Spiders eat astronomical numbers of insects | Hacker News Reader

Spiders eat astronomical numbers of insects

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104 pointsdeegles60 comments

I have anecdotal experience with this. I used to have dense native plants in my yard. My local municipality made me cut them all down. The mosquitoes, specifically the invasive Aedes species seemed way worse without the lattice of tall native plants that provided both platforms for jumping spiders and infrastructure web based spiders. My tiny yard created so much spider-space for arachnid and other predators. Too bad I was punished by my local municipality for being so arrogant to want grow native plants. I have massive photographic evidence to this effect. See here: http://opilionesman.blogspot.ca/2017/05/i-wanted-to-share-so...

Hello fellow DMV resident. Where in the area do you hope to find a municipality more tolerant to basic biodiversity? Out towards Harper's Ferry, perhaps?

Wow, sorry to hear that. Beautiful photos, sounds like an amazing yard. Did you move somewhere you can have a wilder lawn?

Out of curiosity, what did this look like from the street?

What a sad ending. I used to live in Texas where the houses were all very similar, with mono-culture yards that required constant water, fertilizer, and mowing.

I now live in the Bay Area, Oakland specifically, and something I've really come to appreciate here is the lack of any sort of ordinances like you've run into. In fact, having a green grass lawn is frowned upon for all the environmental reasons you call attention to. I bought a house in the Oakland Hills last year and we're surrounded by large trees, native grasses, ferns, and dozens of native or drought tolerant flora. Few of the yards are fenced in, which allow wildlife like deer, foxes, turkeys, coyotes to roam freely between the houses. The trees support dozens of different species of birds. And while there are tons of spiders too, very few mosquitoes. And this is still in a city! And do I have to water it? Fertilize it? Mow it? No. I have a crew come through once or twice a year to clear out overgrowth (required for wildfire safety) and that's all the maintenance that's required.

I really wish more places in our country would allow native plant life to thrive around our cities, we'd all be better for it.

You should see all the empty lots where the houses burned down long ago in places like Flint. The lawns aren't mowed in the summers so they look like wheat fields and wildflowers grow like crazy.

It's a traffic hazard as the intersections have no visibility, nobody will mow because people dump junk in the empty lots and you'll hit bricks or metal and ruin the mower.

> It's a traffic hazard as the intersections have no visibility

That does not sound like an argument against overgrown lawns but for speed limits and road designs that discourage fast driving. Here residential areas intentionally curve their roads so people can't drive fast because visibility is not all that great around house corners anyway.

Welcome to the east bay hills! May I suggest a fun alternative to a standard gardening crew to clear your extra growth:

http://goatsrus.com/contact.htm

From the sound of it, your yard/land is a great fit for their services :)

I know some neighbors use them. Trouble with goats is they don't discriminate much about what they eat, and we do have some things in the garden we'd like to keep :)

I thought Texans love FREEDOM and SF was considered the epitome of environmental regulation -- but it seems in some areas the shoe is on the other foot!

Freedom from the big government, tyranny from the small.

In Austin, xeriscaping is usually welcomed.

And in our Firewise neighborhood, we give people a list of native plants that are more fire-resistant, in case they want them. We also do Home Ignition Zone inspections on a volunteer basis, to help them identify their biggest risk factors.

You should disguise it as manicured landscaping with a few cheap features thrown in to appease the tasteless mulch volcano lovers.

This happens in foreshore native zones: attracting mice and rats attracts their predators: snakes. Though, cats too. Probably only happens when plants reach a certain density, but how to control that?

I live in Australia, and people always freak out when they see me post pics on spiders around our house on Facebook etc. "Ozzie critters kill you!" they say.

However the most common spiders in our house are Huntsmen spiders [0]. As big, frightening looking and FAST as they are, they are completely harmless to humans, and they eat a lot of the larger bugs around the place. We even give them names as they tend to hang around for days/weeks.

We do have poisonous spiders, but they are rarely found indoors, and I know the places to avoid outdoors where the Redbacks and Mouse spiders live.

[0] - https://www.youtube.com/watch?v=r011GRdai8Q (arachnophobe trigger warning)

Why would anyone be afraid of poisonous spiders? Do they crawl into your mouth while you are sleeping?

Ah, you probably mean venomous?

What exactly do you hope to achieve by this kind of needless pedantry? You said yourself that you understood they probably meant venomous, so it's not as if the comment wasn't clear.

I've noticed a huge uptick in pedantic comments like that on HN.

Because actually I did't understand until I was about to post the comment with just the first question, at which point I thought to myself OP might mean venomous!

