Biology, images, analysis, design...
|"It has long been an axiom of mine that the little things are infinitely the most important" |
Anthemid aphidsOn this page: Genus Macrosiphoniella Macrosiphoniella absinthii Macrosiphoniella artemisiae Macrosiphoniella asteris Macrosiphoniella millefolii Macrosiphoniella oblonga Macrosiphoniella pulvera Macrosiphoniella sejuncta Macrosiphoniella subterranea Macrosiphoniella tanacetaria Macrosiphoniella usquertensis
Macrosiphoniella are green or brown aphids often covered with a thin layer of wax powder over most of the body. Their eyes are red. There is no median tubercle and the antennal tubercles are usually well developed with diverging inner sides. The antennae are normally longer than the body. The abdomen normally has crescent shaped sclerites in front of the siphunculi. Dorsal body hairs on many species are on distinctly visible scleroites. Siphunculi are rather short and thick, cylindrical or tapering, with reticulations on the apical 25-75%; the terminal flange is small or absent. The cauda is long and finger shaped.
There are about 110 species of Macrosiphoniella worldwide, mostly in the northern hemisphere. There is no host alternation and all species feed on daisies (Asteraceae), most on species of the division Anthemideae. Many Macrosiphoniella species feed on just one genus of this group, some on just one species. Sexual forms occur in autumn and eggs hibernate on low parts of plants or on dead leaves. When disturbed the aphids tend to drop off their plant and 'play dead'.
Macrosiphoniella absinthii (Absinthe aphid)
The adult apterae of Macrosiphoniella absinthii (see first picture below) are reddish-brown and partly wax-powdered. The head, antennae, legs, siphunculi and cauda are black, and there is a black spot in the centre of the abdomen which is highlighted by a white surround of powdered wax. The spinal body hairs and some of the pleural body hairs of Macrosiphoniella absinthii are placed on dark scleroites, some of which are fused into larger sclerites of cross bands (see first micrograph below). The hind tibiae are black from the base to apex. The siphunculi are very thick and short, 0.13-0.16 times the body length and 1.0 to 1.1 times the length of the cauda; they are reticulated on their apical 48-60%. The body length of the adult Macrosiphoniella absinthii aptera is 1.7-2.5 mm.
The absinthe aphid does not host alternate. Sexual forms (apterous or alate males) occur in autumn. It feeds on the upper parts of absinthe (Artemisia absinthium) and related species. It is not usually ant attended. Macrosiphoniella absinthii occurs in northern and central Europe eastward to Siberia and Iran. Macrosiphoniella absinthii is also found in north Africa and the Mediterranean area, and has been introduced to the USA, Canada and Argentina.
Macrosiphoniella artemisiae (Mugwort aphid)
Macrosiphoniella artemisiae apterae are of moderate size, greyish-green and wax powdered. The antennae and legs are mostly black, except for the base of antennal segment 3 and the basal part of the front femur which are brown. The siphunculi and cauda are entirely black (cf. Macrosiphoniella oblonga which has the cauda green). The body hairs are not placed on dark scleroites, and the sclerites in front of the siphunculi are very pale and hardly visible. The siphunculi are 0.6-0.9 times the length of the cauda (cf. Macrosiphoniella oblonga which has the siphunculi 1.0-1.4 times longer than the cauda). The body length of apterae is 2.3-3.6 mm.
The mugwort aphid lives on the upper parts of mugwort (Artemisia vulgaris) especially amongst the flowers. Sexual forms occur in the autumn, and the species overwinters as eggs. Macrosiphoniella artemisiae is found in Europe, north Asia, North Africa and North America.
Macrosiphoniella asteris (Bronze sea aster aphid)
Adult apterae of Macrosiphoniella asteris are reddish brown suffused with green with a bronze sheen and sometimes a little wax powdering (see pictures below - although these may be oviparae). Dorsal hairs and their black scleroites are sparse and mainly arranged in longitudinal rows. The apical segment of the rostrum (RIV+V) is rather short, only 0.7-0.8 times the length of the second hind tarsal segment; it is not stiletto shaped as in other Macrosiphoniella, but has slightly convex margins. The antesiphuncular sclerites are rather large. The black siphunculi are 1.0-1.2 times the length of the cauda, which is dusky and paler than the siphunculi. The body length of adult apterae is 2.3-3.1 mm.
The alate vivipara has well developed marginal sclerites, and the spinal scleroites are fused in to cross bands on some tergites. The ovipara is similar to the viviparous female, and the apterous male is small and dark.
