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Aphis confusaGreen scabious aphidOn this page: Identification & Distribution Other aphids on the same hostIdentification & DistributionAdult apterae of Aphis confusa (see large pale green apterae in pictures below) are pale green, mottled to a greater or lesser degree with darker green. Some small midsummer apterae living low down on the plant are wholly pale yellow, and many are alatiform with secondary rhinaria and wing rudiments. The antennae are 6- or 5-segmented (the latter mainly in small midsummer specimens), with the terminal process 1.5-3.3 times as long as the base of antennal segment VI. The apical rostral segment is 1.1-1.4 times the length of the second hind tarsal segment. The abdominal dorsum is membranous, sometimes with a small siphuncular sclerite. The abdomen has rather small marginal tubercles on tergites I & VII, with occasional ones on other tergites. The posterior hair on the hind trochanter is quite long at 0.6-1.1 times the diameter of the trochanto-femoral suture (cf. Aphis thomasi on Scabiosa, which has the hairs on the hind trochanter shorter, at 0.2-0.5 times the diameter of the trochanto-femoral suture). The siphunculi and cauda are similarly pigmented - dark in green specimens, pale or dusky in yellow ones (cf. Aphis gossypii, where the siphunculi are usually much darker than the cauda). The siphunculi are 0.82-2.21 times the caudal length. The body length of adult Aphis confusa apterae is 1.0-2.3 mm. Note: Aphis confusa is a member of the Aphis frangulae group, and is difficult to distinguish from other members of that group - especially Aphis gossypii, which also occurs on Scabiosa. We are reasonably confident the pictures below do show Aphis confusa rather than Aphis gossypii because of the ant attendance and the similarly dark siphunculi and cauda. Another closely-related species occurring on the same plant species is Aphis thomasi - which is straw yellow, and lives at the stem base and on the roots. The two bright red organisms in the second picture below are parasitic mites.
Image above by permission, copyright El Gritche, all rights reserved. Alatae (not pictured) and alatiform apterae of Aphis confusa have 3-7 sensory rhinaria on antennal segment III, 0-1 on IV and 0 on V. The abdomen is yellow or green, the siphunculi are black and the abdomen has marginal and very large postsiphuncular sclerites, dorsal cross bars on tergites (VI), VII & VIII, and frequently some other small sclerites.
Image above by permission, copyright El Gritche, all rights reserved. Aphis confusa is found on field scabious (widow flower, Knautia arvensis) and sometimes on scabious (Scabiosa) and teasel (Dipsacus). Both colour forms of the aphid (yellow and green) can be found throughout the summer, the green ones mostly in June and July, and the pale yellow ones mostly in July and August. The species is holocyclic with yellowish, reddish or brownish orange oviparae occurring in September/October. Aphis confusa is closely attended by ants, more so in fact than Aphis gossypii. Aphis confusa is found in Europe, including Britain, south to Spain, Italy & Greece, and East to West Siberia. Other aphids on the same hostAphis confusa has been recorded on 1 Dipsacus species (Dipsacus fullonum).
Aphis confusa has been recorded on 4 Knautia species (Knautia arvensis, Knautia dinarica, Knautia dipsacifolia, Knautia integrifolia)
Aphis confusa has been recorded on 9 Scabiosa species (Scabiosa argentea, Scabiosa atropurpurea, Scabiosa austroaltaica, Scabiosa banatica, Scabiosa columbaria, Scabiosa comosa, Scabiosa ochroleuca, Scabiosa sosnowskii, Scabiosa ucranica).
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