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Black bean aphid, BlackflyOn this page: Identification & Distribution Aphis fabae subspecies Other aphids on the same host
Identification & Distribution
In spring Aphis fabae curl the leaves of common spindle (Euonymus europaeus, see first picture below). The adult aptera of Aphis fabae (see second and third picture below) is dark brown to matt black, sometimes with a distinct greenish hue. Their antennae usually have segments III-IV and the base of segment V quite pale, and the terminal process is 1.7-3.5 times the length of the base of antennal segment VI. The Aphis fabae aptera has a variable abdominal sclerotic pattern - which is confined to abdominal tergites 6-8 in smaller apterae, but broken bands are present in larger ones (cf. Aphis gossypii which has no dark sclerotized markings on the dorsum). Marginal tubercles are protuberant but small. The longest femoral and tibial hairs are longer than the least width of the tibia. Their siphunculi and cauda are dark (cf. Aphis gossypii, which has the cauda usually paler than the siphunculi). The siphunculi are 0.70-1.81 times the length of the cauda which bears 11-24 hairs. The body length of Aphis fabae adult apterae is 1.2-2.9 mm.
Note: The term Aphis fabae species group is sometimes used to collectively describe Aphis fabae sensu stricto (=Aphis fabae fabae), its subspecies, and related species.
The black bean aphid immatures (see first picture below), especially the immature alatae, often have discrete white wax spots, as do sometimes the adults. The alate Aphis fabae (see second picture below) is similarly coloured to the aptera but has mostly dark antennae and fragmented sclerotic bands across the dorsum.
The black bean aphid host alternates between spindle (Euonymus europaeus) as the primary host and many herbaceous plant species including crops as secondary hosts. It is particularly important as a pest for its direct feeding damage to broad beans (Vicia faba) and as a virus vector in sugar beet. Colonies are usually attended by ants. Sexual forms occur in autumn. Aphis fabae is found throughout the northern continents, and has been introduced to many tropical and subtropical countries where it may reproduce parthenogenetically all year round.
Biology & Ecology
In Europe Aphis fabae sensu lato comprises a complex of sibling-species or -subspecies which can only be distinguished by their choice of secondary host coupled with transfer experiments.
Although one can tentatively assign Aphis fabae on the plants above to a particular subspecies, they also colonise a huge range of other plants (for example many umbellifers) which are not associated with a particular subspecies. Also some hosts, such as docks (Rumex spp), seem to be acceptable to all Aphis fabae subspecies.
Other aphids on same host: