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Aphidinae : Aphidini : Aphis gossypii


Identification & Distribution

Wingless females of Aphis gossypii are usually medium-sized and blackish green or dark green mottled with lighter green (see first two pictures below). In hot conditions or when crowded they are smaller, and these dwarf forms are a very pale whitish yellow (see third picture below). The dorsum has no dark sclerotized markings. The longest hairs on the third antennal segment are 0.3-0.5 times the basal diameter of that segment. The terminal process of the last antennal segment is 1.7-3.2 times the length of the base of that segment. The apical segment of the rostrum is 1.1 to 1.5 times as long as segment 2 of the hind tarsus. Marginal tubercles are only consistently present on abdominal tergites 1 and 7. The siphunculi are usually dark, but in the dwarf form they may be pale with dark tips. The siphunculi are 1.3-2.5 times as long as the cauda. The cauda is variable in colour from quite pale to dusky to quite dark but it is usually paler than the siphunculi and bears 4-8 hairs (cf. Aphis solanella and Aphis fabae, which have the cauda always dark like the siphunculi and bearing 7-24 hairs). The body length of adult Aphis gossypii apterae ranges from 0.9-1.8 mm.

Third image above copyright CSIRO under a creative commons 3.0 licence.

Aphis gossypii alates (see fourth picture above) have 6-12 secondary rhinaria distributed on the third antennal segment and usually none on the fourth.

Micrographs of whole mounts in alcohol are shown below.

The clarified slide mounts below are of adult viviparous female Aphis gossypii : wingless, and winged.

Micrograph of clarified mounts of aptera and alate, courtesy Favret, C. & G.L. Miller, AphID. Identification Technology Program, CPHST, PPQ, APHIS, USDA; Fort Collins, CO.

The melon- or cotton-aphid is highly polyphagous and does not usually host alternate, reproducing all year round on its chosen host (see below for exceptions to this). In temperate climates it is most often seen in glasshouses on cucurbits (cucumbers and marrows) and begonias, and in gardens on ornamental Hypericum species. In the tropics Aphis gossypii is a major pest of cotton. It is distributed almost worldwide, and is particularly abundant in the tropics.


Biology & Ecology:

Life cycle

Aphis gossypii does not have a sexual phase in the tropics, nor in most of Europe. Some sexual reproduction may be taking place in southern France, although the primary host is unknown. Host alternation and a sexual phase occur more regularly in parts of east Asia and in North America.

  • Several unrelated plants are utilised as primary hosts, including: the 'Indian bean tree' (Catalpa bignonioides), Korean rose, (Hibiscus syriacus), oriental bittersweet (Celastrus orbiculatus), buckthorns (Rhamnus species) and pomegranate (Punica granatum).

  • However some populations regarded as Aphis gossypii, such as those on Indian madder (Rubia cordifolia) in Japan and those on Hibiscus in Korea, seem to function as distinct species.

  • Moreover monoecious holocyclic populations have been found on cotton & hibiscus in China.

    For more details see Blackman's comments on Aphis gossypii.

In most of its geographical range Aphis gossypii consists of races, or divergent clones, which reproduce parthenogenetically.

Aphis gossypii often moves on to the flowers - the picture above shows them colonizing the flowers of Begonia grandis.


Aphis gossypii is quite variable in colour. The picture below shows a 'normal' coloured Aphis gossypii (mottled green) along with some darker aphids. It is possible that the darker aphids were also Aphis gossypii, since Aphis fabae is not recorded from this Hypericum species.

Alternatively this may be a mixed species colony. Our photos have revealed many examples of mixed species colonies, but these are seldom referred to in the literature and there has been little if any work on the dynamics of such colonies. Hill (1987) points out that many ecological studies have failed because of the inability of the observer/recorder to recognise a mixed species population.

The most extreme colour form is the dwarf yellow form, shown below on a cucumber leaf in a greenhouse in Belgium.

Both images above by permission, copyright Marina Dhondt, all rights reserved.

With this dwarf form the siphunculi are not black. As noted by Watt & Hales (1996), the siphunculi have just the apices the dark brown and the basal part yellow like the body. Production of yellow dwarfs in Aphis gossypii is very different from dwarfing produced through lack of nutrition. Although Aphis gossypii is well-known to show phenotypic plasticity in colour and size to an unusual degree even among aphids, the dwarf form seems to represent a distinct developmentally-programmed morph, in the same way as winged and wingless aphids do. Yellow dwarf Aphis gossypii have been observed in the field in Australia and in glasshouse conditions worldwide.

