.
First & third images above copyright Andrew Jensen, second image copyright Sequoia Janirella Wrens,
The alate vivipara of Nasonovia aquilegiae (see first picture below) has an irregular, dark, central spot on tergites III-V. It has more or less perforated, or alternatively separate sclerites, together with spinal spots or cross bars on tergites VI and VII and marginal and postsiphuncular sclerites. Antennae are mainly dark, with 28-44 secondary rhinaria on segment III, 10-24 on IV, and 0-8 on V. The siphunculi are dark or dusky, but with a paler distal part, and the cauda is pale. The second picture below shows a colony of mainly immature Nasonovia aquilegiae on their host, columbine (Aquilegia).
Nasonovia aquilegiae is monoecious on columbine (Aquilegia spp.). Essig (1917), who first described the species, found that crimson columbine (Aquilegia formosa ssp. truncata) was the preferred food plant on the California University campus, though a few specimens were found throughout the season on a nearby species, golden columbine (Aquilegia chrysantha). The small tender shoots and buds were invariably infested and often the plants were considerably injured by the attacks. In California it passed the entire year on the columbine, going as far down around the crown as possible during the winter. In colder climates further north the species is holocyclic with oviparae and alate males in October-November. Nasonovia aquilegiae is widely distributed in North America being found in the USA and Canada.
Nasonovia compositellae (Black-backed daisy aphid) Europe
The adult aptera of Nasonovia compositellae has a black head, and black cross bars across the pronotum and mesonotum. There is an extensive shining black dorsal abdominal shield covering the metanotum and abdominal tergites 1-VI , and tergites VII and VIII with black cross bars (see pictures below) (cf. Nasonovia ribisnigri and Nasonovia pilosellae which have no black dorsal abdominal shield, but only dark intersegmental sclerites between each abdominal segment). The body is dark green, often (as here) strongly tinged with orange-red. The antennae are 0.8-0.9 times the body length. The siphunculi are thick at the base and 1.3-1.6 times the length of the cauda. The cauda is finger-shaped with 7 hairs. The body length of the Nasonovia compositellae adult aptera is 1.8-2.5 mm.
There are two subspecies of Nasonovia compositellae:
Nasonovia compositellae feeds on hawkweeds (Hieracium species). In spring it feeds on the upper sides of the leaves which fold upwards to enclose the colonies, and later colonizing stems and flowers. Nasonovia compositellae subspecies compositellae produces sexuales in autumn and overwinters as eggs. It is found in the north and west of England and in Wales, Scotland and Ireland. Outside Britain it is only known from Norway and Iceland, so it is a true northern subspecies. Nasonovia compositellae ssp. nigra mainly overwinters as parthenogenetic viviparae. It is found in southern England and Wales, and is widely distributed in Europe.
Nasonovia crenicorna Hairy-cornicled geranium_aphid) Western USA
Adult apterae of Nasonovia crenicorna (see first picture below of fundatrix) are light green with a faint dark spinal stripe. The antennae are dark or greenish brown except segment I and the base of segment III. The siphunculi and cauda are very light greenish-brown, and the siphunculi have dark apices. The antennae are 0.8-0.9 times the body length, with the terminal process 4.3-5.6 times the base of segment VI. There are 4-18 very small secondary rhinaria on the basal 0.67 of segment III, with none on IV or V. The longest hair on antennal segment III is 0.85-1.1 times the basal diameter of that segment. The apical rostral segment is 1.8-2.0 times the second hind tarsal segment, with about 30 accessory hairs. The abdominal tergites bear numerous blunt or slightly capitate hairs. There are rather indistinct marginal tubercles present on the prothorax and tergites II-V, although some may be absent. Tarsal segment I has 2 or 3 hairs. The siphunculi are 1.9-2.2 times the cauda, with a distinct, well developed flange, and below this sometimes some polygonal reticulation. The siphunculi are unusual in bearing 5-11 blunt or capitate hairs on the basal 0.67 (just visible in the picture below). The cauda is tongue-shaped, with 16-20 rather short hairs. Body length of the adult Nasonovia crenicorna aptera is 3.5-5.1 mm.
Images above copyright Andrew Jensen under a creative common licence.
The alate vivipara of Nasonovia crenicorna is coloured like the aptera with a pale green abdomen. The antennae are 0.9-1.2 times the body length and bear 12-23 secondary rhinaria on antennal segment III, and none on segments IV & V. The siphunculi are more or less cylindrical, 1.7-2.0 times the cauda and, like the aptera, bear 6-11 hairs, in this case on their basal 0.33-0.67. The cauda has 16-23 hairs.
Nasonovia crenicorna is monoecious on Richardson's geranium (Geranium richardsonii) and sticky purple geranium (Geranium viscosissimum). It is holocyclic, with oviparae and alate males in July-August. The species produces the sexuales fairly early in the year (July-August) to fit with the life cycle of the plant. It is found in western USA.
