I live in Albuquerque in the valley bordering the Rio Grande. This area has been cultivated for squash for 400+ years. Squash bugs probably arrived here a year after the first cucubit. They take no prisoners. I am the only person I know who can plant zucchini and not have enough fruit for myself much less the neighbors. I continue to plant squash (though I never get any) because it diverts the bugs from the melons and cukes but I would really like to figure out a way to defeat the wretched bugs.
I have tried:
1. Planting after July 1 (no dice---they moved in wholesale, getting not only the squash but the pumpkins).
2. Daily applications of insecticidal soap, Pyola, and various other contact nostrums. This will keep numbers down for a bit but eventually, the bugs triumph and it takes an hour a day to spray the undersides of all the leaves. I have a big garden.
3. Rotenone and pyrethrins. See above.
4. Hand picking all the eggs while squishing every bug I see. Although there's a certain satisfaction in hands-on annihilation of the enemy (and the ants love to haul away---and presumably eat---the fallen), the bugs defeat me one to two weeks after the squash begins to set fruit.
5. An experiment in the front yard, far from my garden, where I actually broke out the Carbaryl on my carefully segregated patch of crookneck. The bugs LOVED the stuff. They seemed healthier and more voracious than the ones in my garden.
I have not tried covering the plants with a barrier because I cannot for the life of me figure out how the bees are gonna pollinate the plants. Getting up at 6 a.m. to allow bees limited access (and I have no reason to believe the squash bugs get up later than the bees) is really not an option for me. Ideas??? I like squash. Help!