Macrosiphoniella asteris lives only on sea aster (Aster tripolium), feeding on the upper parts of the stems and the flowers. The species is found in coastal areas over most of Europe.
Macrosiphoniella millefolii (Yarrow aphid)
Apterae of Macrosiphoniella millefolii are of moderate size, green and wax powdered except for a spinal stripe on the abdomen and presiphuncular spots. The antennae, siphunculi and cauda are black; the legs are mostly black except for the basal part of the front femur which is brown. The antennae are 1.0-1.2 times the body length with the terminal process 3.7-4.3 times the length of the basal part. Dark sclerites are present on the sides and just in front of the siphunculi. There are numerous long body hairs on the dorsum positioned on dark scleroites; some of these may be fused into larger sclerites.The siphunculi are 0.12-0.15 times the length of the body and 0.8-0.9 times the caudal length.
The yarrow aphid does not host alternate and feeds on yarrow (Achillea millefolium). It has a sexual stage in its life cycle. It is common and widespread in Europe and North America.
Macrosiphoniella oblonga (Slender mugwort aphid)
Macrosiphoniella oblonga is a distinctive rather elongated apple-green aphid with a darker green spinal stripe. The body hairs are not placed on dark scleroites. The antennae are mostly pale or dusky but with the apices of segments 3 and 4 darker, and segments 5 and 6 dark. The legs are long, thin and pale. The siphunculi are greenish with brownish tips; they are thinnest over the distal one third but broader towards the apex. The siphunculi are 1.0-1.4 times longer than the length of the cauda (cf. Macrosiphoniella artemisiae which has the siphunculi 0.6-0.9 times longer than the cauda). The cauda is green (cf. Macrosiphoniella artemisiae which has the cauda black). The body length of Macrosiphoniella oblonga is 3.0-5.1 mm.
The alate Macrosiphoniella oblonga is elongate bodied with the siphunculi longer than the cauda.
The slender mugwort aphid can be found scattered on the undersides of the lower leaves of mugwort (Artemisia vulgaris) and cultivated chrysanthemum species. It does not form large colonies. Sexual forms can be found in autumn, and the species overwinters as eggs. The male is apterous and very slender. Macrosiphoniella oblonga occurs in Europe and much of north Asia.
Macrosiphoniella pulvera (Powdered sea wormwood aphid)
Adult apterae of Macrosiphoniella pulvera are greyish-green, or greyish white, and are heavily wax-powdered. The antennae are pale on the base of the third antennal segment, but they darken distally. The base of the sixth antennal segment is 1.1-1.3 times the length of the fused apical rostral segments (RV+V). The longest hair on the third antennal segment is 0.7-1.0 times the basal diameter of that segment. The fused apical rostral segments are 1.1-1.4 times the second hind tarsal segment. The siphunculi are pale basally, but dark or black on about the distal half. The cauda is dusky. The body length of Macrosiphoniella pulvera apterae is 1.9-2.9 mm.
The powdered sea wormwood aphid is largely restricted to sea wormwood (Artemisia maritimum) as its host, although it is occasionally found on other Artemisia species. They appear to mainly feed on the small stems, although some authorities record them as feeding on the leaves. Oviparae and small apterous males are produced in September. Macrosiphoniella pulvera are found on the east and the south coast of England, the west coast of Ireland and much of Europe (excluding Italy, Spain & Portugal) and eastwards into Asia.
Macrosiphoniella sejuncta (Large mottled yarrow aphid)
Adult Macrosiphoniella sejuncta apterae are usually green mottled with brownish red, with no wax powdering (see first picture below). The antennae are rather dark, but with a very short pale section at the base of segment III. The first tarsal segment has only 3 hairs. Macrosiphoniella sejuncta siphunculi are greenish brown to brown with paler bases and the cauda is a pale greenish brown. The siphunculi are very thin, slightly swollen at the base, slightly widened at the apex, have reticulation on the apical 48-69%, and are 1.7 to 2.2 times the length of the cauda (cf. Macrosiphoniella millefolii which has siphunculi which are 0.8-0.9 times the length of the cauda). The body length of the adult aptera is 2.5-3.1 mm.
The alate is much like the apterous viviparous female, but is more slender and has well developed marginal sclerites as well as presiphuncular sclerites (see second picture above). The third antennal segment has 30-40 rhinaria. The ovipara is similar to the apterous vivipara, but the cauda is slightly thicker and blunt, and the basal half of the hind tibia is swollen. The male is wingless and small with a body length of only about 2 mm.