Nasonovia cynosbati (Dogberry aphid) North America
Adult apterae of Nasonovia cynosbati are pale green, sometimes suffused with red (see largest aphid in first picture below, and the two largest aphids in background of second picture below). Their antennae have dark tips to segments III to VI. The antennal tubercles are well developed. The dorsal abdomen is pale, rarely with rather pale indistinct sclerites. Dorsal body hairs are pointed or blunt - never capitate (cf.Cryptomyzus spp., which have numerous capitate hairs). The abdominal spiracles are partially covered by cowl-like opercula so they appear crescent shaped (cf. Nasonovia ribisnigri, whose spiracles are open oval pores). The siphunculi are pale with dark or dusky tips and taper from the base to the apex (cf. Hyperomyzus spp., which have swollen siphunculi). The siphunculi are 1.2-2.3 times as long as the cauda, and usually have some imbrication, but only on the distal half (cf. Nasonovia houghtonensis, which has spicules over the whole length of its siphunculi). The cauda is triangular, pale or dusky, and usually has 5 hairs (cf. Nasonovia ribisnigri, which has 7 hairs on its cauda). The body length of adult Nasonovia cynosbati apterae is 1.8-3.0 mm.
Images above by permission, copyright Claude Pilon, all rights reserved.
Alatae (not pictured) are pale green or, especially in more northerly populations, with variably developed dark cross-bands or a mid-dorsal patch. Immature Nasonovia cynosbati vary between green, yellow and red, and have pale siphunculi.
Nasonovia cynosbati is found on wild and cultivated currant (Ribes) species. It has also been reported from some genera of Saxifragaceae (Heucheria, Tellima, Borykinia). The images shown here are of a population on Pennsylvania smartweed (Persicaria pennsylvanica). Dogberry aphid may be partially anholocyclic in California. It is not thought to host alternate, and overwinters as eggs laid on Ribes stems. Oviparae and alate males develop in September-October. Nasonovia cynosbati is widely distributed in North America except in the southern USA.
Nasonovia houghtonensis Gooseberry witch-broom aphid) North America
Adult apterae of Nasonovia houghtonensis (see first picture below of a fundatrix) are green to yellow-green to straw-yellow with no dark dorsal markings (cf. Nasonovia grossa in Rocky Mountain region, which has an extensive dark dorsal patch). It has pale siphunculi (sometimes dark tipped) and a pale cauda. The antennae are mainly pale, but the tips of antennal segment IV-V and most of segment VI are dark. The antennae are 0.7-0.8 times the body length (cf. Nasonovia cynosbati in USA, which has antennae 0.8-1.4 times its body length). The terminal process is 3.8-5.9 times as long as the base of segment VI. Secondary rhinaria on segment III are few and rather small, with 2-10 of various sizes irregularly scattered along the segment, and none on segments IV and V. The longest hair on antennal segment III is 1.2-2.0 times the basal diameter of that segment (cf. Nasonovia ribisnigri in USA & Europe, which has the longest hair on that segment 0.7-1.1 times the basal diameter). The apical rostral segment (RIV+V) is 1.4-2.7 times the second hind tarsal segment (HTII). The siphunculi are 0.9-2.1 times the caudal length (dependent on subspecies), and have spinulose imbrication over the entire length (cf. Nasonovia cynosbati, which has spinulose imbrication only on the distal part). The cauda is tongue-shaped, slightly constricted near the middle, with about 5 hairs. The body length of adult Nasonovia houghtonensis apterae is 1.5-2.0 mm.
Images above copyright Andrew Jensen, under a creative common licence.
The alate Nasonovia houghtonensis (see second picture above) has the head and thorax brown, and the abdomen pale green. Sometimes there are pigmented spinal, marginal, postsiphuncular and antesiphuncular sclerites. The antennae are dusky throughout, and the tibiae, siphunculi and cauda are pale.
Nasonovia houghtonensis is monoecious on various currant species (Ribes), with different subspecies often being separated by their host. The species has gained it's common name of gooseberry witch-broom aphid from the tightly rolled terminal leaves Nasonovia houghtonensis houghtonensis produces on gooseberry (Ribes uva-crispa). All subspecies are thought to be holocyclic, with sexuales occurring in autumn. The species is found over much of North America.
