Tag Archives: Tuberolachnus salignus

Not all aphids have the same internal biomes

Headline message for those of you too busy to read the whole thing

Aphids have mutualistic symbiotic bacteria living inside them, one set, the primary endosymbionts, Buchnera aphidicola are obligate, i.e. in normal circumstances, the aphid can’t live without them and vice versa. All aphids have them. The others, the secondary symbionts, of which there are, at the last count, more than seven different species, are facultative, i.e. aphids can survive without them and not all aphids have them or the same combination of them. These can help the aphid in many ways, such as, making them more resistant to parasitic wasps, able to survive heat stress better and helping them use their host plants more efficiently. Hosting the secondary symbionts may, however, impose costs on the aphids.

Now read on, or if you have had enough of the story get back to work  🙂

Like us, aphids have a thriving internal ecology, they are inhabited by a number of bacteria or bacteria like organisms. The existence of these fellow travellers and the fact that they are transmitted transovarially, has been known for over a hundred years (Huxley, 1858; Peklo, 1912)*, although their role within the body of the aphids was not entirely understood for some time, despite Peklo’s conviction that they were symbionts and transferred via the eggs to the next generation. Some years later the Hungarian entomologist László Tóth** hypothesised that aphids because the plant sap that they feed on did not contain enough proteins to meet their demands for growth, must be obtaining the extra nitrogen they needed from their symbionts, although he was unable to prove this empirically (Tóth, 1940). This was very firmly disputed by Tom Mittler some years later, who using the giant willow aphid, Tuberolachnus salignus, showed that aphid honeydew and willow phloem sap contained the same amino acids (Mittler, 1953, 1958ab). It was not only aphidologists who were arguing about the nature and role of insect symbionts, as this extract from a review of the time makes clear,

It is not our purpose here to harangue on terminology; suffice it to say that we will use “symbiote” for the microorganism and “host” for the larger organism (insect) involved in a mutualistic or seemingly mutualistic association.” (Richards & Brooks, 1958).

Interestingly it is in this paper that they mention, using the term “provocactive” the use of antibiotics to create aposymbiotic individuals in attempts to prove that the symbionts were first bacteria, and second, benefiting their insect hosts. The concluded that there was enough evidence to suggest that the endosymbionts were involved in some way in the nutritional and possibly reproductive processes of the insects studied, mainly cockroaches. At the time of the review no similar work had been done on aphids. A few years later though, two American entomologists sprayed aphids with several different antibiotics and found that this caused increased mortality and reduced fecundity when compared with untreated ones (Harries & Mattson, 1963). Presaging its future dominance in aphid symbiont work, one of the aphids was the pea aphid, Acyrthosiphon pisum. Antibiotics were also shown to eliminate and damage the symbionts associated with Aphis fabae followed by impaired development and fecundity in the aphid itself adding yet more evidence that the symbionts were an essential part of the aphid biome (Ehrhardt & Schmutterer, 1966). There was, however, still much debate as to how the symbionts provided proteins to the aphids, and although light and electron microscopy studies confirmed that the symbionts were definitely micro-organisms (Lamb & Hinde, 1967; Hinde, 1971), the answer to that question was to remain unanswered until the 1980s although the development of aphid artificial diets (Dadd & Krieger, 1967) which could be used in conjunction with antibiotic treatments, meant that it was possible to show that the symbionts provided the aphids with essential amino acids (Dadd & Kreiger, 1968; Mittler, 1971ab).*** Although the existence of secondary symbionts in other Homoptera was known (Buchner, 1965), it was not until Rosalind Hinde described them from the rose aphid, Macrosiphum rosae, that their presence in aphids was confirmed (Hinde, 1971).   Of course it was inevitable that they would then be discovered in the pea aphid although their role was unknown (Grifiths & Beck, 1973). Shortly afterwards they were able to show that material produced from the symbionts was passed into the body of the aphid (Griffiths & Beck, 1975) and it was also suggested suggested that it was possible that the primary symbionts were able to synthesise amino acids (Srivastava & Auclair, 1975) and sterols (Houk et al., 1976) for the benefit of their aphid hosts (partners). By the early 1980s it was accepted dogma that aphids were unable to reproduce or survive without their primary symbionts (Houk & Griffiths, 1980; Ishikawa, 1982) and by the late 1980s that dietary sterols were provided by the primary symbionts (Douglas, 1988).


Primary symbiont (P) in process of dividing seen next to secondary symbionts (S) and mitochondrion (m) from Houk & Griffiths (1980).

