The plant's not going to invest such complicated mechanisms for a simple reason. Many other plants flower and seed in the same environments as hemp. Most pot doesn't have any thc in it. Therefore the thc isn't central to the plant's need. If a plant is covering seedpods with a sticky substance, it's to repel insects and other predators first.
If it wasn't, and the trichomes' function was other - some really necessary physiological function - they wouldn't be designed to self destruct on contact; they'd be designed to sustain some contact before collapse into goo.
If it wasn't, the uv screen would be incorporated into the sepals around each individual calyx. Much easier, much more rugged, much more efficient.
The mechanism of nature, when it's not in a bind, is to make anything as simple as can be arranged; and that which is complicated, perform as multiple functions when possible.
If the resin was designed to draw feeding animals, it wouldn't intoxicate them. In nature a fall can end a genetic line *snap* like that. All fucked up, flopping around to drunk to fight or flee is called Darwin award candidate. Being snake food, lizard food, anything with an appetite food is what being high means in nature - especially in an accessible environment like a pot plant. Things can climb it; there are no thorns - and eat the buzzed bugs & birds & beasts.
I grew up in a swamp. Later i completed two electronic technician trade schools for 2400 class hours of analyzing systems: their functions, their designs.
About ten years in the field working with all kinds of systems. Nature tends toward combined function and typically doesn't bullshit. If something's in a place - like the trichomes being pushed outward: they're there to be contacted first. If it's very sticky and non water soluble it's that way for a reason. If it's got intoxicants in it, those are there for a reason.
When
(1) it's built outboard when it would be lots cheaper inboard: there's a reason. For something to contact it before it gets to the seed.
(2)it's built incredibly sticky and completely water insoluble: that means it's meant to stick to something.
(3)it's got intoxicants in it: it's meant do deter consumption.
(4)it's thickest around the seeds.... duh.
(5)it's thickest around the seeds that are highest: therefore more likely to be encountered by flying insects, birds - well - it's not just a coincidence. When it's got more intoxicants in it higher up as well - the odds lean even further - as if they had to be - to indicate predation deterrence.
I know i don't post much and might seem to be oversimplifying to seem smart; no.
When many factors point to one thing: it just shouldn't be denied. The secondary functions of uvb absorption undoubtedly have to do with the wavelenghth of that light being able to catalyze chemical reactions that would otherwise be expensive.
Since massive quantities of anything in particular haven't been discovered being formed, this lends the idea that the chemistry is used to form chemicals that will be used locally; probably antibiotic/repellent functions are involved. This is after all a resin heavily vested in terpenes.
And incidentally, what's the last line we see written concerning terpenes in our local wiki terpene article?
"
Agri-chemical use
Research into terpenes has found that many of them possess qualities that make them ideal active ingredients as part of natural agricultural pesticides."
When a small globule of resin is found to contain many chemicals, it's not accidental. That plant's got people to do and things to see. It could just as easily fill it with any one substance as many.
Therefore the usage of the stalk caps is by default multifold. But the facts surrounding it's primary configuration: very sticky; contains intoxicants; contains other, terpene chemistry - a family associated with repellence; the fact the capped stalks are outboard - and, bristle around the fragile seeds -
This is too much to ignore. Additionally the seeds themselves - are specifically NOT designed to be eaten. Their thin shells make them easily cracked and rendered useless for reproduction. If the trichs were designed to draw predation for the function of spreading the plant's genetics, the seeds would be thicker.
Instead, as i noted, the trichs contain oils; are sticky; and intoxicants. At least two of these are well known, obvious repellents. The flavinoid/oil/other ingredients are there to DRAW initial attention: away from? That's right, the seeds.
Animal, insect, using sensory equipment, finds what first? Trichomes. Seeds are buried further below. No odor or tasty components, to the contrary they're very nondescript. They're not designed for intentional predation.
I've repeated myself i realize; most of the time i'm the L.A.S.T. person to suggest there's over analysis of a subject. However the overwhelming empirical evidence is as a repellent/deterrent with additional functions regarding the chemical reactions made easier thru usage of uvB.
Just sayin. When it walks like a duck, quacks like a duck, flies like a duck: it's a duck.