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Chaitophorinae : Chaitophorini : Chaitophorus pallipes


Chaitophorus pallipes

Black and yellow willow aphid

On this page: Identification & Distribution Biology & Ecology Other aphids on the same host Damage & Control

Identification & Distribution

Adult apterae of Chaitophorus pallipes are yellow with slight green mottling and broad black pleural stripes (see first picture below). The base of antennal segment VI has 2, or rarely 3, hairs, and the longest hair on antennal segment III is about 3 times as long as the basal diameter of that segment. The fused apical rostral segment (RIV+V) is 0.125 mm long, with 1-3 hairs. Abdominal tergites I-VIII all have pale spinal areas (cf. Chaitophorus nigrae, where abdominal tergites VII & VIII are always evenly dark-pigmented across each tergite). Abdominal segments I-VI are all fused. The femora are usually pale, at least on the fore and middle legs. The siphunculi of Chaitophorus pallipes are unpigmented, with a clear surrounding area (cf. Chaitophorus nigrae, which has dusky siphunculi, without any clear surrounding area on the dorsum). The cauda is not knobbed, but is tongue-shaped with margins slighly diverging towards the base (cf. Chaitophorus viminalis, where the cauda is markedly knobbed). The body length of adult Chaitophorus pallipes apterae is 1.8-2.4 mm. First instar immatures are yellow or yellowish green (cf. Chaitophorus nigrae, whose first instars are usually black or sometimes brown or very dark green). Later instars often have green pleural markings (see second picture below of Chaitophorus pallipes colony with immatures).

Note: More information on this species is given in Richards (1972).

Both images above by permission, copyright Claude Pilon, all rights reserved.

Alatae of Chaitophorus pallipes are greenish-yellow with black dorsal abdominal cross-bands (see two pictures below). There are 9-16 secondary rhinaria on antennal segment III, 0-6 on segment IV, and 0-2 on segment antennal V.

First image above by permission, copyright Claude Pilon, all rights reserved.
Second image above, copyright CBG Photography Group under a Creative Commons Zero (CC0) license.

Chaitophorus pallipes is found on the young growth of American pussy willow (Salix discolor), and other Salix species. Their colonies are usually ant-attended. Chaitophorus pallipes occurs in Canada, and has been recorded from several, mainly western, states in the USA (Idaho, Montana, California, Oregon and North Carolina).


Other aphids on the same host

Chaitophorus pallipes is found on Amercan pussy willow (Salix discolor) and several other (unidentified) Salix species.

Blackman & Eastop list 5 species of aphid as feeding on American pussy willow (Salix discolor) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 2 as occurring in Britain (Show British list).


We are especially grateful to Claude Pilon for pictures of Chaitophorus pallipes (for more of her excellent pictures see)

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


  • Richards, W.R. (1972). The Chaitophorinae of Canada (Homoptera: Aphididae). The Memoirs of the Entomological Society of Canada 104 Supplement S87, 1-109. Abstract