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Periphyllus obscurus

Dark periphyllus aphid

Identification & Distribution  Biology & Ecology  Damage & Control 
 

Identification & Distribution:

The Periphyllus obscurus aptera is rather small and blackish green. The terminal process of the antenna is 3.2-6.9 times the length of the base of the last antennal segment. The siphunculi are dark and only about as long as the basal width. The hind tibiae are more or less pale without a contrasting dark base and distal section. The cauda is rounded with a constriction near its base and is more than half as long as its basal width. The body length is 1.8-2.6 mm.

The dark periphyllus aphid is found in ant-attended colonies on young shoots, leaf petioles and undersides of leaves of Field Maple (Acer campestre). Aestivating nymphs are apparently not produced. The oviparous female has been described. Periphyllus obscurus is found in central and western Europe.

This shows an aptera of Periphyllus obscurus. It is a rather uncommon species in the UK, although not apparently so in parts of Europe. It is best distinguished from Periphyllus testudinaceus  by the pale hind tibiae (more clearly visible on the aptera in the last picture on this page) together with the fact that all stages are present through the summer with no aestivating nymphs.

 

Biology & Ecology:

This picture shows a colony of Periphyllus obscurus in early August. Note that apterae and nymphs of several stages are present together - at this time of year, Periphyllus testudinaceus would normally only be present as aestivating nymphs. The very young nymphs of Periphyllus obscurus are green, whilst older nymphs are brownish.

Periphyllus obscurus is usually (or always) attended by ants as shown in this picture where it was vigorously protected by southern wood ants (Formica rufa). Quinet (1997)  recorded it as being attended by Lasius fuliginosus.

 

Damage and control

The species seems to be rather uncommon in UK so is unlikely to reach pest numbers. In Europe, however, it is clearly more abundant and has been recorded as a pest species on ornamental trees and shrubs by Ripka (1999) in Hungary. The rather small colony in the picture below was being predated by a syrphid larva.

Identifications & Acknowledgements

Whilst we make every effort to ensure that identifications are correct, we cannot absolutely warranty their accuracy. 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 species 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).

Useful weblinks 

References

  •  Dixon, A.F.G. & Thieme, T. (2007). Aphids on deciduous trees. Naturalist's Handbooks 29. Richmond

  •  Quinet, Y. et al. (1997). Food recruitment as a component of the trunk-trail foraging behaviour of Lasius fuliginosus (Hymenoptera: Formicidae). Behavioural Processes 40 (1), 75-83. Abstract 

  •  Ripka, G. (1999). Növénykárosító ízeltlábúak a díszfákon és a díszcserjéken: pajzstetvek, levéltetvek, atkák. (Arthropod pests of ornamental trees and shrubs: scale insects, aphids, mites). Növényvédelem 35 (12), 623-626.  Abstract 

  •  Stroyan, H.L.G. (1977). Homoptera: Aphidoidea (Part) - Chaitophoridae and Callaphidae. Handbooks for the identification of British insects. 2 (4a) Royal Entomological Society of London. Full text