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Aphidinae : Macrosiphini : Uroleucon breviscriptum
 

 

Uroleucon breviscriptum

Nondescript green daisy aphid

On this page: Identification & Distribution Other aphids on the same host

Identification & Distribution

Adult apterae of Uroleucon breviscriptum (see first picture below) have the head and body medium green. The antennae have segments I-II and the base of III green, but the remainder of the segments are brown to dark brown. The apical rostral segment (RIV+V) is brown, and is 0.8-1.0 times the second hind tarsal segment. The proximal two thirds of the femora are green but the distal third, and the tibiae and tarsi, are brown. The siphunculi are mainly dark but with a pale basal section, and are 1.4-2.0 times as long as the cauda (cf. Uroleucon erigeronense, which has siphunculi 2.1-2.8 as long as the cauda; and cf. Uroleucon macgillivrayae, which has siphunculi 0.9-1.4 times the cauda). The cauda of Uroleucon breviscriptum is green, bears 7-12 hairs, and tapers to a slender point.

Note: Jensen, in Aphidtrek, says that in life this species does "look an awful lot like Uroleucon erigeronensis" (= Uroleucon erigeronense). So we obviously wondered about the identification of the specimens shown below, given they were collected from Erigeron which has not previously been identified as a host of Uroleucon breviscriptum. However it is apparent from the photo of the aptera (first picture below), that the siphunculi are much less than twice the caudal length, so Uroleucon erigeronense can be ruled out. We wonder if it is another species, mentioned above, namely Uroleucon macgillivrayae. Uroleucon macgillivrayae does have somewhat shorter siphunculi and occurs in eastern North America (where Claude Pilon found the aphids pictured below), unlike Uroleucon breviscriptum which has previously only been found in western North America. Indeed Blackman, in Aphids on Worlds Plants, suggests that Uroleucon macgillivrayae and Uroleucon breviscriptum are one and the same widely distributed species.

Images above by permission, copyright Claude Pilon, all rights reserved.

The alate (not pictured) has the head, prothorax and abdomen yellowish green and the meso- and metathorax yellowish brown. The siphunculi are dark apart from the base and the cauda is green.

Palmer (1952) recorded Uroleucon breviscriptum (as Macrosiphum breviscriptum) from smooth aster (Symphyotrichum laeve as Aster laevis) and New York aster (Symphyotrichum novi-belgii as Aster novi-belgi), and noted that they did not deform or curl the leaves. Oviparae of this species have been found in October. Uroleucon breviscriptum has previously been described as being found in western North America. If it is synonomized with Uroleucon macgillivrayae, the species will be found throughout North America.

 

Other aphids on the same host

Uroleucon breviscriptum has been recorded from 2 species of Symphyotrichum (Symphyotrichum laeve, Symphyotrichum novi-belgii) and now following these observations also from Erigeron strigosus.

Acknowledgements

We are especially grateful to Claude Pilon for pictures of Uroleucon breviscriptum (for more of her excellent pictures see).

Identification of specimens photographed by Claude Pilon was confirmed by Eric Maw by microscopic examination and DNA analysis of preserved specimens. For taxonomic details we have used the keys and species accounts of Palmer (1952) together with Blackman & Eastop (1994) and Blackman & Eastop (2006). 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).

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References

  • Palmer, M.A. (1952). Aphids of the Rocky Mountain Region: including primarily Colorado and Utah, but also bordering area composed of southern Wyoming, southeastern Idaho and northern New Mexico. Thomas Say Foundation, Denver. Full text