#spiderzrawesome

They don’t have venom at all and their mouthparts are too small to even pinch human skin. They’re mostly scavengers and sometimes hunt very small bugs/insects. They break their food/prey down through the use of enzymes in what amounts to their saliva. 

Harvestman info!

I am so, so sorry it took me this long to reply to you! I make no excuse, only offer my sincerest apologies.

Yes, when Phidippus audaces are young, their spots are mostly orange. They get lighter with each molt, until maturity, when the spots are white or cream coloured. Sometimes, there are variations in both colour and pattern, but in general, the spots become lighter as the spider ages.

I believe there are 4 to 6 molts for the average Phidippus to reach maturity. This excellent photo details one male spider's journey into adulthood. Here is another set of the same species, showing five molts. 

Here's a site with great photos of various instars. If you're familiar with the species, and have photo references, it should be a matter of matching up patterns to determine which molt the spider is on. Otherwise, it's very tricky. The best thing to do is be familiar with the spiders that occur in your area. Once you have a good catalog, you'll know for what to look and research when you come across a potential juvenile.

And an "instar" is a developmental stage that arthropods have. It's basically what occurs between molts, the state the spider (or whathaveyou) is in before they shed their skin again. It's a good way to keep track of tarantulas, especially.

I want to apologize for taking so long to answer this- I had a lot of research to do and then I got distracted with other things.

That said, this was not easy to answer. So I'll go through and list the facts, first. Araneid spiders (orb-weavers) have some of the worst vision. From Barth, via Land and Yamashita (1985), "Orb-web spiders (Araneidae), according to prevailing opinion, have a poorly developed visual sense with low spatial resolution and with lenses that cast a sharp image of a viewed object onto a plane outside that of the visual receptors."

Agelenid spiders (funnel weavers) see better than the orb-weavers, but not nearly as well as spiders that are active hunters; ones who don't rely on a web for food. Salticidae, Lycosidae, Thomisidae and Sparassidae are some of the families that have the best vision, because they’re the aforementioned active hunters. Though they remain largely stationary and use a web to ensnare prey, Deinopid spiders (net-casting spiders/ogre-faced spiders) also have excellent vision, during both day and night.

But you asked what kind of eyesight these animals have. As I stated, orb weavers and funnel web spiders don't have the best vision, instead relying on their webs, vibrations and chemical receptors to experience the world around them. So I suppose the best way I can answer is by telling you Araneid spiders see poorly and Agelenid spiders see about average, as spiders go, anyway.

Do jumping spiders see better than hawks? Hawks have large eyes and binocular vision that is suited to distance. They have the best eyes in the animal kingdom- up to eight times sharper than humans! So, no, a jumping spider cannot see better than a hawk, even taking into account the difference in size and the functions the Salticids extra eyes preform. 

Can a Salticid see better than a cat? Since jumping spiders are so much smaller than cats, and see the world differently, it's a tough comparison. While their hunting behavior is remarkably similar, cats do have superior vision to jumping spiders.

And where cats see better than humans (200 degree field of view to a human's 180), humans still see about five times better than a Salticid.

Salticids do have the best eyes in the invertebrate world, though. They see in three dimensions, can judge distance and some (Portia spp., as studied in the 'Eight-legged cats' paper) can even tell the difference between insects and spiders and even spiders that carry their eggs versus ones that do not!

Further Reading:

Links about Salticid vision

Tree of Life- Jumping Spider Vision

Wired- Spiders Hunt with 3-D Vision (this article does mention some... unpleasant means of finding about Salticid vision. Read with that in mind)

Wikipedia- Jumping Spider Eyes (cites enough sources that I feel comfortable using it)

Wikipedia backs up human eyes being 5 times better than Saltcid's.