ML 139313


Interview 7:27 - 29:40 Play 7:27 - More
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Mark Feldlaufer  







Honeybees; Parasitic mites  

NPR/NGS Radio Expeditions
13 Nov 1996

  • United States
    Prince George's County
  • Beltsville; USDA Bee Research Laboratory
  • 39.04112   -76.86391
  • Stereo
    Sampling Rate
  • 48kHz
    Bit Depth
  • 16-bit
    Equipment Note
  • Stereo=1; Decoded MS stereo

Bees Tour of Lab with Mark Feldlaufer
DAT #9
November 13,1996

MF = Mark Feldlaufer
AC = Alex Chadwick

5:17 ambi

6:10 MF -this is the bee research lab in Beltsville.

ambi -walking into lab

6:22 MF -I'll take you upstairs to the lab where most of the work occurs, at least the part that i am responsible for ...walking up stairs 6:53 this is one of my labs. as you can see it looks like it-has been set up like a chemistry lab, this is what they look like...MORE ... the observation colony which goes out the window of the lab...

7:31 MF -my name is Mark Feldlaufer. I am a research scientist with the Agricultural Research Service. I have been here for 14 yrs most of that time in a different lab. and currently i am working on some of the problems facing the bee industry. 7:49 -I am working on primarily 3 diff. projects. One is a bacterial disease of bees, know as foul brood caused by 1 or 2 bacteria; i am working on a pest of bees known as the wax moth -it is a pest of stored comb. What the bees normally breed in, lay their eggs in, deposit the honey in. When it is not being used it is attacked by this bee and destroyed. So it is considered a pest of bee products. ANd the 3rd and probably most important thing we are working on in this laboratory is parasitic mites of honey bees. They have received a lot of press in the last year or so. They are basically 2 parasitic mites we are looking at. One in Varroa jacobsoni, which is a large external parasite of the bee, and the other is a much smaller microscopic mite called the tracheal mite because it lives in the trachea or respiratory tubes of the bee. so currently i m looking at those three different products, and our emphasis to this day has been on control. there is a lot of biology that is necessary to be done, but for the time being the parasitic mite has become a problem, especially varroa where it has become impossible to maintain honey bee colonies w/o some kind of chemical treatment to control infestation. 9:16

9:17 AC -Well, what kinds of chemicals can you use to control these things. Do you have good agents for it?

9:24 MF -Right now there is one kind of chemical registered in the US for the control varroa, the varroa mite. This is fluvalinate which is marketed under the trade name of Apistan. And it is applied as a pesticide, impregnated strip in the hive. There is one other chemical that is registered for use with tracheal mites which is menthol. And the results with menthol have not been good. It appears that the efficacy of the compound in temperature dependent as long as the temp is warm enough, and can't give you an exact degree either in cent or faren. it seems that in colder climates when the compound is not vaporized you do not get good control. going back to the varroa mite Apistan has proved effective, but there are reports coming out of Europe, most notably Italy and France that varroa is showing some resistance with Apistan. We are currently looking at a new formulation of formic acid. Formic acid is used in other countries, