InfluentialPoints.com
Biology, images, analysis, design...
Aphids Find them How to ID AphidBlog
"It has long been an axiom of mine that the little things are infinitely the most important" (Sherlock Holmes)

Search this site

Calaphidinae : Pterocallis alnifoliae
 

 

Pterocallis alnifoliae

Speckled-alder aphid

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

Identification & Distribution

All adult viviparae of Pterocallis alnifoliae are alatae (cf. Pterocallis alni, Pterocallis essigi and Pterocallis rhombifoliae, which have both apterous & alate adult viviparae). Their immatures (see first picture below) are pale greenish yellow with pale siphunculi; in the fourth instar nymph the body setae are tinged with brown. The alate adults (see second picture below) have a pale greenish yellow abdomen and darker yellow to orange head and thorax. On antennal segment III the secondary rhinaria are often confined to a pigmented area on the middle of the segment, sometimes with a few more apically (cf. Pterocallis alni, whose secondary rhinaria are confined to the basal third of segment III). The apical rostral segment (RIV+V) is 0.92-1.15 times as long as the second hind tarsal segment (HTII). The abdomen has median dorsal processes on abdominal tergites I & II, but only the one on tergite II is well-developed. The bases of their tibiae are black, as are the apical halves of the short, stump-shaped siphunculi. The anal plate is bilobed. The cauda of the adult has a clearly defined constriction, delimiting the terminal part as a knob. The body length of adult Pterocallis alnifoliae alatae is 1.3-1.7 mm.

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

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

The speckled-alder aphid lives and feeds on the undersides of leaves of speckled alder (Alnus rugosa = Alnus incana rugosa) and green alder (Alnus crispa = Alnus alnobetula crispa) (see picture above). Hottes & Frison (1931) reported Pterocallis alnifoliae (as Myzocallis alnifoliae) to be exceedingly abundant on the undersides of leaves of alder in the Ozarkian region of southern Illinois. Oviparae and alate males occur in September-October. Pterocallis alnifoliae is found in the eastern states of the USA and in Canada.

 

Other aphids on the same host

Pterocallis alnifoliae has been recorded from Alnus 3 species (Alnus crispa, Alnus rugosa, Alnus serrulata).

Acknowledgements

We are especially grateful to Claude Pilon for pictures of Pterocallis alnifoliae (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 Hottes & Frison (1931) and Quednau (2003) 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).

Useful weblinks

References

  • Hottes, F.C. & Frison, T.H. (1931). The Plant Lice, or Aphiidae, of Illinois. Illinois Natural History Survey Bulletin 19(3), 123-447. Full text

  • Quednau, F.W. (2003). Atlas of the Drepanosiphine aphids of the world. Part ii. Memoirs of the American Entomological Institute 72, 1-301.