Re: Phytoseilius persimillus

From: Paul Christian <paul at rareplants.co.uk> on 1999.02.08 at 23:39:37(3019) Don, all, I tend to lurk in the group but a favourite little animal got me typing. I don't know if Phytoseilius has a common name, does it need one ? If it is the beastie that I am thinking of it is a very effective predator of red spider mites. It was said that it cannot deal with a heavy infestation, this is not totally true, in my experience. Yes they of course are more quickly seen to work against low infestations and low mite densities but you need to remember that it is not a spray but a predator. There are lots of factors in its effectiveness. It eats the mites [anyone opens up a thread on how it sucks them not eats outbreed the predator, at cooler temperatures. However at higher temps ( I think ? circa 75F) this ceases to be true and then you have a marvellous situation when you have "limitless" food for the predator to eat, and predator outbreeds the prey species - that is when they can mop up pretty quickly. +More Of course they eventually reach as sort of stability but do not, as has been suggested, die when they eat up all the mites, they just die back. Thgis is ecology at work, poor predator that eats ALL the prey and then starves to death. Our Winter temps will kill them over here, but they persist in our glasshouses at 45F, or enough of thenm do to over-winter and re-establish in the spring. So bearing in mind its temp. requirements it can be a VERY effective control. Final caveats 1/ the predator is more susceptible to most sprays than the prey species. 2/ they apparently do not control well on one or two species, Passiflora is reputed to be one of these. Also a kite, it appears to me that they might control Brevipalpus (two spotted spider mite) a serious pest of Pleione and several other ornamental spp. This is based on using them here over about three years or so, well four just starting and the little devils are a delight to see zipping around the leaves in the summer, they are large enough to just be visible with the naked eye, especially the close-magnifying vision that seems to be one of the few benefits of middle age. Hope this helps ------------------------ Paul Christian BSc PhD P.O.Box 468, WREXHAM, LL13 9XR, U.K. Tel 01978 -366399 Fax 01978 266466 email paul@rareplants.co.uk website "http://rareplants.co.uk"

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