Despite the huge amount of research and the general acceptance that the endosymbionts were an integral part of the aphid’s biome “The mycetocyte symbionts are transmitted directly from one insect generation to the next through the female. There are no known cases of insects that acquire mycetocyte symbionts from the environment or from insects other than their parents” (Douglas , 1989), their putative identity was not determined until 1991 (Munson et al., 1991), when they were named Buchnera aphidicola, and incidentally placed in a brand new genus. Note however, that like some aphids, B. aphidicola represents a complex of closely related bacteria and not a single species (Moran & Baumann, 1994). Research on the role of the primary symbionts now picked up pace and it was soon confirmed that they were responsible for the synthesis of essential amino acids used by the aphids, such as tryptophan (Sasaki et al., 1991; Douglas & Prosser, 1992) and that it was definitely an obligate relationship on both sides**** (Moran & Baumann, 1994).

Now that the mystery of the obligate primary endosymbionts was ‘solved’, attention turned to the presumably facultative secondary symbionts, first noticed more than twenty years earlier (Hinde, 1971)***** began to be scrutinised in earnest. Nancy Moran and colleagues (Moran et al., 2005) identified three ‘species’ of secondary bacterial symbionts, Serratia symbiotica, Hamiltonella defensa and Regiella insecticola. As these are not found in all individuals of a species they are facultative rather than obligate. The secondary symbionts were soon shown not to have nutritional benefits for the aphids (Douglas et al., 2006). They are instead linked to a whole swathe of aphid life history attributes, ranging from resistance to parasitoids (Oliver et al., 2003; 2005; Schmid et al., 2012), resistance to heat and other abiotic stressors (Montllor et al., 2002; Russell & Moran 2006; Enders & Miller, 2016) and to host plant use (Tsuchida et al., 2004; McLean et al., 2011; Zytynska et al., 2016).

And finally, Mittler (1971b) mentions the reddish colouration developed by aphids reared on some of the antibiotic diets and hypothesises that this may be linked to the symbionts. I have written earlier about aphid colour variants and the possibility that the symbionts may have something to do with it. The grain aphid, Sitobion avenae has a number of colour variants and it was suggested that levels of carotenoids present might have something to do with the colours expressed and that in some way this was controlled by the presence of absence of symbionts (Jenkins et al., 1999). More recently Tsuchida and colleagues in a series of elegant experiments on the ubiquitous pea aphid, have shown that the intensity of green colouration is dependent on the presence of yet another endosymbiont, a Rickettsiella (Tsuchida et al., 2010). The authors hypothesise that being green

Pea aphids colour

Elegant demonstration that in some strains of the pea aphid, green colour is a sign of an infection by Rickettsiella (Tsuchida et al., 2010).

rather than pink or red, may reduce predation by ladybirds as has been suggested before (Losey et al., 1997).

New secondary symbionts continue to be discovered and with each discovery, new hypotheses are raised and tested. It would seem that there is a whole ecology of secondary symbionts within the aphid biome waiting to be explored and written about (Zytynska & Weisser, 2016). What are you waiting for, but do remember to come up for air sometime and relate what you find back to the ecology of the aphids 🙂



Buchner, P. (1965) Endosymbiosis of Animals with Plant Microorganisms. Interscience, New York.

Dadd, R.H. & Krieger, D.L. (1967) Continuous rearing of aphids of the Aphis fabae complex on sterile synthetic diet. Journal of Economic Entomology, 60, 1512-1514.

Dadd, R.H. & Krieger, D.L. (1968) Dietary amino acid requirements of the aphid Myzus persicae. Journal of Insect Physiology, 14, 741-764.

Douglas, A.E. (1988) On the source of sterols in the green peach aphid, Myzus persicae, reared on holidic diets. Journal of Insect Physiology, 34, 403-408.

Douglas, A.E. (1998) Mycetocyte symbiosis in insects. Biological Reviews, 64, 409-434.

Douglas, A.E. & Prosser, W.A. (1992) Sythesis of the essential amiono acid trypthotan in the pea aphid (Acyrthosiphon pisum) symbiosis. Journal of Insect Physiology, 38, 565-568.

Douglas, A.E., Francois, C.M.L.J. & Minto, L.B. (2006) Facultative ‘secondary’ bacterial symbionts and the nutrition of the pea aphid, Acyrthosiphon pisum. Physiological Entomology, 31, 262-269.