Ant attendance

Colonies may or may not be ant attended. One colony (see picture above) was found around a leaf petiole at junction of leaf and petiole of Hypericum androsaemum - no ants were attending the colony, but a Myrmica ant was feeding at an extra-floral nectary on the plant as shown in the picture below.

On other occasions ants were definitely attending the aphids, as shown above with a Lasius niger ant.


Other aphids on same host:

Secondary hosts


Damage and control

In temperate climates Aphis gossypii is considered an important pest of greenhouse crops such as cucurbits, and ornamentals such as Begonia and calla lily (Zantedeschia aethiopica). Insecticide treatment may be recommended. Outdoors Aphis gossypii is a pest of Hypericum androsaemum and Hypericum inodorum. Leaves may turn yellow and on ornamentals the large amounts of honeydew and exuvia may look unsightly. Soap solution may be used to reduce numbers. In the tropics it is a major pest of many crops including cotton, cucurbits, coffee, cocoa, peppers and okra. Aphis gossypii is known to transmit at least 50 plant viruses.


We are especially grateful to Marina Dhondt in Belgium for her pictures of the dwarf yellow form of Aphis gossypii on cucumbers.

Whilst we make every effort to ensure that identifications are correct, we cannot absolutely warranty their accuracy. We have mostly made 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


  • Blackman, R. L. & Eastop, V. (2006). Aphids on the World's Herbaceous Plants and Shrubs. Vols 1 & 2. J. Wiley & Sons, Chichester, UK. Full text

  • Hill, D.S. (1987). Agricultural insect pests of temperate regions and their control. CUP, Cambridge.

  • Stroyan, H.L.G. (1984). Aphids - Pterocommatinae and Aphidinae (Aphidini). Handbooks for the identification of British insects. 2(6) Royal Entomological Society of London.

  • Watt, W. & Hales, D.F. (1996). Dwarf phenotype of the Cotton Aphid, Aphis gossypii Glover (Hemiptera: Aphididae). Australian Journal of Entomology 35, 153-159. Full text


Identification requests

Patrick Roper 23/7/2014

I have attached a photo of a colony of what seems to be (following the account on your web site) Aphis chloris.

Image copyright Patrick Roper all rights reserved.

As well as my rather inconclusive photo, I have examined the insects with a high powered lens and they certainly agree with the general colour and configuration of your web site photos.

The ants, Lasius niger, are in constant attendance which would seem to be characteristic of true A. chloris rather than the unnamed lookalike. This and a nearby colony are on a plant of Hypericum androsaemum.

These aphids and ants occur in what I call my window box wildlife reserve where I have also recently recorded Aphis farinosa, again using your web site. The box has now been going for nearly nine years and I manage it mainly by watering in dry weather. It started as bare earth, so all species have found their way there under their own steam. Hopefully I will now be able to add to the aphid list.

There is a blog here:

If you have time I should be interested in your views on the Aphis chloris colony.

Bob, Influentialpoints:

  • Your aphids on Hypericum are in fact Aphis gossypii, and not Aphis chloris.

    The aphids on that page of our website were unfortunately misidentified.

    Aphis chloris lives low down at the base of the plant and (as far as we know) is restricted to Hypericum perforatum. The aphid we pictured - Aphis gossypii - lives high up on the stem and flowers - like the ones you found.

    We will correct the website in the near future. [Now done.]

    Which reminds me, I ought have said why our initial identification was problematical.

    Aphid keys generally assume you are using 'clarified permanent mounted specimens' which very few people have the facilities, staff, and cash to do (in UK at least) - hence most practising entomologists use wet preps in alcohol - and mistakes do happen...

Patrick Roper 5/8/2014

I have attached another picture of the Hypericum aphid. As you will see, the colonies are expanding.

Image copyright Patrick Roper all rights reserved.

Bob, Influentialpoints:

  • Your Aphis gossypii on the Hypericum are certainly doing well! They're a bit blacker than ours but Aphis gossypii does vary greatly in colour.