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Chaitophorus populeti

Poplar shoot aphid

On this page: Identification & Distribution  Biology & Ecology  Damage & Control 

Identification & Distribution:

Adult Chaitophorus populeti apterae are oval, shiny dark green to black. There is sometimes a paler stripe along the midline of the thorax and the front of the abdomen. There are separate bands on the pre- and mesonotum and abdominal tergites 7-8. The antennae are more than half the length of the body. The terminal process is about twice the length of the base of the last antennal segment. The siphunculi are dark. The body length of Chaitophorus populeti is 1.5-2.9 mm.

Chaitophorus populeti alates (see second picture above) are dark green to black with broad brown dorsal abdominal cross-bands and marginal plates. The wing veins are brown-shadowed.

The poplar shoot aphid lives on the young shoots and terminal leaf petioles of various poplar (Populus) species, especially of the aspen (Populus tremula) and white poplar (Populus alba). It is usually attended by ants. Oviparae and males occur in October-November. Chaitophorus populeti is found throughout the Palaearctic region.

 

Biology & Ecology:

Chaitophorus populeti is the commonest stem-feeder in the genus and feeds on several species of poplar and on aspen. There are several different colour forms of the nymphs, the commonest of which are green and reddish-brown.

 

The first image shows two adult apterae with greenish nymphs. The second image above shows a reddish alate with similarly coloured nymphs. The dorsal pattern on the nymphs remains constant irrespective of the background color. The most dramatic colour form we have encountered is the golden-yellow form shown below:

Most of the aphids on just one aspen sucker were yellow patterned with gold. The functional significance of this colour polymorphism is unknown.

The poplar shoot aphid is nearly always attended by (and vigorously defended by) ants, including various species of Formica), Lasius and Myrmica. The two images below show poplar shoot aphid being attended by southern wood ants. The second of these shows a wood ant (Formica rufa) in its full defensive posture, with mandibles open wide and abdomen swung forward ready to spray a mixture of formic acid and gland secretions into any potential attacker.

 

Novgodorova (2005)  carried out an experimental study on attendance of Chaitophorus populeti by several species of ants including red wood ants (Formica) and black ants (Lasius). He placed adult and larval ladybirds (Coccinella septempunctata) in Chaitophorus populeti colonies and showed that only ants with large protected territories (such as wood ants) attacked both adult and larval predators. Other species of ants (such as black ants) either protected aphids only from adult ladybirds, or did not guard them at all. Wood ants only killed myrmecophilous (ant-associated) aphids if they were left unattended or were injured.

 

The first image above shows a colony attended by Lasius ants, whilst the second shows a colony attended by Myrmica rubra. Honeydew sugar composition plays an important role in ant-aphid interactions, with ants responding most intensively to honeydew containing high amounts of the sugar melezitose. Fischer & Shingleton (2001)  have shown that Chaitophorus populeti (and Chaitophorus populialbae ) are able to modify the melezitose content of their honeydew, reducing it when there are no ants available to attend them. This is probably because maintaining a high content is costly for aphids since they have to feed faster and increase the rate of converting simple to complex sugars.

Sometimes very large Chaitophorus populeti colonies develop and the ants may not be able to remove all the accumulated honeydew. In these circumstances other honeydew feeders may aggregate in the area including wasps and various species of Diptera. The picture above shows one such fly feeding off the honeydew in the colony.

Sexual forms are usually produced in October, and can be found rather more easily than with most aphid species. The males are small, dark and apterous (see pictures below), with secondary rhinaria on antennal joints III-V inclusive.

   

The oviparae (see picture above) are somewhat larger than apterous viviparae with a membranous dorsum apart from bands across pronotum and abdominal tergite 8 (rarely also 7). Tergite 8 and the subgenital plate have more hairs than in corresponding apterous viviparae. They can be found sitting alone on small branches late into the year.

 

Damage and control

The poplar shoot aphid does not usually seem to be regarded as an important pest other than in relation to honeydew production on ornamental trees. However, Sadeqi et al. (2007)  mention it as one of the more important pests of poplars in Iran where poplar is grown both for wood and as shade trees in urban ecosystems. Also in Iran Mojib et al. (2002)  investigated the coccinellid predator Oenopia conglobata as a possible contributor to an integrated control package for poplar pests such as Chaitophorus populeti.

Acknowledgements

We have made provisional identifications from high resolution photos of living specimens, along with host plant identity. In the great majority of cases, identifications have been confirmed by microscopic examination of preserved specimens. We have used the keys and species accounts of Blackman & Eastop (1994)  and Blackman & Eastop (2006)  supplemented with Blackman (1974) , Stroyan (1977) , Stroyan (1984) , Blackman & Eastop (1984) , Heie (1980-1995) , Dixon & Thieme (2007)  and Blackman (2010) . We fully acknowledge these authors as the source for the (summarized) taxonomic information we have presented. Any errors in identification or information are ours alone, and we would be very grateful for any corrections. For assistance on the terms used for aphid morphology we suggest the figure  provided by Blackman & Eastop (2006).

Useful weblinks 

References

  •  Dixon, A.F.G. & Thieme, T. (2007). Aphids on deciduous trees. Naturalist's Handbooks 29. Richmond

  •  Fischer, M.K. & Shingleton, A.W. (2001). Host plant and ants influence the honeydew sugar composition of aphids. Functional Ecology 15, 544-550. Abstract  Full text 

  •  Mojib, H.G.Z. et al (2002). Effect of temperature on developmental time and oviposition rate of Oenopia conglobata L. (Col.: Coccinellidae) fed on Chaitophorus populeti. Journal of Entomological Society of Iran 22 (1), 1-11. Abstract 

  •  Novgodorova, T.A. (2005). Ant-aphid interactions in multispecies ant communities: Some ecological and ethological aspects. European Journal of Entomology 102, 495-501. Full text 

  •  Sadeqi, E. et al. (2007) The integrated pests control management of native and exotic poplar species and clones in Chaharmahal & Bakhtiary province. Research Institute of Forest and Rangeland, Karaj (Iran). Abstract 

  •  Stroyan, H.L.G. (1977). Homoptera: Aphidoidea (Part) - Chaitophoridae and Callaphidae. Handbooks for the identification of British insects. 2 (4a) Royal Entomological Society of London. Full text 

 

Identification requests

Keith Balmer 9/9/2014

I have some [photos of aphids] on white poplar shoots at Priory Country Park, Bedford (TL080503) on 06/09/14. I'm wondering if they are Chaitophorus populeti please? (I can send samples of these if required).

Images copyright Keith Balmer, all rights reserved.

       

Bob, Influentialpoints:

  • Yes, they are indeed Chaitophorus populeti - nice photos. No need to send specimens - they are very distinctive.

    C. populeti is one of the more photogenic aphid species, and just occasionally one finds more extreme colour variations such as the gold ones we show on our web page.