From Dr. Mussen's news letter.
Experiments conducted on the fungicides alone and in many cases the IGRs alone do not appear to elicit the damage that is seen when they are combined, perhaps including a newer adjuvant. This season the losses were of such magnitude (an unof-ficially estimated 80,000 colonies) that representatives of EPA visited to observe the damage. Below are images from Dr. Gordon Wardell of Para-mount Farming, of layers of dead bees on the ground, newly emerged, wingless bees pulled from the combs by other bees, and bees that failed in their attempts to emerge as adults.
It seems that a combination of exposures of colonies to truly bee-toxic insecticides, followed by delayed effects of exposure to fungicide/IGR mixes during bloom, really set the bees way behind. The problem proved so severe that a number of beekeepers stated that they were never returning to California for almond pollin-ation. That is not a good thing, since we really don’t have too many colonies coming to almonds as it is