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

Aphidinae : Macrosiphini : Phorodon humulifoliae
 

 

Phorodon humulifoliae

Oriental hop aphid

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

Identification & Distribution

Adult apterae of Phorodon humifoliae on hops (Humulus lupulus) from China are described by Tseng & Tao (1939) as being pale yellowish green or green, with the head, antennae and cauda dark and the siphunculus yellowish brown, especially on its apical half. The head of Phorodon humulifoliae is well demarcated from the pronotum, and the eyes are large, with distinct ocular tubercles. The antennal tubercles are well-developed, each having on the inner/mesial side a protuding conical process directed towards the midline of the body, nearly as long as antennal segment II, bearing about four stout hairs. The antennae extend beyond the middle part of body with the terminal process about 2.3 times as long as the base of antennal segment VI (note the species from Japan pictured below has the terminal process about 3.3 times the length of the base). The rostrum reaches just beyond third coxae. The thorax and abdomen are corrugated. The abdomen is widest at the middle. The siphunculi are a little longer than the third antennal segment, extending beyond the caudal end; they are imbricated, stout and large, swollen and strongly curved on the inner side, and narrowed at the distal end. The cauda is subconical, spinose, about twice as long as its width, its base bearing three long curved hairs on either side. The anal plate is rounded, with some long, curved hairs along the posterior border.

Note: We are indebted to Daisuke Sasaki (Kamikawa Agricultural Experiment Station, Hokkaido Research Organization) who examined the aphids pictured below and concluded that they were an undescribed species of Phorodon, near to the Chinese species Phorodon humulifoliae. It does appear to key out to Phorodon humulifoliae, but with some discrepancies regarding length of terminal process (see above) and the colour: The aptera of the species from Japan pictured below (Phorodon nr. humulifoliae), is reddish- or yellowish-brown with paler patches and pale antennae and cauda - but note its immature alatae show two different colour forms, brown and yellow green - see below.

Images above by permission, copyright Akihide Koguchi, all rights reserved.

The alate of Phorodon humulifoliae appears to be undescribed. The alate of the pictured Japanese aphids (possibly a male) has dark head, antennae, thorax, femora and siphunculi as well as large dark marginal sclerites. The immature alatae of the Japanese species (see pictures below) appear to have two colour forms (or possibly two different species were present on the same bush).

Images above by permission, copyright Akihide Koguchi, all rights reserved.

Phorodon humulifoliae host alternates from Prunus species, mainly Prunus armeniaca and Prunus salicina, to hops (Humulus lupulus). It is known to occur in China in Chekiang & Szechuan, as well as northwest China. The species pictured on this page, here designated as Phorodon nr. humulifoliae, occurs on hops (Humulus) in Japan.

 

Other aphids on the same host

Primary hosts

Phorodon humulifoliae has been recorded from 2 Prunus species (Prunus armeniaca, Prunus salicina).

Secondary hosts

Phorodon humulifoliae has been recorded from 2 Humulus species (Humulus lupulus, Humulus scandens / Humulus japonicus).

Acknowledgements

We are very grateful to Akihide Koguchi, for permitting us to reproduce his images of live Phorodon nr. humulifoliae.

We have used the species account of Tseng & Tao (1938) together with information from Roger Blackman & Victor Eastop in Aphids on Worlds Plants. We fully acknowledge these authors as the source for the (summarized) taxonomic information we have presented. Any errors in 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

  • Tseng, S. & Tao, C. (1938). New and unrecorded aphids of China. Journal of the West China Border Research Society 10(1), 195-224.