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Dark green willowherb aphidOn this page: Identification & Distribution Other aphids on the same host
Identification & Distribution
Adult apterae of Aphis mirifica (see picture of colony below) are mottled bluish-green or yellowish-green with black siphunculi. Their antennae are mainly pale, with only segments I, II, and distal portion of the antenna dark; the terminal process is 1.6-2.2 times the base of antennal segment VI (cf. Aphis frangulae, whose terminal process is 1.9-3.0 times the base; & cf. Aphis praeterita, which has a terminal process 3.3-4.7 times its base). The apical rostral segment (R IV+V) is 0.98-1.25 times the length of the second hind tarsal segment, and bears only 2 accessory hairs. The dorsum is membranous with narrow pale cross bars occasionally present on tergites VII and VIII. The abdomen has marginal tubercles on tergites I & VII, and frequently also on some of tergites II-VI (cf. Aphis frangulae, which very rarely has marginal tubercles on tergites II-VI). The siphunculi are imbricate, 0.9-1.4 times as long as the cauda. The siphunculi are less than twice as long as the base of antennal segment VI (cf. Aphis frangulae, which has the siphunculi at least twice as long as the base). The cauda is slightly constricted in the middle and bears 5-11 hairs. The body length of adult Aphis mirifica apterae is 1.2-2.2 mm.
Note: we cannot be certain that the aphids shown below are Aphis mirifica as we have been unable to examine specimens. Given the rather late date of the sample (August) it could be the heteroecious Aphis frangulae. However, the aphids below are strongly ant-attended, which suggests they are Aphis mirifica rather than Aphis frangulae.
Image above copyright Pierre Duhem on CC BY-NC creative commons licence.
Aphis mirifica alatae have 6-9 secondary rhinaria on antennal segment III, 0-1 on segment IV, and none on V. There are marginal and postsiphuncular sclerites on the abdomen, short cross bars on tergites VII and VIII, and a dorsal sclerite on VI. The siphunculi are shorter than 1.5 times the base of antennal segment VI.
Aphis mirifica is found on the flowerheads, stems, stem base and undersides of leaves Epilobium angustifolium. The leaves may be curled. When on the upper parts of the plant, the aphids are usually dark green as in the picture above. When they are on stem or below ground level the aphids may be yellowish. The colonies are nearly always ant-attended, and are often ant-tented when low down on the stem. The species is monoecious holocyclic, with apterous males. Aphis mirifica mainly occur in northern Europe, Russia and Kazakhstan, but are also recorded from Italy.
Other aphids on the same host
Aphis mirifica has only been recorded from Epilobium angustifolium.