Invasive species and deer flies
For invasive species, monocultures of Japanese stiltgrass smothering all native vegetation on the forest floor are definitely a contender for least favorite.
I was expecting replies along the lines of humans, mosquitoes, chiggers, etc., but it is very interesting to hear about these invasive species. My personal least favorite invasive species would have to be Asian lady beetles, they are pretty prominent in the Southeast and, to my knowledge, have outcompeted a lot of native ladybug species. Generally speaking, yellow-rumped warblers (Setophaga coronata) are so unlikably common and if I spend another 10 minutes trying to track down the flighty bird in the bushes that ends up being another S. coronata I am going to lose it.
I love poison oak but man does it keep me from getting closer to cool stuff sometimes. Its remarkable shape-shifting ability doesn’t help.
Other than that Oxalis pes-caprae and the invasive broom species have been particularly on the front of my mind lately with their blooming, pretty but so frustratingly pervasive.
Ticks, mosquito’s, not a fan of invasive species but deal with it, and humans behaving badly. People don’t bother me until they do stupid stuff. Sadly they do that stuff way to often.
Cherry laurel. Horribly invasive bush here that does almost nothing for the local wildlife (other than the generalists which could be pollinating anything else anyway). Seeds readily and the plant readily layers so it creates large shady thickets that shade everything else out and prevent regrowth of anything but it. Rhododendron ponticum is similar but way less common in my area, so I haven’t learned to hate it as much yet.
For some reason it can still be sold readily in garden centres and is still widely planted. Genuinely unsure why when it’s so nasty (and let’s be honest, in a garden, mighty tacky). It’s invasive over in the States too where it’s called “English laurel”. God knows why - we don’t want it either!
When you get one particular “spam moth” on a sheet. You hope they are calm but many times you get the larger species that bounce around and disturb things you are trying to photograph.
Poison Ivy, Cockroaches, & mosquitos
Angry humans. Especially when they think that I am taking photos of them and I have to explain for 5 minutes about how I took a photo of a bird and show them my whole camera roll just to prove that I wasn’t photographing them. Also yellowjackets since they someone always sting me, and the dreaded ticks(especially Lone Star). Sometimes Aralia elata and Smilax rotundifolia can become dreadfully annoying.
Probably tabanids and biting midges. So hard to take macro pics with them fighting to drink from your veins. The midge bites makes my ears swell up like sausages and they get into my hair, and the tabanid bites are darn sore. Somewhat counterproductive to douse yourself in insect repellent when your main aim is getting close up with insects…
Chinese privet and deer flies.
Probably dogs. Their tracks clog spaces where other prints could be visible on trails, they usually scare away other animals, they disregard the boundaries of trail vs. forest…
And I’m allergic to dogs. I may be biased.
Yess, dogs are such a nuisance, both to the wildlife and the people wanting to observe it!
Personally my least favourite might be the invasive Rubus species in the PNW, the most common of which at least around here is generally thought of as Rubus bifrons (I know there’s some debate about the actual sub-genus taxonomy of the invasive brambles around here). It grows all over the place and smothers other plant life. There are lots of introduced species around here, but the Rubus brambles are the ones with the most dramatically visible impact on the landscape, at least in the places I visit.
Plus they’re stabby. I’ve cut myself on them a few times.
Close second least favourite is the Hedera ivies, for the same reason of being highly disruptive to the landscape. At least they don’t stab me, though, and they’re less ubiquitous.
Interesting how many people cite people and dogs–I get frustrated too sometimes. But, to be fair, I have discovered that many times, if I have to step aside on a trail for people and/or dogs, I’ve accidentally discovered something really cool that I wouldn’t have seen had I not had to stand aside. People more than dogs mess up my photo opportunities though. They just plow through no matter what. I have more patience with canines because I just like them better. :)
You mentioned everything but the actual biggest dog problem: their poop being everywhere.
I’ve never seen cherry laurel grow invasively where I live but I loathe it anyway because it’s ubiquitous in the countryside, it’s treated as the only hedging plant in existence.
Native mixed hedges are frequently torn down and replaced by the same long, boring cherry laurel expanses trimmed in the shape of a square. The only beneficial elements those plants offer to local wildlife, the flowers and fruit are destroyed by the tight and formal clipping, making them as useful for nature as plastic barriers.
My neighbors have cherry laurel hedges too, and once they’re done trimming them in the typical nauseating square shape they have the habit of burning all the branches and leaves on the ground, inundating my garden with noxious smoke.
At least where I live, this isn’t a huge issue. There’s certainly some dog poop, but most people pick up after their dogs. I see way more deer poop, for example.
Yellowjackets are a particular problem in the last couple years since I started having allergic reactions to them (hives). I will not stop walking around in the woods but the yellowjackets are very hard to predict. The last two times I was stung I did not see a nest and it was a single wasp stinging me randomly. I wasn’t being careless or anything. It just came out and stung me. No warning. Not sure what people do who are out miles on a trail and this happens, as EpiPens are only temporary fixes. I have gotten on immunotherapy and I hope that minimizes my risk to a sting reaction but there is only one way to find out!
I would rather lie down in a deer scat than go close to dog poop, there’re hundreds I see each day in different stages of decomposition, often the size of a human poop, often hiding under leaves, spreading with spring water, etc., I’ve seen like two people with dog packs in my life, we had a set up on my house with those, but they just disappeared in a day and were never refilled, anyway, nobody cares, but if you go off path it’s a mine field.