Levels of resistance to six selected insecticides of
eleven field populations of the filbert aphid Mvzocallis
coryli (Goetze) were determined by using the leaf-dip
residue technique. Test insecticides included compounds
widely used in commercial filbert orchards, namely,
carbaryl, diazinon, endosulfan, phosalone, fenvalerate and
oxydemetonmethyl. Aphid samples were collected within a...
Anadromous fish populations in the Pacific Northwest have
undergone substantial change throughout the past century.
Historical periods of over-harvest and the construction of
numerous dams throughout the region have contributed to declines
in the runs of naturally spawning stocks. Management efforts to
rebuild fish populations have focused on the restriction...
By 1976 extended fisheries jurisdiction had been
declared by most coastal states and territories of the
world. The new regime of property rights was expected to
affect seafood production costs which, in turn, could impact
on seafood trade and the competitive positions of
producing countries. In theory this policy should...