Drhoz! (drhoz) wrote,
Drhoz!
drhoz

Bounce, Bounce, Bounce, Everybody Bounce

Been learning quite a bit about spiders the last few days, as I put together my notes for the first presentation on pest groups for work. ( "Eight-legged Freaks - A Few Facts About Spiders & How To Control Them". BWAHHAAHAAAHAA - talk about given the monkey the keys to the banana plantation.)

For example, the Gummi Bears of the arachnid world, the jumping spiders. The family Salticidae are active hunters, stalking their prey with a visual acuity some tenfold better than dragonflies. Human eyesight is at best a fivefold improvement on that of the spiders. Which is quite impressive, and uses a variety of tricks such as a layered, vibrating retina. It still takes them a while to process what they've just seen, tho, because they have very tiny brains, after all. ( But at least they're not ground beetles, which are too stupid to run and think at the same time )

They're also wonderfully photogenic.

Australia even has "flying spiders" - jumping spiders with a pair of flaps down either side of their abdomen. Alas, it turns out that early reports of them using these flaps as gliding surfaces have never been corroborated, and it seems they only ever use them in mating displays. So now they're called Peacock Spiders.



photo by Jurgen Otto


I saw one of these once whilst on a field trip to the central NSW coast - amazingly pretty.

Another jumping spider - Bagheera kiplingi - is the world's first known herbivorous spider.

Bagheera lives in acacia trees in Central America. Acacia thorns have swollen, hollow bases. Glands at the base of the leaves ooze nectar,and the leaflet tips sprout nubbins of protein and fat call Beltian Bodies. All these growths are payment to the trees guardian ants, and the relationship between the tree and the ant is well known. But it's only recently been discovered ( by a student who got more interested in the spiders when he was supposed to be studying the ants) that some of the trees are also infested with these jumping spiders, that spend their lives dodging ant patrols and stealing the snacks.



At least 90% of their diet comes from these things. They also sip nectar (as do many spiderlings and crab spiders, it now turns out). They'll still mug the occasional passing worker ant for any ant larvae she's carrying, which suggests a plausible evolutionary route to their current diet.

"Baby? GET IN MAH BELLY! *pounce* WTF? This isn't baby ant! *sniff-sniff* hmm, still tasty tho... OM NOM NOM NOM"


Bagheera is also unusually social for a spider, with adult females standing guard over a creche of eggs and spiderlings. And for some reason females outnumber males 2-to-1.
Tags: blobs with no bones in, education even if you don't want it, pluunts, work - bleah
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