Since I've put my trees outside last month I've been noticing these white spiders I've never seen before. They appear only on my lemon trees and are either immobile or moving very slowly. Sometimes they sit on flowers as if they're waiting for a pollinator to arrive. Does anyone know what type of spider this is and if it's harmful to the tree in any way? Here's a picture I just took:

I don't think it is a spider--I think that is a seed of a type like a dandilion that got trapped in a spider web. I see similar seeds trapped in webs on my trees.

I edited the picture to put a red circle around the spider, should've done that at the start. It's true that it's hard to see on the white flower.

The creature on the flower looks very interesting. I've never heard of spiders being plant pests.Can they possibly be feeding on pollen or nectar ???????
More likely they are attracted to prey visiting the flowers.If they dont seem to be hunting, perhaps the scent is confusing their mating behavior, white spider, white flower, intoxicating perfume, strangers in the night etc etc.
You will just have to monitor the blooms and try to determine if the spiders are causing any excess shedding of flowers or damage by their activity.

I recall from biology that all spiders are carnivores. If it is really a spider it will do no harm. (count the 8 legs, insects have 6 legs)

Helix

That looks cool! I play with spiders when I was a kid. I'd hunt for them, including a few of the venomous ones with proper equipment. I used to sell the venomous types to researchers.

And the good news is that AZ41 will not kill the real spiders, but the spider mites on the other hand.... let us just say they'd be in trouble.

And here's a general statement about sprays with low chain oils that are water soluble. The real spiders will have nice sets of tiny hairs that even the spray solution with sticker properties won't be able to stick around them and so they will survive the spraying ordeal. Smaller insects will be easily encapsulated with the spray droplets and if droplets contain oil, the smaller insects can suffocate.

In my greenhouse, I never kill spiders. As Helix points out, spiders are predators, and therefore helpful in controlling the pest population. Most of the spiders in my area are black jumping spiders, with a white dot on their head. Like SGF, I also see pure white spiders from time to time in the greenhouse. Of course, every so often, there will be the large Wolf spider, and and occasional Black Widow. - Millet (1.359-)

I see what you are talking about now--if it is a spider (8 legs) it is probably there to ambush prey coming to the white flowers--pretty good camoflage.

Looks like a spider in waiting to me. Seems like I remember that spinders sometimes become lighter in color when they are ready to molt, and that the skin left after molting is often white in color.

Ned

I believe it is a Crab Spider. Tends to lurk in flowers awaiting its prey.
This photo is from the 'Wild about Britain' website.

Mike

Great picture!

That's the one! They often sit with their front legs pulled backwards and bent forwards just like a crab, ready to strike. I haven't seen them catch anything though, my lemon flowers don't get a lot of visits except from the occasional bumble bee wich is probably too large for the spider to catch.