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Pemphigus protospirae

Poplar spiral gall aphid

On this page: Identification & Distribution 

Identification & Distribution:

In spring, Pemphigus protospirae form green, or green mottled with red, smooth galls formed by thickening, flattening and spiral twisting of the leaf petiole of Populus nigra (see picture below) on the petioles of the leaves of poplar. Pemphigus protospirae fundatrices have antennae about 0.2 × the length of the body and lack siphunculi.

All the second generation Pemphigus protospirae are winged and leave during late spring to early summer. The winged migrants (see picture below left) are greyish-green and lightly covered with waxy powder. The antennae (see picture below right) are 0.33 - 0.40 times the length of the body. The most proximal rhinarium on third antennal segment is distal to the tooth. The number of secondary rhinaria on the third antennal segment is 10-14, on the fourth 2-5, on the fifth 2-4, and on the base of the sixth 2-8.

The winged migrants move to aquatic umbellifers (Apiaceae) as secondary hosts.

Feedback & comments

  • Willem N. Ellis, June 10, 2014

    I just discovered this pdf  on the web; you may find it interesting.

    But it also points to an error (I think!) in your site, in 'aphids on poplar'. The picture of Pemphigus protospirae actually is spyrothecae, compact as it is. This also better fits the terse description by Blackman & Eastop.

  • Bob Dransfield, InfluentialPoints.com  June 10

    Many thanks for the Osdiadacz paper along with your comments on ID of the spiral poplar gall.

    We initially identified it as Pemphigus spyrothecae based on the characteristics of the gall. However, we then examined an alate under the microscope and, using Blackman & Eastop's key (and Dixon's key), it came out instead to Pemphigus protospirae. Frustrating!

    Unfortunately we only had one alate to check, and repeated examination did not do the aphid much good (we looked at it in alcohol as we do not have facilities to prepare permanent mounts).

    We were hoping for more this year to try again, but unfortunately none yet.

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).

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