No.
The only way to tell which Spiders in your area are seriously venomous is to learn to identify them individually. If you are in the USA all you really need to worry about are the widow spiders and the recluse spiders. There are a few widow spider species, and the ones that have bites that used to kill adults (before antivenoms were invented) are all glossy black with some red (sometimes an hourglass pattern) on the underside of their abdomens. There is only one species of recluse spider that you need to worry about, that is the "brown recluse," and it is a very undecorative brown color. People are always confusing one or another kind of spider with that kind, and the only way to learn to identify them is to get some good photographs and descriptions. Unlike the widow spiders, the range of the brown recluse spiders is fairly limited, so you also need to find out from your state government wheher your locality even has them.
If you live in Australia you already know about the Sydney funnel-web spider, and you probably know that it is a dull dark brown color. If you live in South America you probably know about the wandering spider found down there that can kill you if you manage to put your foot in your shoe after the spider has gone in and it bites you to keep from getting squished. It is mostly brown too, and certainly not yellow and black.
The spider that comes to mind when you say "yellow and black" is a beautiful spider that weaves orb webs and is never a problem for human beings.
Almost all spiders are venomous. Only a few spiders are venomous enough that they are potentially deadly for humans. All of the problem spiders are either predominantly black or brown. The black widow has a red hourglass figure on the bottom of her abdomen, and some other widow spiders have red markings.
The "Armored spider" or "Brazilian Wandering Spider" is brown, but at least its fangs are red. The Australian Funnel Web Spider is dark gray. The Brown Recluse and related Recluse spiders are all brown.
Maybe the spiders that need extra protection use bright colors to try to scare off predators, and the really venomous ones never had to bother with scaring anything off.
There are venomous tarantulas in Africa and India that are more brightly colored. They can make you extremely sick, give you horrible cramps for days, etc., but they haven't been proven to have killed anyone yet.
black of course the black witto i think i spelt witto wrong srry but the answer is black ok thx
usually red or black depens on what spider it is.
Red and yellow attract spiders
Arachnid.
is a snail an arachnid
yes, arachnid
A butterfly is not an arachnid
a spider is an arachnid.
Arachnid
arachnids is correct.
No. arachnid is another word for spider.
Yes, arachnid exoskeletons are made out of chitin.
A scorpion is an arthropod - sub species arachnid.
The scorpion is not an insect. but, The scorpion is an arachnid, and an arthropod.
"Name all the animals in the arachnid family?"