Ehrhardt, P. & Schmutterer, H. (1966) Die Wirkung Verschiedener Antibiotica auf Entwicklung und Symbionten Künstlich Ernährter Bohnenblattläuse (Aphis fabae Scop.). Zeitschrift für Morphologie und Ökologie der Tiere, 56, 1-20.

Enders, L.S. & Miller, N.J. (2016)Stress-induced changes in abundance differ among obligate and facultative endosymbionts of the soybean aphid. Ecology & Evolution, 6, 818-829.

Griffiths, G.W. & Beck, S.D. (1973) Intracellular symbiotes of the pea aphid, Acyrthosiphon pisum. Journal of Insect Physiology, 19, 75-84.

Griffiths, G.W. & Beck, S.D. (1975) Ultrastructure of pea aphid mycetocystes: evidence for symbiote secretion. Cell & Tissue Research, 159, 351-367.

Harries, F.H. & Mattson, V.J. (1963) Effects of some antibiotics on three aphid species. Journal of Economic Entomology, 56, 412-414.

Hinde, R. (1971) The control of the mycetome symbiotes of the aphids Brevicoryne brassicae, Myzus persicae, and Macrosiphum rosae. Journal of Insect Physiology, 17, 1791-1800.

Houk, E.J. & Griffiths, G.W. (1980) Intracellular symbiotes of the Homoptera. Annual Review of Entomology, 25, 161-187.

Houk, E.J., Griffiths, G.W. & Beck, S.D. (1976) Lipid metabolism in the symbiotes of the pea aphid, Acyrthosiphon pisum. Comparative Biochemistry & Physiology, 54B, 427-431.

Huxley, T.H. (1858) On the agamic reproduction and morphology of Aphis – Part I. Transactions of the Linnean Society of London, 22, 193-219.

Ishikawa, H. (1978) Intracellular symbionts as a major source of the ribosomal RNAs in the aphid mycetocytes. Biochemical & Biophysical Research Communications, 81, 993-999.

Ishikawa, H. (1982) Isolation of the intracellular symbionts and partial characterizations of their RNA species of the elder aphid, Acyrthosiphon magnoliae. Comparative Biochemistry & Physiology, 72B, 239-247.

Jenkins,  R.L., Loxdale, H.D., Brookes, C.P. & Dixon, A.F.G. (1999)  The major carotenoid pigments of the grain aphid Sitobion avenae (F.) (Hemiptera: Aphididae).  Physiological Entomology, 24, 171-178. http://onlinelibrary.wiley.com/doi/10.1046/j.1365-3032.1999.00128.x/pdf

Lamb, R.J. & Hinde, R. (1967) Structure and development of the mycetome in the cabbage aphid, Brevicoryne brassciae. Journal of invertebrate Pathology, 9, 3-11.

Losey, J. E., Ives, A. R., Harmon, J., Ballantyne, F. &Brown, C. (1997). A polymorphism maintained by opposite patterns of parasitism and predation. Nature, 388, 269-272.

McLean, A.H.C., van Asch, M., Ferrari, J. & Godfray, H.C.J. (2011) Effects of bacterial secondary symbionts on host plant use in pea aphids. Proceedings of the Royal Society B., 278, 760-766.

Mittler, T.E. (1953) Amino-acids in phloem sap and their excretion by aphids. Nature, 172, 207.

Mittler, T.E. (1958a) Studies on the feeding and nutrition of Tuberolachnus salignus (Gmelin) (Homoptera, Aphididae). II. The nitrogen and sugar composition of ingested phloem sap and excreted honeydew. Journal of Experimental Biology, 35, 74-84.

Mittler, T.E. (1958b) Studies on the feeding and nutrition of Tuberolachnus salignus (Gmelin) (Homoptera, Aphididae). III The nitrogen economy. Journal of Experimental Biology, 35, 626-638.

Mittler, T.E. (1971a) Dietary amino acid requirements of the aphid Myzus persicae affected by antibiotic uptake. Journal of Nutrition, 101, 1023-1028.

Mittler, T.E. (1971b) Some effects on the aphid Myzus persicae of ingesting antibiotics incorporated into artificial diets. Journal of Insect Physiology, 17, 1333-1347.

Montllor, C.B., Maxmen, A. & Purcell, A.H. (2002) Facultative bacterial endosymbionts benefit pea pahids Acyrthosiphon pisum under heat stress. Ecological Entomology, 27, 189-195.

