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Salad burnet root aphidOn this page: Identification & Distribution Biology & Ecology
Identification & Distribution:Adult apterae of Aphis sanguisorbae are blackish brown, sometimes with copper and red-brown hues on the posterior tergites. The newly moulted aphids are very shiny, but as they age they develop a slight wax bloom giving them a matt appearance. The wax bloom is most apparent on immature Aphis sanguisorbae. The dorsal cuticle usually has a distinct reticulation. The dorsal abdominal pattern is confined to narrow dark bands across tergites 7-8 and small dark intersegmental muscle sclerites. The siphunculi are dark, more or less cylindrical and with hardly any apical flange. The cauda is short, broadly tongue shaped and often very pale. Hairs on the legs are blunt and mostly short.
The aphids found on Salad burnet (Sanguisorba minor) are generally regarded as Aphis sanguisorbae ssp. poterii. They have shorter hairs and more weakly developed marginal tubercles than the nominate species living on Great burnet (Sanguisorba officinalis).
The salad burnet root aphid lives under ant-constructed shelters of soil or chalk particles at the base of salad burnet (Sanguisorba minor). Apterous males and oviparae are produced in autumn. There are few records of this aphid in England (only in Kent, Bedford and Cambridge - and now, with our record, in East Sussex), and one recent record in Wales. However, it is very easy to overlook this aphid, and it is probably widespread on chalk and limestone soils in Britain wherever its host occurs. Aphis sanguisorbae has been widely, but infrequently, recorded from most of Europe and from Israel.
Biology & Ecology:
Usually the only indication that Aphis sanguisorbae is present is tenting with soil or chalk particles over the leaves of the salad burnet as shown in the picture below.
The area of tenting is limited to the youngest bit of growth at the very base of the plant (see first picture below). Under this tenting can be found densely packed, rather small, colonies of Aphis sanguisorbae (see second picture below with tenting removed).
The aphid colony will be found clustered around the basal part of a young shoot of Sanguisorba.
Aphis sanguisorbae colonies produce large amounts of honeydew, and are attended and tented by Lasius ants. In Britain Baker (2009) found Aphis sanguisorbae feeding on basal and subterranean parts of Sanguisorba minor, growing on calcareous soils in Barry and Lavernock in south Wales. It was also sheltered by Lasius niger.
Under the microscope, Aphis sanguisorbae are characterized by having marked dorsal cuticular reticulation visible in the first picture below.
An additional feature, not noted by Stroyan (1984) in his description of the aphid, is the red-brown hues on posterior segments shown in the second picture above.