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Genus Paramyzus

Paramyzus aphids

On this page: Genus Paramyzus Paramyzus heraclei

Genus Paramyzus [Macrosiphini]

Paramyzus are rather small pale shiny aphids resembling, but not necessarily closely related to, Myzus aphids. Paramyzus have well developed steep-sided antennal tubercles and long antennae, with a long terminal process. Their apterae have rather large secondary rhinaria on antennal segment III. Antennal and dorsal body hairs are very short. The apical rostral segment (RIV+V) is much longer than the second hind tarsal segment (HTII). The siphunculi are rather long and straight and slightly swollen with a distinct flange. The cauda is short and tongue shaped and bears 4-6 hairs.

There are three Palaearctic species of Paramyzus, two which feed on umbellifers (Apiaceae) and one of which feeds on cinquefoils and strawberries (Rosaceae). They do not host alternate, but live year-round on their respective hosts. Paramyzus are not attended by ants.

 

Paramyzus heraclei (Pale hogweed aphid)

Colonies of Paramyzus heraclei live on the undersides of the leaves of their host, common hogweed (Heracleum sphondylium), causing yellow spotting and vaulting (=arching) of the leaves (see first picture below). The adult apterae are shiny white or pale yellow, with dark red eyes (see second and third pictures below). The appendages are pale, apart from the tarsi which are dark. The antennae are much longer than the body with the terminal process 5.0 to 6.1 times the length of the base of antennal segment VI. Antennal segment III has 4-15 secondary rhinaria on the basal half (cf. Myzus ascalonicus and Myzus persicae which have no rhinaria on antennal segment III). The apical segment of the rostrum (RIV+V) is 1.4-1.7 times the length of the second hind tarsal segment (HTII). The siphunculi are long, straight, slightly swollen, and 2.0-2.5 times the length of the cauda. The body length of adult Paramyzus heraclei apterae is 1.3-1.9 mm.

The alate Paramyzus heraclei (see clarified mount below) has a dark head, thorax and antennae, and a white to greenish yellow abdomen. There are dark marginal sclerites on the abdomen, together with a dark dorsal patch on abdominal tergites III-V and other dark markings.

The pale hogweed aphid does not host alternate, but remains year round on its host hogweed (Heracleum species). Feeding by the aphid results in small yellow spots and arching of the leaf to produce a shallow cavity within which the aphid lives. Yellow oviparae and alate males are produced in autumn with overwintering eggs laid on the old hogweed plant.

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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 sp 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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References

  • Blackman, R.L. & Eastop, V.F. (2006). Aphids on the world's herbaceous plants and shrubs. Vols 1 and 2. John Wiley & Sons.