There are poisonous animals out there that you really should not eat! But for the most part people aren't afraid of eating poisonous things (it's usually too late to fear).

you had me at 'mouse spiders'

Haha - Though they sound like "mouse eating spiders", they are far from that, being only about 2 to 3 cm across (less than 2 inches). And they look quite cute to boot, apart from those huge pincers. [0]

They tend to burrow and hide in garden beds etc. and avoid humans where possible, but often during their mating season, or after we have dug up a garden bed to plant new stuff, we see the odd one on the driveway or in the carport. As long as you can see and avoid, it is all good, and worst case, if they give you a nasty bite, it will be painful, and may make you sick for a day, rather than fatal.

[0] - https://australianmuseum.net.au/mouse-spiders

I do suffer from arachnophobia, but I also live in a place where opening a window at the end of a hot summer's day means inviting a Zerg rush of insects. (Okay, there's probably places that are way worse. I feel for those people)

Vibrating spiders (https://en.wikipedia.org/wiki/Pholcidae) are happy to eat anything that gets caught in their webs. In Germany, these are THE kind of spider you will most likely to find in a typical apartment. And they do not discriminate between insects and other kinds of spiders that happen to walk in.

The fact that none of the spiders I am likely to meet where I live (Germany) is even remotely dangerous to anything that is not an insect probably helps.

But still - at some point, the number of insects these beasts kill before they get annoying outweighs the terror I feel when one of these crawls across my desk.

Yea when I lived in a poorly insulated half basement, I'd keep all the spider's alive on the corners and edges, and they killed a prodigious amount of bugs. Was hard to remove all the carcasses without destroying the webs above.

If it's not harmful to you I would suggest picking one up. I was in your camp and picked up a harmless spider, better now.

This is simplistic but a quick anecdote to hopefully push you like I needed pushing to get over my irrational fear.

Exposure therapy seems to be pretty solid science. https://en.wikipedia.org/wiki/Exposure_therapy

I am aware of that and have considered it. But it does not affect my life very much, so the pressure to deal with it is not high. Vibrating spiders tend to live in places where they are not disturbed, and they do not move around a lot, so we do not cross paths very often.

I thought picking it up was a bit extreme until I realised krylon was talking about daddy long-legs spider.

Fair enough. If there was a pick-uppable spider I think that would be it.

Those are cellar spiders, not daddy-longlegs (AKA harvestment AKA opiliones; which aren’t spiders, as they only have one body part). They do look similar though! I like to say that I’ve got opilionophobia, and just happen to be afraid of spiders and some other insects that look like daddy-longlegs.

As soon as I read your first sentence I immediately thought "I wonder if they live in Germany".

Having lived there a few years I was astounded at the lack of fly screens, given that there are just as many mozzies and other bugs flying around there in summer as there are back home in Australia. But in Oz, pretty much every window on every house has a fly screen.

I think I saw two or three in my entire time in Deutschland. So I know they're available, but I don't get why they're so unpopular.

Mmmh, I never really thought of that.

FWIW, I do have a fly screen on my bedroom windows. At work, we have at least one window with a flyscreen in every office. But yeah, all in all, they pretty rare around here.

My dad lived in North Carolina. He called it "bug pressure," which is when the bugs are dense enough to resemble a gas.

I wish birds would eat astronomical numbers of spiders, or at least black widows. For whatever reason, black widows are a plague in my micro-area. I could walk around the outside of my house tonight and find 8 or 10 easy. Big ones too. Always have to take extra care around this place.

Anyway, people tell me chickens eat them, but I don't really want to keep chickens.

- You wish birds would eat them.

- You get birds that eat them.

- You don't want to get said birds.

- You get foxes that eat them.

- You get dogs that eat them.

- Wolves, hyenas, lions.

- Lions die in winter.

- The wheel of the seasons

- You run the dogs over

- Ant lions have their way

In Costa Rica I saw a few houses deploy some type of lizard around the property to take care of spiders, mosquitoes, and scorpions. They appeared just pet-like enough not to freak out most visitors, were anti-social to humans, and seemed to have a voracious appetite for pests.

Here at Brazil it's mostly lizards that eat spiders similar to black widows, not birds.

I suspect they also eat a lot of other spiders as well. I was looking at a couple of spiders on the ceiling the other day. A big one and a little one. Apparently nothing was happening, but as I watched I noticed the big one was slowly circling around and in towards the little one. Then at a certain point it suddenly started moving fast. But the little one was obviously aware of the danger. It made an "I'm out of here" rapid descent on silk. Until that point I thought the little one was an insect actually (so small I couldn't count legs at a distance). Another day in the life, nature red in tooth and claw. I like being at the top of the food chain.

I was curious if you could use them for pest control and it appears the answer is "kinda". The biggest issue appears to be that most spiders are pretty indiscriminate eaters, so while they'll happily eat crop destroying insects, they'll also eat bees, etc.

A shop I found - https://spiderpharm.com/store/#!/Live-Spiders/c/11175143/off...