Moran, N. & Baumann, P. (1994) Phylogenetics of cytoplasmically inherited microrganisms of arthropods. Trends in Ecology & Evolution, 9, 15-20.

Moran, N.A., Russell, J.A., Koga, R. & Fukatsu, T. (2005) Evolutionary relationships of three new species of Enterobacteriaceae living as symbionts of aphids and other insects. Applied & Environmental Microbiology, 71, 3302-3310.

Munson, M.A., Baumann, P. & Kinsey, M.G. (1991) Buchnera gen. nov. and Buchnera aphidicola sp. Nov., a taxon consisting of the mycetocyte-associated, primary endosymbionts of aphids. International Journal of Systematic Bacteriology, 41, 566-568.

Oliver, K.M., Russell, J.A., Moran, N.A. & Hunter, M.S. (2003) Facultative bacterial symbionts in aphids confer resistance to parasitic wasps. Proceedings of the National Academy of Sciences USA, 100, 1803-1807.

Oliver, K.M., Moran, N.A. & Hunter, M.S. (2005) Variation in resistance to parasitism in aphids is due to symbionts not host genotype. Proceedings of the National Academy of Sciences USA, 102, 12795-12800.

Peklo, J (1912) Über symbiotische Bakterien der Aphiden. Berichte der Deutschen Botanischen Gesellschaft, 30, 416-419.

Richards, A.G. & Brooks, M.A. (1958) Internal symbiosis in insects. Annual Review of Entomology, 3, 37-56.

Russell, J.A. & Moran, N.A. (2006) Costs and benefits of symbiont infection in aphids: variation among symbionts and across temperatures. Proceedings of the Royal Society B, 273, 603-610.

Sasaki, T., Hayashi, H. & Ishikawa, H. (1991) Growth and reproduction of the symbiotic and aposymbiotic pea aphids, Acyrthosiphon pisum mainatained on artificial diets. Journal of Insect Physiology, 37, 749-756.

Schmid, M., Sieber, R., Zimmermann, Y.S. & Vorburger, C. (2012) Development, specificity and sublethal effects of symbiont-conferred resistance to parasitoids in aphids. Functional Ecology, 26, 207-215.

Srivastava P.N. & Auclair, J.L. (1975) Role of single amino acids in phagostimualtion, growth, and survival of Acyrthosiphon pisum. Journal of Insect Physiology, 21, 1865-1871.

Tóth, L. (1940) The protein metabolism of aphids. Annales Musei Nationalis Hungarici 33, 167-171.

Tsuchida, T., Koga, R. & Fukatsu, T. (2004) Host plant specialization governed by facultative symbiont. Science, 303, 1989.

Tsuchida, T., Koga, R., Horikawa, M., Tsunoda, T., Maoka, T., Matsumoto, S., Simon, J. C. &Fukatsu, T. (2010). Symbiotic bacterium modifies aphid body color. Science 330: 1102-1104.

Zytynska, S. E. &Weisser, W. W. (2016). The natural occurrence of secondary bacterial symbionts in aphids. Ecological Entomology, 41, 13-26.

Zytynska, S.E., Meyer, S.T., Sturm, S., Ullmann, W., Mehrparvar, M. & Weisser, W.W. (2016) Secondary bacterial symbiont community in aphids responds to plant diversity. Oecologia, 180, 735-747.



*I should point out that although Huxley clearly described the structure and contents of the mycetocytes he had absolutely no idea what they were and what function, if any, they had. Despite the many authors who supported Peklo’s claim that the contents of the mycetocytes were bacteria he was still having to defend himself against detractors more than 50 years later (Peklo, 1953).

Peklo, J. (1953) Microorganisms or mitochondria? Science, 118, 202-206.


**not to be confused with the László Tóth who vandalised Michelangelo’s Pietà

***interestingly, although the existence of primary symbionts in aphids and their possible role in aphid nutrition was by then firmly established, my vade mecum as a student, Tony Dixon’s Biology of Aphids, makes no mention of them at all, although first published in 1973. The first edition of Aphid Ecology (1985) also by Tony Dixon, only devotes three quarters of a page to them, but by the second edition, published in 1998, they get a whole chapter to themselves.

Buchnera appears to have been ‘lost’ but replaced by a yeast like symbiont (Braendle et al., (2003).

Braendle, C., Miura, T., Bickel, R., Shingleton, A.W., Kambhampari, S. & Stern, D.L. (2003) Developmental origin and evolution of bacteriocytes in the aphid-Buchnera symbiosis. PloS Biology, 1, e21. doi:10.1371/journal.pbio.0000021.


