Question
my sqaush and pumpkins have powdergray bugs on them that turn brown when they mature there are thousends of them i grow organic

Answer
Ken, what you are experiencing is an infestation of squash bugs, otherwise known as stink bugs.  The moths lay their eggs in late spring on the underside of the squash leaves.  A few days later they hatch, and eventually mature into what you have discovered.

Mature squash bugs are extremely difficult to control.  They seem immune to most pesticides.  Most experts will tell you that the only real control is handpicking them and depositing them into a bucket of soapy water.

Some things to try include garlic spray or a mixture of 1 tbs. lemon ammonia with one tbs. of dishwashing soap to one gallon of water.  Neither of these will harm the plant, so spray liberally every other day for 2 weeks.  Other controls include rotenone and pyrethrum.  These should be
sprayed every three days for two weeks.  They are non-toxic to humans and can be sprayed right up to harvest.

Next year, I would advise covering the young plants with reemay.  Reemay, otherwise known as floating row covers, is a lightweight, fleece-like material which protects plants from light frosts, pests, and insects, while still letting in water, fertilizer, and sunlight.  Just remember to
remove the covering once the plants begin flowering for pollination. Reemay can be purchased at most garden centers or nurseries.

I hope this helps.  Please write again if you have any more questions.

Regards,

Mike