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Eulachnus brevipilosus

Light green pine needle aphid

On this page: Identification & Distribution Biology & Ecology Other aphids on the same host Damage & Control

Identification & Distribution:

Apterae of Eulachnus brevipilosus are spindle-shaped and slender. They are light green with numerous faint spots and no wax (cf. Eulachnus agilis which is bright green with numerous very dark spots). The antennae have six segments, and are about 0.4-0.5 times body length (cf. Essigella californica  which has very short 5-segmented antennae). The name 'brevipilosus' indicates the aphid is short-haired. The third antennal segment is less than 0.24 mm. long and bears hairs less than 20 µm long (cf. Eulachnus agilis which has the third antennal segment more than 0.25 mm long and bears hairs 20-130 µm long). Also, the setae on the third antennal segment are no longer than the greatest diameter of that segment. The capitate hairs on the dorsal side of the hind tibia are no longer than the diameter of tibia at its midpoint (see micograph below). The legs are rather pale. The body length of an adult Eulachnus brevipilosus aptera is 1.4-2.2 mm.

The micrographs below show a dorsal view of an aptera and a close-up of the short capitate hairs on the hind tibia.

The light green pine needle aphid may be found feeding on needles on pines, especially on Scots pine (Pinus sylvestris) and stone pine (Pinus mugo). It does not host alternate. According to Blackman & Eastop (1994), sexual morphs have not been found - and Eulachnus brevipilosus overwinter as viviparae. However, Zondag (1983) reports (perhaps wrongly) that sexual forms occur in Europe. Eulachnus brevipilosus occurs throughout Europe and parts of Asia, and has been introduced to North America and New Zealand.

 

Biology & Ecology:

Eulachnus brevipilosus are largely solitary and do not form colonies on the pine needles. Like Eulachnus agilis they are cryptophilic (= concealment-loving).

If they are disturbed, they run away and find a hiding place. From the few individuals we have found, they appear to prefer hiding between a needle pair, rather than at the base of the needle which is the preferred site for Essigella californica. We would however need far more observations before we could conclude that this is a consistent difference in behaviour between the two species.

In New Zealand numbers peak in November and April. Several predators have been reported in New Zealand including the coccinellids Adalia bipunctata and Coccinella undecimpunctata, and the chrysopids Depanacra binocula and Micromus tasmaniae.

 

Other aphids on same host:

Eulachnus brevipilosus has been recorded from 5 Pinus species (Pinus cembra, Pinus mugo, Pinus nigra, Pinus pinaster, Pinus sylvestris).

Blackman & Eastop list about 170 species of aphids as feeding on pines worldwide, and provides formal identification keys for aphids on Pinus.

 

Damage and control

Probing and feeding by this species causes chlorotic (yellowish) spots, and needles may fall prematurely. However, Eulachnus brevipilosus numbers are usually suppressed by the predators and fungal disease.

Identifications & Acknowledgements

Whilst we make every effort to ensure that identifications are correct, we cannot absolutely warranty their accuracy. We have mostly made 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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References