Decomposing Body Odour Mimicry

Olfactory stimuli associated with decomposing bodies is even exploited by plants. Certain plants of the Araceae family use mimicry and deception by releasing compounds similar to those associated with decomposing bodies to lure carrion insects such as blowflies and carrion beetles for pollination (Kite and Hetterschieid1997; Stensmyr et al. 2002). Semiochemicals associated with decomposing bodies are produced by the Mediterranean flower dead-horse arum, Helicodiceros muscivorus (Araceae: Aroideae) to trick the carrion flies in favour of the plant. This flower lures blowflies to act as pollinators by emitting dimethyl sulfide, dimethyl disulfide, dimethyl trisulfide, and dimethyl trisulfide derivatives (confirmed through GC-EAG experiments), which are also found in decomposing meat. The flies are thus enticed and trapped into a floral chamber that surrounds the female florets (Stensmyr et al. 2002). Other factors such as the appearance of the plant - the flower is said to resemble the anal section of a dead mammal - and the pseudo-thermogenic properties of the plant are also key factors in the fly's attraction to the plant (Stensmyr et al. 2003). Circadian activity may also play a role in fly attraction as the odours are only emitted between sunrise and noon. GC-EAG tests also showed that female C. vicina, L. caesar, and other Calliphoridae species were attracted to these compounds and were not able to discriminate between decomposing meat and the flower through olfaction alone (Stensmyr et al. 2002).

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