*****although Huxley’s description of the unknown structures that he saw in aphids in 1858, does seem to include secondary symbionts as well as the primary ones.




Filed under Aphidology, Aphids

Not all aphids live on leaves

I haven’t written about aphids for a while, so I thought I would indulge myself and tell you about a few of my favourite aphids.  Most people’s perceptions of aphids (assuming that they know what  aphids are of course) is that they live on leaves.  They will I think, also possibly know that they are usually found on the undersides of leaves, although I may be assuming too much here.  In fact, many species of aphid do not live on leaves; a number of species feed on shoots, twigs and branches and some actually feed on the main trunks of trees.  Yet other species live on the roots of trees and herbaceous plants, such as the apple-grass aphid, Rhopalosiphum insertum which can be a pest of apples and cereals, feeding on the leaves and buds of apples and the roots of grasses and cereals.   Another root-feeding aphid that is a double pest, is Pachypappa tremulae, the spruce root aphid, which host alternates between the aerial parts of aspen trees and the roots of Norway spruce; easily visible when infesting the roots of young potted plants due to the presence of white waxy tufts on its rear end.

Some aphids not only live underground feeding on roots, but are entirely dependent on being farmed by ants e.g.  Tetraneura ulmi, which host-alternates between elm and grass roots, and  Forda formicaria, which host-alternates between Pistachio trees and grass roots.



Both these aphids are looked after or ‘farmed’ by the yellow meadow ant Lasius flavus in exchange for donations of honeydew.


These two aphid species, along with a number of others, have an enlarged anal plate surrounded by special hairs that form the so-called trophobiotic organ.  This acts as a storage device that allows the aphid to accumulate honeydew ready for the ants to remove.  Those aphids that have a more casual (facultative) relationship with ants, do not have this organ which is the basis of this remarkable mutualism.

Another aphid that is farmed by ants, but in a somewhat different way, is the rather larger rose root aphid, Maculolachnus submacaula, which as its name suggests, feeds on rose roots.  In this case, the ants allow the aphids above ground but only in an ant tunnel, similar to those produced by termites when they are infesting a building.  I have only ever been lucky enough to see this aphid once, some 35 years ago in Norwich when I was doing my PhD and noticed things that looked like termite trails running up the main stem of one of my rose bushes.  On breaking them open, well I am a curious entomologist, I found to my surprise not only ants but large brown aphids.

Maculolachnus submacula nest


for a better view of the aphid see http://www.afripics.co.za/home/products/product.php?ProductID=1301564582

But of course the really spectacular ones are those that feed on branches of trees such as the giant willow aphid Tuberolachnus salignus (famous for its sharks fin) and those from the genus Stomaphis which feed through the bark of trees such as oak and


sycamore and are possessed of truly enormous mouthparts such as those of Stomaphis aceris which feeds on sycamore

Stomaphis query aceris

This one, despite its enormous mouthparts, is quite difficult to find as it hides underneath the bark, but luckily it is ant attended so if you see ants scurrying around on the bark of sycamore and disappearing underneath loose flaking bits, it is a good bet that if you gently lever off the loose bark you will find yourself in the presence of this weird-looking creature.

The more I learn about aphids the more I find to marvel at.  Aphids really are remarkable and we know so little about so many of them and their weird and wonderful life styles.

Useful References

Blackman, R.L. & Eastop, V.F. (19 94) Aphids on the World’s TreesAn  Identification and Information Guide.  CABI Publishing. http://www.aphidsonworldsplants.info/index.htm

Evenhuis, H.H. (1968)  The natural control of the apple grass aphid,  Rhopalosiphum insertum, with remarks on the control of apple aphids in general in The Netherlands. Netherlands Journal of Plant Pathology, 74, 106-117  http://link.springer.com/article/10.1007/BF02309501#page-1

Farrell, J.A. & Stufkens, M.W. (1989) Flight activity and cereal host relationships of Rhopalosiphum spp. (Homoptera: Aphididae) in Canterbury New Zealand Journal of Journal of Crop and Horticultural Science, 17, 1-7  http://www.tandfonline.com/doi/abs/10.1080/01140671.1989.10428003

Ivens, A.B.F., Kronauer, D.J.C., Pen, I., Weissing, F.J. & Boomsma, J.J. (2012)  Ants farm subterranean aphids mostly in single clone groups – an example of prudent husbandry for carbohydrates and proteins?  BMC Evolutionary Biology, 12:106 http://link.springer.com/article/10.1186%2F1471-2148-12-106


Filed under Aphidology, Aphids

The Curious Case of the Shark-finned Aphid

The large (giant) willow aphid, Tuberlolachnus salignus, is, in my opinion, one of the world’s greatest unsolved mysteries.  This aphid is sometimes regarded as being the largest aphid in the world.  It can reach a length of 5 mm, can weigh up to 13 mg as an adult and the new-born nymphs weigh about 0.25 mg (Hargreaves & Llewellyn, 1978).  You can get an idea of how big it is from the picture below.

willow aphid on finger


This is pretty big for an aphid, although not quite as big as one of my former PhD students (Tilly Collins) liked to pretend!  The picture below used to appear on her website and was the envy of a number of Texan entomologists.  Tuberolachnus salignus, as you might expect, since it feeds through the bark and not on leaves, has rather a long set of stylets, up to  1.8 mm, more than a third of it’s body length (Mittler, 1957).

tilly on aphid

This picture emphasises the first mystery: what is the function of the dorsal tubercle, which so closely resembles a rose thorn, or to me, a shark’s fin.  Nobody knows.  Is it defensive? Unlikely, since T. salignus being a willow feeder is stuffed full of nasty chemicals and very few predators seem to want, or be able to feed on it.  They feed in large aggregations on the stems of their willow tree hosts and can have serious effects on tree growth (Collins et al., 2001).  As the aphids produce a lot of honeydew, they are often ant-attended  (Collins & Leather, 2002) and these also deter potential predators.  In fact the aphid colonies produce so much honeydew in the summer that they attract huge numbers of vespid wasps that are in search of energy-rich sugar sources at that time of year.  These too are likely to make potential predators and parasitoids think twice about approaching the aphids.


Photograph courtesy Dr Tilly Collins

The wasps also cause a problem for researchers and when Tilly was doing her PhD, she used to have to confine her fieldwork to those times of day when the wasps were not around.   In addition, if you crush one of the aphids you will discover that it stains your fingers bright orange and that this stain will last several days if you don’t try too hard to wash it off.  If you get this aphid ‘blood’ on your clothes they will be permanently marked and Tilly used to say that she ought to be paid an extra clothing allowance.

Tuberolachnus salignus, is as far as we can tell, anholocyclic, no males have been recorded and no matter how hard people have tried to induce the formation of males and sexual females, they have not been successful.  This is however, not the second mystery.  The mystery is that every year, in about February, it does a disappearing act and for about four months its whereabouts remain a mystery (Collins et al., 2001).  So we have an aphid that spends a substantial period of the year feeding on willow trees without leaves and then in the spring when most aphids are hatching from their eggs to take advantage of the spring flush, T. salignus disappears!  Does it go underground?  If so, what plant is it feeding on and why leave the willows when their sap is rising and soluble nitrogen is readily available?

So here is a challenge for all entomological detectives out there.  What is the function of the dorsal tubercle and where does T. salignus go for the spring break?

Truly a remarkable aphid and two mysteries that I would dearly love to know the answers to and yet another reason why I love aphids so much.

Collins, C.M. & Leather, S.R. (2002) Ant-mediated dispersal of the black willow aphid Pterocomma salicis L.; does the ant Lasius niger L. judge aphid-host quality. Ecological Entomology, 27, 238-241. http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2311.2002.00390.x/full

Collins, C. M., Rosado, R. G. & Leather, S. R. (2001). The impact of the aphids Tuberloachnus salignus and Pterocomma salicis on willow trees. Annals of Applied Biology 138, 133-140 http://onlinelibrary.wiley.com/doi/10.1111/j.1744-7348.2001.tb00095.x/abstract.

Hargreaves, C. E. M. & Llewellyn, M. (1978). The ecological energetics of the willow aphid, Tuberolachnus salignus:the influence of aphid Journal of Animal Ecology, 47, 605-613. http://www.jstor.org/discover/10.2307/3804?uid=3738032&uid=2&uid=4&sid=21101920521473

Mittler, T. E. (1957). Studies on the feeding and nutrition of Tuberolachnus salignus (Gmehn) (Homoptera, Aphididae). I. The uptake of phloem sap. Journal of  Experimental Biology, 34, 334-341  http://jeb.biologists.org/content/34/3/334.full.pdf

Other resources




Filed under Aphidology, Aphids, EntoNotes