Biology, images, analysis, design...
|"It has long been an axiom of mine that the little things are infinitely the most important" |
Aphis fabae species-group
Black bean aphid, BlackflyOn this page: Identification & Distribution Aphis fabae subspecies Other aphids on the same host
Identification & Distribution:The Aphis fabae adult aptera is matt black or very dark brown, sometimes with a distinct greenish hue. It has a variable abdominal sclerotic pattern - confined to abdominal tergites 6-8 in smaller apterae, but broken bands are present in larger ones. Marginal tubercles are protuberant but small. The antennae usually have segments III-IV and the base of V quite pale. The longest femoral and tibial hairs are longer than the least width of the tibia. Their siphunculi and cauda are dark. The black bean aphid immatures (see second picture below) often have discrete white wax spots, as do sometimes the adults. The body length of Aphis fabae adult apterae is 1.2-2.9 mm.
The black bean aphid host alternates between spindle (Euonymus europaeus) as the primary host and many herbaceous plant species as secondary hosts. 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. In Europe there is a complex of sibling species or subspecies which can only be distinguished by their choice of secondary host coupled with transfer experiments.
Aphis fabae subspecies
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:
We have restricted our listing of aphids on secondary hosts of Aphis fabae to two of the main secondary hosts of Aphis fabae fabae, broad beans (Vicia faba) and poppy (Papaver ).