Chemical mimicry
Encyclopedia
Chemical mimicry is mimicry mediated via chemoreception (the chemical senses of smell and taste). Chemical mimicry may be used in combination with mimicry in other sensory modes (e.g. visual, auditory, tactile) or by itself. This sort of mimicry is less obvious to humans and thus has not received as much attention from researchers as other forms (like visual mimicry) have. Examples include spiders mimicking sex pheromones of moths in order to catch them, and plant mimicry of insect alarm pheromones which stops them from attacking the plant.
s is exploited by a number of parties. Because finding a mate is essential for a male's reproductive success, there is strong selection on males to respond to these chemical signals. Other signallers can benefit from mimicking these pheromones, for example bolas spiders, orchids or even other males of the same species (intraspecific mimicry).
Some plants have their seeds dispersed by ants, a phenomenon called myrmecochory
. Seeds have a nutritious attachment called an elaiosome
which functions as a food reward for the ants. In some cases the elaiosomes seem to chemically mimic insect prey. Brew et al. (1989) write that "[w]hile the nutrient composition of elaiosomes may provide the underlying selective advantage for ants in seed dispersal, specific compounds may manipulate their behaviour and maximize seed dispersal."
Examples
The attraction of male insects to sex pheromonePheromone
A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual...
s is exploited by a number of parties. Because finding a mate is essential for a male's reproductive success, there is strong selection on males to respond to these chemical signals. Other signallers can benefit from mimicking these pheromones, for example bolas spiders, orchids or even other males of the same species (intraspecific mimicry).
Some plants have their seeds dispersed by ants, a phenomenon called myrmecochory
Myrmecochory
Myrmecochory is seed dispersal by ants, an ecologically significant ant-plant interaction with worldwide distribution. Myrmecochorous plants produce seeds with elaiosomes, a term encompassing various external appendages or "food bodies" rich in lipids, amino acid, or other nutrients that are...
. Seeds have a nutritious attachment called an elaiosome
Elaiosome
Elaiosomes are fleshy structures that are attached to the seeds of many plant species. The elaiosome is rich in lipids and proteins, and may be variously shaped. Many plants have elaiosomes to attract ants, which take the seed to their nest and feed the elaiosome to their larvae...
which functions as a food reward for the ants. In some cases the elaiosomes seem to chemically mimic insect prey. Brew et al. (1989) write that "[w]hile the nutrient composition of elaiosomes may provide the underlying selective advantage for ants in seed dispersal, specific compounds may manipulate their behaviour and maximize seed dispersal."