Nasonovia pilosellae (Hawkweed aphid) Europe
Adult apterae of Nasonovia pilosellae (see first picture below) are medium-sized yellowish-green or pinkish to blackish, rather shiny aphids. There are dark intersegmental sclerites between each abdominal segment, as well as either an ill-defined patch, or broad transverse bands of dark dorsal pigmentation on the abdomen. The ratio of the length of the terminal process of the last antennal segment to its base ranges from 5.7-8.0 (cf. Nasonovia ribisnigri, in which the ratio of the length of the terminal process of the last antennal segment to its base is 7.0-11.4). The secondary rhinaria on the third antennal segment spread out along one side of the segment (cf.Nasonovia ribisnigri, where the secondary rhinaria on the third antennal segment tend to be concentrated on the basal part of the segment). The first segment of their hind tarsus has two hairs. Their siphunculi are cylindrical and rather long, with little or no apical reticulation The cauda of Nasonovia pilosellae is elongate and rather blunt finger-shaped. The body length of the Nasonovia pilosellae adult aptera is 1.2-2.5 mm.
The Nasonovia pilosellae alate (see second picture above) has a green or pinkish green abdomen with black marginal sclerites. The dark green spino-pleural markings are variably developed.
The hawkweed aphid lives all year round on a few related species of hawkweed, namely the orange hawkweed (Pilosella aurantiaca), common hawkweed (Hieracium lachenalii) and the mouse-ear hawkweed (Hieracium pilosella).
Nasonovia ribisnigri (Currant-lettuce aphid) Europe, West & Central Asia, North & South America
Nasonovia ribisnigri apterae on the primary host (gooseberry and blackcurrant, see first picture below) are shiny green with no dark markings. On their secondary host (various members of the daisy family) Nasonovia ribisnigri apterae are more variable in colour, ranging from green to yellow or pink, and have dark intersegmental sclerites between each abdominal segment (see second picture below). The length of the terminal process is 7.0-11.4 times the length of the base of the antennal segment VI (cf. Nasonovia pilosellae which has the length of the terminal process 3.4-8.3 times longer than the base). The first segment of the hind tarsus has three hairs. Nasonovia ribisnigri siphunculi are pale with dark tips. They are at least as long or longer than the cauda and taper slightly. The cauda is finger shaped, not constricted and the same colour as the basal part of the siphunculi. The body length of Nasonovia ribisnigri apterae is 1.3-2.7 mm.
Alate Nasonovia ribisnigri (see third picture above) have a conspicuous pattern of black abdominal markings. They have 23-66 secondary rhinaria on the third antennal segment, 2-14 on the fourth segment and none on the fifth segment.
The currant-lettuce aphid host alternates from currants (Ribes spp.), especially gooseberry and blackcurrant, to various Asteraceae, including lettuce, as well as Brassicaceae, Scrophulariaceae and Solanaceae. Nasonovia ribisnigri is found throughout Britain and continental Europe east to Ukraine, and has been introduced to North and South America.
Nasonovia williamsi (Leafcurl cinquefoil aphid) Western North America
Adult apterae of Nasonovia williamsi (see picture below) are shining green to yellowish-green to amber yellow. Their antennae are mainly dusky, apart from segment VI which is dark. The antennae are 1.0-1.2 times the body length, with a terminal process that is 5.4-7.7 times the base of antennal segment VI. Secondary rhinaria are protruding and tuberculate, with 23-56 on antennal segment III, irregularly scattered along the whole the segment, 0-22 on segment IV, and 0-1 on V (cf. Acyrthosiphon vandenboschi on Potentilla in California, USA, which has no rhinaria on the antennal segment III). . The apical rostral segment is slender, with almost parallel margins. It is 1.6-1.9 times the length of the second hind tarsal segment, and has 10-19 accessory hairs. There are rather large, pale, smooth, rounded or pear-shaped marginal tubercles present on the prothorax and abdominal segments II-V. The siphunculi are pale, sometimes with a dark apical part; they are almost cylindrical, thicker towards the base, almost smooth, sometimes with one or a few fine hairs, and 1.0-1.8 times the caudal length (cf. Chaetosiphon hottesi on Potentilla in North America, which has longer siphunculi, more than twice as long as the cauda). The cauda is pale, tongue-shaped, rather short and blunt, sometimes constricted, with 5(-6) hairs. The body length of adult Nasonovia williamsi apterae is 1.5-2.3 mm.
Image above copyright Andrew Jensen, under a creative common licence.
The alate vivipara of Nasonovia williamsi may be pale, or it may have dusky or dark, indistinctly limited marginal sclerites and intersegmental pleural sclerites. Secondary rhinaria are tuberculate, with 46-70 on antennal segment III, 23-39 on IV and 3-11 on V. Siphunculi are dusky, pale, or pale with dusky apices.
Nasonovia williamsi is monoecious on two species of cinquefoil (Potentilla) in western North America. These aphids occur on the under side of the leaves, causing them to curl up. Palmer (1952) reports finding apterous summer viviparae from May to August, and alate viviparae from July to August, but they were not common. Sexuales were unknown until Jensen (see Aphidtrek) found oviparae, alate males and eggs on curled basal leaves in Idaho in alate summer and early fall. Nasonovia williamsi is found in western USA (California, Idaho, Utah, Oregon, Nebraska) and Canada (Nebraska, Manitoba).