---------------------------- Forwarded with Changes --------------------------- From: Max Watkins at GBCBC001 Date: 1/19/97 3:40PM To: [log in to unmask] at INTERNET1 To: [log in to unmask] at INTERNET1 Subject: Re[2]: eradication of Varroa ------------------------------------------------------------------------------- Apologies if you get this twice - I got a system error notification when I first sent it. Max ______________________________ Forward Header __________________________________ Subject: Re[2]: eradication of Varroa Author: Max Watkins at GBCBC001 Date: 1/19/97 3:40 PM James, I agree entirely. Tropilaelaps has been know as a pest in Asia for such a long time - many reknown bee experts have documented the biology and control, notably Dr Woyke of Poland. However, I do have one additional comment on the resistance issue touched on by Dr Rodriguez: In areas where mite resistance to acaricides is an issue (and remember this is still restricted geographically - we are monitoring extensively) I don't see an alternative to Integrated Pest Management. Widespread selection of varroa-tolerant Apis mellifera is still in its infancy and is not yet applicable as an effective control measure. For now, where natural infestation and reinfestation levels are high, beekeepers will need to use some form of chemical treatment, be it synthetic acaricides, essential oils or organic acids, perhaps in addition to biomechanical means, to control Varroa. Where there is no indication of acaricide resistance - ie most of the world at present - lone chemical treatments can still be used to control Varroa, providing treatment periods are short and the acaricide has a high efficacy. Where a professionally produced and commercialised product is used, the label directions should be respected - these instructions have been developed through thorough testing of the product in various conditions. Even so, it is advisable to employ two [or more] different modes of Varroa control to prevent or at least postpone the evolution of resistance. eg drone & brood management + an acaricide. This will help prolong the lifespan of the arsenal which is needed to control this pest. Noone wants to lose a useful tool; as an industry we need to eliminate the hap-hazard mis-use of hive treatments in favour of a sensible integrated approach using legal, tried and tested methods for the benefit of all our bees. Max Dr Max Watkins ______________________________ Reply Separator _________________________________ Subject: Re: eradication of Varroa Author: [log in to unmask] at INTERNET1 Date: 1/17/97 5:42 PM Dr. Pedro Rodriguez wrote: >As the rest of the world will soon discover, there is another mite in India which has now >claimed Apis mellifera (Italian race) as their choice meal. Parasitism of A. mellifera by Tropilaelaps is very interesting and important, but it's hardly a new phenomenen in India or elsewhere. >The breeding rate of mites is so short and numerous that they really >pose an enormous challenge to scientists to overcome. Well perhaps ... but surely the obvious fact about V. jacobsoni is that its reproductive rate is extremely low in comparison with most other mite parasites and pests . This is actually an enormous point in favour of control. >Hence, the most plausible avenues of conquest of these mites is through interruption of >their life cycles with aims at erradication. Surely this is an enormous non-sequitur. Yes it is logical to interupt the mites life cycle - any method of control that doesn't do this isn't a method of control at all, after all; but it does not follow that because the mites are a big problem and because they can breed we must totally eradicate them to be able control them. Moreover, even if eradication seems an attractive idea, in reality it just isn't feasable since any eradication scheme would have to reach every single mite in every single colony to be a success. I'm sure that this point has been made enough times here before. >Chemically, we already know that it can not be achieved because of the mites ability to mutate and >develop resistance to chemicals (the fluvalinate story). The solution >lies in the utilization of physiological, anatomical and biological >characteristics of mites. It is a problem that mites can develop resistance to chemical treatments used to control them. But rather than throwing our hands up in despair, it is worth remembering that as beekeepers we can prolong the useful life of the chemical treatments that we are using by strictly adhering to the label directions so that we avoid exposing mite populations to sub-lethal doses of the active incredient as it is this which is the factor most likely to cause the development of resistance. I do agree that the long term solution will probably not be based on chemical treatments, and this is one reason why management methods (such as drone trapping) are significant. Finally, although the term chemical treatments tends to be associated with synthetic pyrethroids etc., the 'alternative treatments' sometimes used by beekeepers such as essential oils, formic acid and mineral oils(!) are chemicals too. Their modes of action may be different, but I am aware of no scientific reason that why the same issue of development of mite resistance does not apply equally to these. Perhaps those better informed than me in this field might wish to to comment. Anyway, I should say that I am quite looking forward to receiving details of Dr. Pedro Rodriguez's methods and results to consider. James Morton