Bees (family: Apidae) are important ecologically and economically as primary pollinators of many natural and agricultural systems. Given current concerns about declining numbers of bees, many ...

Systematic sampling is straightforward and low risk, offering better control. However, it may introduce sampling errors and ...

This is a preview. Log in through your library . Abstract A mobile phytoplankton sampling method, in which surface samples were dipped from the lake at 1/2-hr. intervals over circuits which could be ...