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Aphididae : Aphidinae : Macrosiphini : Impatientinum


Genus Impatientinum

Impatiens aphids

On this page: Impatientinum asiaticum

Impatientinum [Macrosiphini]

Impatientinum are medium sized pear-shaped aphids. The dorsal cuticle is usually shiny black and strongly sclerotized. The head is smooth and dark with well developed antennal tubercles. Both the apterae and alatae have secondary rhinaria on antennal segment III or segments III-V. The siphunculi are black and tapering, and the cauda is pale and tongue-shaped.

There are six Impatientinum species in the world, four in the Palaearctic zone. The palaearctic species usually host alternate from greenbriers (Smilax) to balsams (Impatiens), but two invasive species live year round on different balsam species.


Impatientinum asiaticum (Asian balsam aphid) Central Asia, Europe

Adult apterae of Impatientinum asiaticum have an extensive shiny black dorsal shield (see first picture below). The un-sclerotized lateral and ventral parts of the abdomen are green, pink or red. The fused apical segments of the rostrum (RIV+V) are 0.84-1.0 times the length of the of the second hind tarsal segment. The apices of the tibiae are dark or black, and the distal parts of the femora are black (cf. Impatientinum balsamines which has the apices of the tibiae pale, and the distal parts of the femora pale or dusky). The siphunculi are black and are 0.63-0.81 times the length of the third antennal segment (cf. Impatientinum balsamines which has the siphunculi 0.57-0.66 times longer than the length of the third antennal segment).

Both images above copyright Marco de Haas, all rights reserved.

The alate Impatientinum asiaticum (see second picture above) is green or pink with a more fragmented dorsal shield than the aptera.

Impatientinum asiaticum is thought to have originated in central Asia. The north Indian subspecies host alternates from Smilax to Impatiens, but outside of Asia the species has lost its primary host. In Europe it lives all year round on the invasive Himalayan balsam (Impatiens glandulifera) and especially small balsam (Impatiens parviflora). It feeds on the undersides of leaves along the main veins, and on the flower stalks. It is not attended by ants, and produces sexual forms on the secondary host. Impatientinum asiaticum is found in south-east England, most of Europe and parts of Asia.



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.F. (2006). Aphids on the world's herbaceous plants and shrubs. Vols 1 and 2. John Wiley & Sons.