sentences:  Alfalfa is considered an insectary, a place where insects are reared, and has been proposed as helpful to other crops, such as cotton, if the two are interplanted, because the alfalfa harbours predatory and parasitic insects that would protect the other crop.Harvesting the alfalfa by mowing the entire crop area destroys the insect population, but this can be avoided by mowing in strips so that part of the growth remains.Like most plants, alfalfa can be attacked by various pests and pathogens.