Macrosiphoniella sejuncta feeds on the older leaves close to the ground of yarrow (Achillea millefolium). The best way to find these aphids is to shake the host-plants over a sheet placed on the soil under the leaves. The species does not host alternate, but remains all year on yarrow - overwintering in the egg stage. Sexual forms can be found in September and October. The large mottled yarrow aphid is found across Europe east to Western Siberia.
Macrosiphoniella subterranea (Masked ox-eye aphid)
Adult apterae of Macrosiphoniella subterranea (see first picture below) are reddish brown with a rather thick coating of greyish wax except for clearly defined patches on the mid-dorsum and around the bases of the siphunculi. The third antennal segment is mostly pale, and has 10-22 secondary rhinaria. The legs and antennae of Macrosiphoniella subterranea have contrasting pale and black sections. The siphunculi and cauda are black, and the siphunculi are 0.9 -1.15 times the length of the cauda.
Images copyright Graham Hall, all rights reserved.
The alate Macrosiphoniella subterranea (see second picture above) appears to lack the wax-free patch on the mid-dorsum, but is wax free around the bases of the siphunculi.
Macrosiphoniella subterranea usually feeds on the undersides of the leaves of ox-eye daisy (Leucanthemum vulgare) and shasta daisy (Leucanthemum x superba). Sexual forms develop in October and November, and the aphid overwinters in the egg stage. It is rare in Britain, being previously only found in Cumbria and Hertfordshire, but is widely distributed in continental Europe and is also found in North America.
Macrosiphoniella tanacetaria (Tansy aphid)
Macrosiphoniella tanacetaria apterae (see first picture below) are large wax powdered green or pinkish-brown aphids. The antennae are black including the base of the third segment (cf. Macrosiphoniella artemisiae which has the base of antennal segment 3 brown). The legs, siphunculi and cauda are also black. There are no body hairs on dark scleroites. The antennae are 1.0-1.3 times the body length with the terminal process 2.9-3.5 times the length of the base of the last antennal segment. The siphunculi are 0.1-0.2 times the body length and 0.6-0.9 times the length of the cauda. The body length of apterae is 3.2-4.1 mm. The female alate (see second picture below) is much like the Macrosiphoniella tanacetaria aptera.
The principal host plant of Macrosiphoniella tanacetaria is Tansy (Tanacetum vulgare), but the range of reserve hosts seems greater than in most Macrosiphoniella, including records from other Tanacetum species, species of Achillea, Anthemis, Artemisia, Aster, Bidens, Chamaemelum, Chrysanthemum, Dendranthema and Matricaria, and also Salvia officinalis (common sage). Colonies occur on upper parts of stem and between the flowers. Eggs are laid on the stem and withered leaves. Macrosiphoniella tanacetaria is common and widespread throughout Europe extending into North Africa, parts of Asia and the Americas.
Macrosiphoniella usquertensis (Masked yarrow aphid)Adult apterae of Macrosiphoniella usquertensis are brownish with a thick coating of greyish wax except for clearly defined patches on the mid-dorsum and around the bases of the siphunculi - remarkably similar to the wax pattern of Macrosiphoniella subterranea on ox-eye daisy. The third antennal segment is mostly pale, and has 2-11 secondary rhinaria (cf. Macrosiphoniella subterranea which has 10-22 secondary rhinaria on antennal segment III) . The legs and antennae of Macrosiphoniella usquertensis have contrasting pale and black sections. The siphunculi and cauda are black, and the siphunculi are 0.8 -1.0 times the length of the cauda (cf. Macrosiphoniella subterranea the siphunculi of which are 0.9-1.15 times the length of the cauda).
The alate Macrosiphoniella usquertensis (see second picture above) lacks the large wax-free patch on the mid-dorsum, but is wax free around the bases of the siphunculi. It has 20-35 secondary rhinaria on antennal segment III, and the siphunculi are similar in length to or slightly shorter than the cauda (cf. Macrosiphoniella subterranea the siphunculi of which are usually longer than the cauda). Oviparae are reddish and males are alate.
Macrosiphoniella subterranea feeds on yarrow (Achillea millefolium) and other Achillea species, and occasionally field wormwood (Artemisia campestris). It is mainly found near the tips of the lower leaves, and feeding results in premature senescence of the leaves. Oviparae and alate males develop in autumn. The masked yarrow aphid is found throughout Europe, and has been recorded in Canada.