Abstrusomyzus

Abstrusomyzus phloxae

Abstrusomyzus phloxae

Abstrusomyzus Jensen & Stoetzel

So this is a genus that I named back in my postdoc days at the U.S. National Museum collection in Beltsville, Maryland. Manya Stoetzel was my supervisor and mentor in those days, and gave me more support and kindness through grad school and postdoc than I perhaps deserved. In the days of this Abstrusomyzus work, she gave me latitude to work on this relatively obscure group, probably because I had a lot of material and a strong case for a new genus even before I finished my Ph.D. Plus, A. phloxae appears to be an unusually polyphagous species, a characteristic worth knowing about from an agricultural perspective.

In 2013 I discovered the sexual cycle of a species of Abstrusomyzus on roots and runners of  Achillea millefolium near Boise, Idaho.  I have identified the species as A. leucocrini, but I am starting to question the species boundaries that I wrote about when describing the genus.

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Abstrusomyzus phloxae (Sampson)

Some years ago I published some information on this species.

Jensen, A.S. and M.B. Stoetzel. 1999. An examination of the North American aphid species currently placed in Ovatus van der Goot (Hemiptera: Aphididae) with the description of a new genus. Proceedings of the Entomological Society of Washington 101: 39-56.

I had collected it on, or seen samples from, many different plants including,

The aptera of A. phloxae on Apocynum.

The aptera of A. phloxae on Apocynum.

  • Apocynaceae
    • Apocynum androsaefolium
    • Apocynum sp.
  • Asteraceae
    • Achillea sp.
    • Agoseris sp.
    • Centaurea sp.
  • Brassicaceae
    • Capsella hursa-pastoris
  • Caryophyllaceae
    • Cerastium vulgatum
    • Stellaria crispa
  • Cyperaceae
    • Carex densa
  • Fabaceae
    • Trifolium sp
  • Hydrophyllaceae
    • Phacelia nemoralis
  • Liliaceae
    • “Lilies”
  • Plantaginaceae
    • Plantago major
  • Polygonaceae
    • Polygonum paronychia
  • Ranunculaceae
    • Ranunculus sp.
  • Polemoniaceae
    • Phlox subulata
  • Rubiaceae
    • Galium sp.
  • Violaceae
    • Viola sp.

At the time I considered this to be one species, and it may in fact be only one. However, since that paper in 1999 I have collected for many hours in the western U.S. and the most common host I get this species on is Apocynum. On this host, the aphids live on the underside of the leaves and cause a pale discoloration visible from above. This is rather different from how this species lives on many other plants, i.e. on the basal rosette leaves that are adjacent to the ground.