Pterocallis nigrostriata (Black-lined alder aphid) identification, images, ecology, control

All adult viviparae of Pterocallis nigrostriata are alate. Immature alatae (see first picture below) are pale green, and have many long capitate hairs on the dorsum. Adult alatae of Pterocallis nigrostriata (see second picture below) are pale greenish yellow, with a brownish thorax & head, and a black patch in the centre of the femur. Antennal tubercles are absent. The antennae are a little shorter than body, 6-segmented with black apices to the segments, and with the terminal process as long as, or shorter than the base of antennal segment VI. Secondary rhinaria are round, in a row, on antennal segment III only. The forewings are characteristically pigmented with bands of fuscous bordering the veins and lines of darker pigment on and between veins near the wing-tip (cf. Pterocallis alnijaponicae, which does not have black markings between the wing veins). There are long dark-tipped spinal tubercles on abdominal tergites 1-4(-5), and black marginal spots on abdominal tergites 3-4. The siphunculi are truncated, smooth, longer than wide at middle. The cauda is globular and constricted at the base, and the anal plate is distinctly bilobed. Body length of Pterocallis nigrostriata alatae is 1.4-2.0 mm.

Pterocallis nigrostriata (black-lined alder aphid) immature alate on sycamore ? at Nobeyama, Japan on Sep. 1, 2019; Akihide Koguchi.

Pterocallis nigrostriata is monoecious on a few alder species, most commonly on Japanese green alder (Alnus firma), Manchurian alder (Alnus hirsuta var sibirica) and Japanese alder (Alnus japonica). They feed on the undersides of the leaves. The oviparae have conspicuous long dark dorsal hairs like the immatures. Pterocallis nigrostriata is so far known from Japan and Korea.

Other aphids on the same host

Pterocallis nigrostriata has been recorded on 4 species of alder (Alnus firma, Alnus hirsuta =Aphis tinctoria, Alnus hirsuta var sibirica =Aphis sibirica, Alnus japonica).

Blackman & Eastop list 11 species of aphids worldwide that occur on Manchurian alder (Alnus hirsuta) (Show World list), Baker (2015) lists 1 aphid species as recorded in Britain (Show British list).
Blackman & Eastop list 9 species of aphids worldwide that occur on East Asian alder (Alnus japonica) (Show World list), Baker (2015) lists none as recorded in Britain (Show British list).
Blackman & Eastop list 6 species of aphid as feeding on Japanese green alder (Alnus firma) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 1 as occurring in Britain (Show British list).

Acknowledgements

We are especially grateful to Akihide Koguchi for allowing us to reproduce the image of Pterocallis nigrostriata from his blog page.
Provisional identification of the specimens from the photos was carried out by Daisuke (@ enyomorihio) and us. We have used the keys and species accounts of Takahashi (1965), Higuchi (1972) (both as Rectocallis nigrostriata) and Quednau (2003), together with information from Roger Blackman & Victor Eastop in Aphids on Worlds Plants. 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

Higuchi, H. (1972). A taxonomic study of the subfamily Callipterinae in Japan (Homoptera:Aphididae). Insecta Matsumurana 35, 19-126. Full text
Quednau, F.W. (2003). Atlas of the Drepanosiphine Aphids of the World. Memoirs of the American Entomological Institute 72, 51.
Takahashi, R. (1965) Some new and little known Aphididae from Japan (Homoptera). Insecta Matsumurana 28(1), 19-61. Full text

Pterocallis nigrostriata

Black-lined alder aphid

Identification & Distribution

Other aphids on the same host

Acknowledgements

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References