Perhaps a blister beetle, Meloe sp.. Their adult-like larvae crawl up into flowers, where they wait for a bee, then attach, return to the bee's nest, drop off, moult to a more typical "grub" larva, feed, and mature. I think these are native species, adapted to some native bee. Perhaps a Bombus expert will know. Some attach to honey bees. We've found them in our external mite detection surveys, but I've never seen one as big as 4 mm. I'd be interested to hear of what you find. Kerry Clark, Apiculture Specialist B.C. Ministry of Agriculture 1201 103 Ave Dawson Creek B.C. V1G 4J2 CANADA Tel (604) 784-2225 fax (604) 784-2299 INTERNET [log in to unmask]