Two Important Host-plants for Black Aphids of the 'Aphis fabae Complex' in the West of France (Homoptera: Aphididae)
Robert, Yvon; Le Gallic, Jean Francois
In Western France, in the main globe artichoke (Cynara scolymus Linnaeus 1 53) cropping area,'black aphids' can cause significant damage to the plants. In the same area, Euonymus japonicus Linnaeus 1781 hedges have been planted around the fields and in housing-estates; they can also be infested with 'black aphids'. In both cases, these aphids are of the 'Aphis fabae Scopoli 1763 complex'. - Host colonisation tests show that most of them are likely to belong to the subspecies A. fabae circiiacanthoidis Scopoli 1763. Furthermore, the possibility for them to colonise indiscriminately japanese spindle tree bushes and globe artichoke plants is shown. This is liable to have implications for aphid control measures. However, when aphids originating from globe artichoke plants are reared on globe artichoke seedlings in a pot where tick beans (Viciafaba Linnaeus 1753) are also present, at least some of them eventually colonise V.faba, and their progeny accept both plant species, thus showing their relationships to the subspecies fabae s. str. This poses the problem of the reliability of host colonisation tests to identify subspecies of 'black aphids' of the` A. fabae group' and of the means through which these became differentiated.