English: Sampling efficiency was scored using the reverse Cobra ranking (see text) for (A) Cat Ba, (B) Cuc Phuong, and (C) Vu Quang. Methods: BED: beating vegetation during the day; AEN: searching for spiders in the aerial stratum at night; LDD: searching for spiders on the ground during the day; LDN: searching for spiders on the ground at night; WIN: extraction of arthropods from sifted leaf litter using Winkler traps. Methods conducted during daylight hours are unfilled, methods conducted during night hours are black-filled. Methods targeting above-ground strata are up-pointing triangles, methods targeting ground strata are down-pointing triangles or a circle (WIN). Each WIN sample required two field hours; samples using all other samples were one hour each. High reversed Cobra scores indicate maximum efficiency of a method for contributing species to the inventory; low scores indicate sampling saturation for that method.