Midnite Bee-Beekeeper's: Article ARTICLES Apistan use Proper Use of Apistan Apistan strips have been successfully used by beekeepers to control Varroa mites for the last nine years. Apistan is the only federally registered product for use in beehives for the control of Varroa jacobsoni. During the past six months, however, rumors have circulated throughout the industry concerning problems with the strips. We would like to provide you with the most up-to-date information on this situation. The concern is a lack of efficacy associated with the strips in limited areas of Florida, South Dakota and Pennsylvania. In some cases, the strips failed to provide the control that beekeepers have been familiar with and come to expect from Apistan. Zoecon personnel began investigating following several reports of control failures. Once the lot numbers and strip wre provided, a list was compiled to determine if a common lot number or batch was involved. Strips provided were chemically tested to determine levels of fluvalinate and inert ingredients. Batch records of each reported lot were reviewed for inconsistencies. After reviewing all the lot numbers, batch records, release rates and chemical analysis, there were no production problems with any of the strips from the reported lot numbers. There was no correlation to lot number in any of reported failures. Lot numbers reported came from production as far back as 1995 and as recently as March of 1997. During the course of the investigation, independent of Zoecon, the USDA (Weslaco,Texas) began investigations of reported failures in South Dakota. Apistan strips failed to provide satisfactory control in their studies. Further studies in certain areas of Florida had similar findings. In still other investigations, the USDA has taken strips that failed to work in Florida to parts of Texas, Mexico, and Guatemala. In case studies, the exact same strips provided control of mite populations. There does appear to be a common link between failures in South Dakota and Pennsylvania. It appears these hives have spent some time in Florida either overwintering or as pollinators shipped out of Florida. This commonality indicates possibilities there is a low -level tolerance to fluvalinate associated with these limited areas of Florida.We do not know what the level of tolerance is at this time. For the majority of beekeepers, Apistan is still and will continue to be an effective product for the control of Varroa mites. Zoecon is working intensively in conjunction with the USDA to devise alternate strategies and alternate control measures to assure Varroa-free colonies and prevent the spread of tolerant mites. In an effort to reduce the incidence of fluvalinate-tolerant mites, we urge beekeepers to only EPA-registered products and follow the label directions. The use of any unregistered product threatens a beekeeper's livelihood. For instance, pattern of illegal use of Mavrik in Italy caused a resistance problem and resulted in the ceasing of Apistan sales in that country which deprived them of an important tool. The use of any unregistered product also exposes the beekeeper to unnecessary liability. Until we know more about this situation, we urge beekeepers to monitor their hives closely for the presence of Varroa. Again, we are working to find alternatives to Apistan that can be used in rotational practices. Rotational practices will not only prolong the life of Apistan, but provide beekeepers the confidence and control they have grown to expect from Zoecon Apiary products. Wellmark International, Inc.-Greg Braithwaite