��è����Ƶ

Farmers who kill pests with sprays made from the bacterium Bacillus
thuringiensis(Bt) might soon have another bacterial weapon to hand. Paul
Jarrett, Alun Morgan and their colleagues at Horticulture Research International
in Warwickshire have identified a toxin from the soil bacterium Xenorhabdus
nematophilus that could be as effective against pests as the toxin produced
by B. thuringiensis. Already, Jarrett and Morgan have shown that the Xn
toxin kills the larvae of Aedes aegypti, the mosquitoes that carry
yellow fever. It also kills the larvae of many horticultural pests, including
those of the cabbage root fly and the tomato moth.