Is it common for LWers to have irrational reactions to bugs and spiders?

It is common for humans, LW or not, to have rational (or maybe arational is more accurate?) aversions to bugs, spiders, snakes, and other critters that could poison us in the environment of evolutionary adaptedness. Overcoming this through learning and exposure is commonly required to get over the fear.

You need at least one person to assist you in constructing your controlled setting. Maybe you could use a local pet store as your controlled environment.

Exposure therapy is the way to go, to desensitize as you mentioned. Here is a plan

Good luck

This has helped me stamp out the last vestiges of my arachnophobia. It's a window with a realistically moving spider that follows your cursors. The reason it helped me is because I knew I could close the window with a single click at any time and the fact that I had complete control over its movement. This amount of control gave me enough self confidence to deal with real life spiders.

I have a phobia of certain arthropods, especially of big ones that fly. Hornets and bumblebees are the worst. Dragonflies aren't easy too, but at least they rarely fly inside a room. Somehow the fear is connected to the label insect, so after I learned that spiders are not insects, my aversion to them has weakened (but not disappeared completely). I could rate arthropods on a scale measuring my fear:

1. Crustaceans (except woodlice): no problem at all, I can eat them.
2. Anything smaller than 5 mm in length (other dimensions play a role too, the smaller the better): I can touch or crush them.
3. Woodlice, centipedes, silverfish, harvestmen, smaller butterflies, caterpillars, ants, small beetles: can touch them, but crushing them makes me feel uneasy. Perhaps scorpions belong to this class.
4. Most spiders, flies, moths, big butterflies, big beetles, solifugae, true bugs: I try to avoid touching them at all.
5. Wasps, bees, dragonflies, cicadas, anything else which is big, flying, noisy or hairy: when one is near, I can't concentrate on doing anything. Being closed in a room together with few such beasts and no weapon (like a newspaper) is a nightmare.

I don't have any phobias but I'd be interested to know if anybody has managed to overcome fears/phobias with greater knowledge. The closest experience I've had is that I started to enjoy the taste of mushrooms (which I previously found repulsive) after taking a mycology class. I realised that what I found repulsive about mushrooms was partially due to ignorance (they're an odd food to categorise). Insects and spiders are odd, difficult to categorise beasts too, so perhaps knowledge would help in addition to exposure.

This think jmed's link has the right idea.

The key to desensitization, in my experience at least, is to be able to force calmness during the whatever is causing the nervousness/stress/fear durring exposure. Start off with the smallest stimuli that invokes fear and do your best to be calm and relaxed. Deep breathing at first and latter activities that require some attention like reading, cooking, stretching, etc. After the current level of stimulus does not interrupt these activities increase the level of stimulus and repeat.

If no progress is made in a month I would recommend continuing the effort, but shifting focus to conquering smaller fears first. Take advantage of real life situations that make you nervous/stressed/fearful and do your best to calm yourself. Do scary/action movies get your heart pumping? Go to a movie let yourself get wrapped up in the movie and then try to calm yourself down.

actually what you described as desensiztion therapy seems more like exposure therapy to me. this seems to be a good explanation of systematic desensitization. This works even in the relatively uncontrolled setting of being by yourself.

By attempting genocide.

My reaction isn't nearly so strong. If the spider is in an innocuous place and doesn't look jumpy then my first inclination is to look away and pretend it's not there. But I try to force myself to sit there and stare at it for a while, and scream out "SPIDER! There is a SPIDER! Spider. Spider." in my mind, or half-shout out it if I'm sure no one is around, to train myself to not flinch away from things that are unpleasant, and to keep my mind from getting into the habit of thinking that if I ignore something it will go away.

Be careful what you wish for. Humans are made out of biases. We enjoy roller-coasters because of the "irrational" fear they give us. We enjoy watching zombie movies because zombies are scary, when actually they are fictional entities, which, if they existed, would be less dangerous than a lot of "normal" humans or many real diseases.

Watching movies or riding roller-coasters could be seen as "irrational" in and of itself, just like playing the lottery. But what is left of human values if you get rid of all this?