I got one of those new LED flashlights and went to test it out at night. I used the trick my dad taught me of putting the light at my temple, so the light would be eye level. This way animals with reflective eyes would be visible if they are looking in your direction. Checked the dogs and sure enough a couple of glowing eyes.

Next I walked into the lawn and saw that dew drops covered the grass. A nice sparkling effect. After a bit of walking around a bit more and investigating some other areas, I noticed the grass was not really wet - the sparkle was spider eyes reflecting the flashlight! Must be 5 - 10 spiders per sq foot, everywhere I looked. Very small with no webs, but easily believe these numbers.

I live in Hong Kong. I’ve actually caught and released jumping spiders into my 6-yo daughter’s room, to clear the booklice on the ceiling. My daughter doesn’t mind the spiders. I have taught her enough about insects and spiders that she’s not afraid of them. We even raised silkworms and kept a huntsman spider as pet.

I always leave spiders alive in my apartment. I've lived in two. In both cases, when I first moved in I had bugs. After leaving spiders alive, I then had almost no bugs.

I was vacuuming spider webs in my house today because I had guests visiting which always triggers a flurry of cleaning.

I avoided vacuuming the spiders themselves though, those little dudes are helping us out.

Well, if you leave your vacuum hose lying flat on the ground after turning it off, you can have a fun time watching the spiders march out after a while, should you accidentally catch a few.

I remember reading a question about this somewhere, where it was stated that because of the massive turbulence inside a vacuum, there was very little chance of a spider surviving something like that!

I believe you, but I've actually seen it with my own eyes. Quite probably the survivability depends on the type of spider...

When I find a spider in my apartment, I usually leave it alone so it can kill off other pests.

As long as it's not bothering me, I usually don't bother it.

Clearly this means the solution to our declining insect population is predator control. A problem we created by spraying insecticides, we will solve by spraying arachnicides! It's perfect.

Much Love,

Dow Chemical

Where I am we have a huge amount of wolf spiders and parson spiders. Both of them have (from what I've heard) pretty painful bites[1] so I like to keep them out of the house but I almost never kill them. I usually just let them outside.

I'm fairly sure it's not a coincidence that I almost never see a mosquito even though I live near a pond.

Now if only we could train them to eat deer ticks...

[1] Like a bad bee sting. Not dangerous unless you are allergic (possibly?).

Dad always gets pissed when mom tries to remove spider webs in out boat - it’s the webs that keeps it flies-free.

That said, last year we had ant infestation. Dad tried everything including chemical agents until we found there was 1 kilo of sugar in a paper bag. Nothing was stopping ants getting there. Removed the sugar and ants were gone days later.

I used to kill them, and all manner of other insects. Not sure why. As I've gotten older I leave them alone or throw them outside the house if my girlfriend sees them.

I guess this is one more reason why I should do that. If only they could eat up all the damn mosquitoes though.

spiderbros

Also I really hate that pets, particularly cats, kill a big amount of spiders, birds, lizards, bees, and all those very useful creatures, (useful compared to pets). With 1 billion+ pets, it's an issue, and many cats go outside. It's like a 5% larger human footprint, when you consider also all the care/food brought to them, completely unnecessary

I once had a neighbor constantly losing track of her outdoor cat, and would wander around calling the cat by name for an hour. I relayed this obnoxious story to a nature photographer, he said kill the cat, as in shoot it. I said no. He said to buy him a plane ticket, and he'll shoot the cat.

A family member is a veterinary technician, and says outdoor cats do a lot of damage, and the cat themselves lives a shorter life. Outdoor cats should be considered the same as any stray animal or varmint and picked up by animal control, but I guess it's impractical for whatever reason.

Anyway, cats should be kept indoors, and outdoor cat owners are ignorant.

Unethical Life Tip

Catch the cat and release it 50 miles away

What country are you guys from that the phrase “outdoor cat” is a thing? Where I live, the uk, that’s just a cat; “indoor cat” would be the notable, unusual state.

Any cat kept in a flat above ground level is pretty much an indoor cat. In some countries, most people don’t live in houses, but in flats.

If you want to know why Animal Control would rather just leave the stray cats alone, look up "Pinky the cat" on Youtube. ;)

Upvoted.

Cats are menace. They kill a billion birds yearly. IIRC, 2/3rds of cats are feral. Cat owners who let their cat outside are perpetuating the problem.

My preferred solution to the cat problem is coyotes.

Source: Volunteered at Audubon for a decade.

For more happy thoughts, many of the ones that only eat inside dine on food produced by human slavery:

e.g. Nestlé (Purina) admits slavery in Thailand while fighting child labour lawsuit in Ivory Coast

https://www.theguardian.com/sustainable-business/2016/feb/01...

More like, gastronomical

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