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Aphididae : Eriosomatinae : Eriosomatini : Paracolopha
 

 

Genus Paracolopha

Paracolopha aphids

On this page: Paracolopha morrisoni

Paracolopha [Eriosomatini]

Paracolopha have the head and prothorax rather extended from a broadly rounded abdomen. The antennae are very short, but 6-segmented (but sometimes 5-segmented with imperfect division between original segments III & IV), and are 0.10-0.15 times as long as body. The legs are short. The tarsi are 1-segmented or completely separated to 2 segments, not strongly tapering. The first segment of the fore-tarsi are thickened and project anteriorly. The rostrum is long, 0.3-0.4 times the body length; the ultimate segment is slender, converging with almost straight margins. Wax gland plates are arranged longitudinally in 6 rows, but reduced to 4 rows in abdominal tergites V-VII and to 2 rows in tergite VIII. On the exule alate the siphunculi are present on abdominal tergite V displaced towards the midline, surrounded thinly by hairs. The emigrant alate has no siphunculi. The body hairs are short and thinly distributed. The genital plate is not pigmented, and is posteriorly curved. The anal plate forms 2 indistinct lobes, and the cauda is semicircular with 2 hairs.

The Paracolopha genus at present includes two species, Paracolopha morrisoni and Paracolopha takahashii. Paracolopha morrisoni is now known to host alternate from Japanese zelkova (Zelkova serrata) to the roots of small bamboos (such as Sasa). Paracolopha takahashii is only known from its secondary host, the base of the sedge Carex breviculmis. It may host alternate from zelkova, or it may be anholocyclic on Carex with no gall generation.

 

Paracolopha morrisoni (zelkova gall-bamboo root aphid)

In East Asia the fundatrices of Paracolopha morrisoni induce galls on its primary host Japanese zelkova (Zelkova serrata, see first picture below). The gall is a club-shaped outgrowth from the upper surface of the leaf lamina between veins, with a narrow stem and a rough swollen apex. Paracolopha morrisoni alatae emerge from their galls and emigrate to bamboos where they colonise the roots (see second picture below). The emigrant alate has the head and thorax dark brown, the antennae and legs are brown, and the abdomen is wholly membranous. The antennae (see third picture below) are usually 6-segmented (sometimes 5-), with antennal segment III relatively short: being 0.53-0.86 times the length of IV, V and VI combined. There are secondary rhinaria on segments III-VI. The apical rostral segment is 0.71-0.84 times as long as the second hind tarsal segment, and bears 5-8 hairs. Siphunculi are absent. The body length of adult Paracolopha morrisoni alate is 1.35-2.36 mm.

First image above copyright Anonymous under a Creative Commons Attribution-Share Alike 3.0 Unported Licence.
Second image public domain, courtesy Smithsonian National Museum of Natural History.

Paracolopha morrisoni apterae on roots of bamboo (not pictured) are globular, pale yellow and with greyish legs and antennae. They are completely covered with white filamentous wax. They have very small siphunculi, one-segmented tarsi and long, stout claws. The body length of adult apterae is 1.5-1.8 mm.

The primary host of Paracolopha morrisoni, which bears the galls, is Japanese zelkova (=keyaki , Zelkova serrata). In Japan and south China Paracolopha morrisoni host alternates from keyaki to the roots of various bamboo (Sasa species). In the USA it has been found as anholocyclic populations on the roots of several other genera of bamboos (Arundinaria, Phyllostachys and Pleioblastus, but apparently not Bambusa). Paracolopha morrisoni has been present on bamboo roots in nurseries in England since at least 1998, and has also been recorded in Denmark, Netherlands, Germany, France and the Czech Republic.

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Acknowledgements

We have used the genus and species accounts of Akimoto (1985) together with information from Roger Blackman & Victor Eastop in Aphids on Worlds Plants. We fully acknowledge these authors and those listed in the reference sections 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

  • Akimoto, S. (1985). Taxonomic study of gall aphids, Colopha, Paracolopha and Kaltenbachiella (Aphidoidea: Pemphigidae) in East Asia, with special reference to their origins and distributional patterns. Insecta Matsumumurana 31, 1-79. Full text