A little pollen poll

| 2 Comments

Hey team,

Things have settled down a bit and I've started work again on the great pollen challenge! I have ten locations for each of ~150 slides, and for each location I have been recording the count of pollen grains, as well as the number of species as best I can tell (I have also taken notes with descriptions of pollen in each location). My goals at this stage are to get better at recognizing pollen grains of the same species in multiple photos and to get a feel for the diversity and amount of pollen on the pollinators we caught. I'd also like to see if there's any pollen load size/diversity consistency within a pollinator species.

I have started looking at the male Melissodes sp. and so far it looks like about half of them carry no pollen at all, but some of them have multiple grains at each location.

My question for you is... What makes an insect a 'pollinator' in the context of this study? We are focusing on pollinators, and are not including insects that we caught but know are not effective pollinators (ex. syrphid flies), so there needs to be some way to distinguish between other effective and non-effective pollinators. I have thought about making a cutoff like, say, in order for an insect to be a 'pollinator' it must have one grain of pollen per location. That way insects that happen to be carrying one grain of pollen (total) but that aren't really pollinators wouldn't be counted as pollinators in this study. However, any cutoff seems very arbitrary. It almost seems better to include anything that we know carried pollen, even one grain.

But what about those male Melissodes sp.? If some individuals carry no pollen and others carry quite a bit, do they all count as pollinators, or just the ones that carried pollen?

If you have any ideas, please put them in the comments!


2 Comments

Amanda -- it seems premature to make a cutoff pollen load that defines an effective pollinator. You are right that any cutoff will be arbitrary. I think you'll want to get a more complete dataset (perhaps including identifying the Melissodes specimens to species) and then with more information you'll have some confidence about whether you want to make two categories or just rate species on a scale.

Good luck with the Great Pollen Challenge!

Stuart

PS Kate will soon start in on her microscopy. She will have 2 cents to share.

First off, kudos to all of you on the great work. I've found your site tremendously helpful, interesting, and informative. I cultivate my fair share of Echinacea (paradoxa, tennesseensis, purpurea, pallida, atrorubens, angustifolia), though not quite on the same scale as what you study (much to my chagrin).

Perhaps in the collection of the aforementioned "more complete dataset" the following factors/variables could be explored:

The peak pollination period / activity of respective Melissodes species (incl. temperature data if possible - I don't know if you log this variable in the field(s)).

vs.

The peak Echinacea pollen production (incl. any species related variances - I'm not certain if more than one Echinacea species is being studies or not; so this may not be applicable).

Further, this same concept could be applied to other pollinators (other than Male Melissodes) to cross-reference the respective peak activity of said pollinators with the availability curve/plot/etc. of Echinacea to pollinate.

Pardon me if I get any of the jargon wrong. I have been out of the game for a spell.

Best Regards,

MKJ

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