During spring#x2013;summer 1979#x2013;80,bait plants consisting of peas (Pisum sativumL.), dwarf beans (Phaseolus vulgarisL.), broad beans (Vicia fabaL.), and subterranean clover (Trifolium subterraneum L.) were set out and replaced at weekly intervals in the middle of a lucerne crop, a clover crop, and a pea crop. 13 species of aphid were collected from the bait plants. Six of them were considered to be legume aphids#x2236; in decreasing order of frequency,Myzus persicaeSulz.,Acyrthosiphon kondoiShinji,Aulacorthum solani Kltb.,Aphis craccivoa Koch,AcyrthosiphonpisumHarris, andMacrosiphum euphorbiaeC. Thomas. M. persicae was found most frequently on dwarf bean and pea, and A.kondoion dwarf bean and clover. A.solanioccurred at a similar frequency on all bait plants except clover, where very few were found. A.pisumpreferred broad beans to clover and peas and was least frequent on dwarf beans. As expected, A.craccivorawas most commonly found on broad beans. M.euphorbiaewas found in low numbers on all bait plant species except clover on which none was found.The weekly records also showed that the peak flying time of A. pisum,A.craccivora,and M.euphorbiaewas later than the other three species. High numbers of late instar apterae of A.solanion bait plants showed that the apterae of this species were extremely mobile. Weekly records of aphid populations in the clover and lucerne surrounding the bait plants showed that white clover was the main overwintering host forA.solaniand that lucerne was the overwintering host for A.kondoi.Early spring populations ofA. pisumwere at low levels on both lucerne and white clover.
展开▼
