It gets that way in some wet years you just can't ride more than 50ks during Sept / October.
It's worst in the spring when the canola and wheat is flowering, it's a nice tasty mix of aphids and flies then, if you're lucky you'll even score the odd moth, butterfly or beetle.
I know guys who carry spray and cloth in there back pack.
I've been through them that bad just on dark you simply can't see where you are going, lift the visor and go blind because they just go straight in your eyes then.
We were driving a car going to Sydney once and I thought I'd broken the headlights, turned out the bugs were that thick on them they were too dull to work properly........bugs stories, mate I've got bug stories that'll make ya skin crawl.