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Genus Essigella

American pine needle aphids

Species Overview: Essigella Essigella californica 

 

Genus Essigella [Eulachnini]

Identification Small, long-bodied greenish to brown or black aphids that are all native to the Americas. They are the New World equivalent of Eulachnus, but are smaller and have rather short 5-segmented antennae. The claws have modified apices - either bifurcate or double.

This genus comprises about 14 species most of which live on the needles of Pinus. They are cryptic when feeding, but move quickly when disturbed.

 

Essigella californica (Monterey pine needle aphid)

The apterae are spindle-shaped and have very short 5-segmented antennae (distinguishes Essigella from Eulachnus species) The thorax is grey-green and the abdomen pale lime green, with or without rather faint brown dorsal spots. The legs are variably pigmented, often mainly pale but with the tibiae darker.

Abdominal tergites 2-4 each have a transverse row of 6 spinopleural hairs, and with 2 marginal hairs on each side. Abdominal tergite 8 has 6-8 hairs. The second hind tarsal segment is less than 1.9 times as long as the first hind tarsal length. The images below are Essigella californica recently discovered in UK. Their identity has now been confirmed by the UK Food and Environment Agency (Fera) molecular diagnostics team who compared our sample with verified specimens of Essigella californica from a New Zealand population: the COI gene was sequenced for both samples and found identical.

 

The Monterey pine needle aphid is native to North America, from British Columbia south to Mexico. In recent years it has been introduced into Europe (France and Spain) and we now have two confirmed sightings in Britain (in Kew and in Kent). We found it on several Montezuma pines (one of its natural hosts in America) growing in the Bedgebury Pinetum in Kent, UK. It has also been found in Australia, New Zealand and Brazil.

Acknowledgements

We would like to especially thank Sharon Reid (of Fera) with whom we are preparing a joint-authored paper reporting the discovery of this pine-feeding aphid new to Britain.

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).

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