Source of the chemical signal

For experimental studies of terrestrial salamanders, territorial markers have been obtained in a number of ways. A common and simple collection technique is to introduce individual salamanders into small chambers lined with a damp substrate (typically either soil, paper towels, or filter paper) and allow the salamanders to mark the substrate with secretions and fecal pellets (Tristram 1977 McGavin 1978 Jaeger Gergits 1979 Dawley 1984a Keen et al. 1987 Anthony 1993 Graves 1994). The length of time allowed for marking is variable, but a period of several days to 1 week are common. 

Simon and Madison (1984) attempted to distinguish between fecal pellets and 

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In both waves and unidirectional currents, the spatial distribution of odor filaments and odor-free water in a turbulent plume changes with distance from the source of the chemical signal (details reviewed in Koehl 2006 see also Weissburg, Chap. 4). For example, in a plume near the odor source the concentration gradients at the edges of odor filaments are steeper, the concentrations are generally higher,... 

For the two components of the carbonyl signal, see the text. Source Ref 46. Copyright 1999 American Chemical Society. 

The first step in a strategy for developing effective control of a pest by chemical ecology must be to determine if the species uses a chemical signaling system. If intra-specific signaling is shown to occur, the next step is to identify and synthesise the chemical agents utilized, with a view to successful application under field conditions. The most likely source of communication chemicals in amphibians is the secretions of the skin glands. 

Because the chemical signals (semiochemicals) are normally produced in minute amounts and diluted in the environment with a complex mixture of chemical compounds derived from a myriad of sources, the olfactory system in insects evolved as a remarkably selective and sensitive system, which approaches the theoretical limit for a detector. For example, it has been estimated that the male silkworm moth is able to distinguish within 1 s 170 nerve impulses generated by the female silkworm moth s sex pheromone from 1700 spontaneous nervous impulses [ 1 ], thus, operating on a remarkably low S/N ratio ... 

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