Are sickle mowers like Rouse making a come back to reduce the chances of blister beedles and weevils being compressed into the alfalfa through conditioner rolls? I always used haybine or diskbine type of equipment in Western South Dakota without a problem but blister beedles are starting to show up in the area. What is the best way to cut alfalfa now days to reduces the chances the beedles don't get into your hay? Alot of our hay goes for horse use and the beedles are so toxic to horses.
I have not seen an increased use of sicklebar mowers with alfalfa production; some of our farmers are now using disc-bines for its speed, but many still use the old style mower/conditioners. I have not heard of any increased problems with blister beetles. I have only seen one in over 30 years as county agent; that one was 20 years ago in some very mature, poorly managed alfalfa. The best way to avoid blister beetles is to properly manage alfalfa and mow on time. Blister beetles are predators, so maintaining good insect management will help. Regularly scouting the alfalfa field with a sweep net for insects will pickup not only alfalfa pests, but also any blister beetles.
In Missouri we do see some improvement in managing blister beetle by changing the harvesting equipment. Sickle bar mowers and swathers that don't crimp/condition the hay seem to let the beetles drop out of the hay after it is mowed. The first reason that we don't see a big switch to that equipment in our climate is that we seldom have the drying time to allow the hay to cure and be baled before the next rain. A second reason is that the leaves on alfalfa dry faster than the stems without conditioning and leaf loss can be a big issue and require good management to avoid. Remember that the leaves are the good part.
In your climate the hay may be able to cure properly and baling managed to control leaf loss without the dangers of getting rain on the hay.
Here is our management guide for controlling blister beetles in hay.
here is an old report on the use and management of swathers for what I suspect is a similar climate in California.