Im wondering, (after trying some thought provoking awesome Critical Cheese blended w Purple Malawi), that there are 'invisible' or 'undetectable by humans' terps and terpenoids..
Every sense we have has a range, a visible spectrum,
Light? we see a fraction of the light spectrum..
Sound? we hear a fraction of the sound spectrum
Taste? same -limited taste..
Touch? -limited
Smell? probably the same..
Lets say you place ripe fruit/other flowers like roses in proximity to blooming herb to supply 'base' terpenoids which gets used to make terps for those plants sharing the space..
Youre thinking probably, "Ziggs, dont recharge your Crafty vape for a few daZe and give that 'mad mind' of yours a break".
maybe, Im not 'mad'
I like the question DrZiggy and I believe you are on track with your thoughts I was reading about Methyl Jasmonic acid and how it has shown to increase trichome production in plants by triggering the plants defensive measures and came across this.
Inducible defensive responses in plants are known to be activated locally and systemically by signaling molecules that are produced at sites of pathogen or insect attacks, but only one chemical signal, ethylene, is known to travel through the atmosphere to activate plant defensive genes. Methyl jasmonate, a common plant secondary compound, when applied to surfaces of tomato plants, induces the synthesis of defensive proteinase inhibitor proteins in the treated plants and in nearby plants as well. The presence of methyl jasmonate in the atmosphere of chambers containing plants from three species of two families, Solanaceae and Fabaceae, results in the accumulation of proteinase inhibitors in leaves of all three species. When sagebrush, Artemisia tridentata, a plant shown to possess methyl jasmonate in leaf surface structures, is incubated in chambers with tomato plants, proteinase inhibitor accumulation is induced in the tomato leaves, demonstrating that interplant communication can occur from leaves of one species of plant to leaves of another species to activate the expression of defensive genes.
So what this basically is saying is that the compound Methyl Jasmonate and Ethylene are VOC's that can be released into the atmosphere and cause effects on other neighboring plants. What these compounds do when received by another plant is they simulate an insect attract and the plant will respond by increasing terpenes, trichomes and essential oils. I've been really curious about how this would apply to cannabis but it is confirming your thoughts by saying that in fact plants do sense "plant pheremones" that are released. Not sure if they can create new terpenes in the receiving plant, but from the studies I have read it can increase the terpene production of what already is present in the receiving plant. Very interesting stuff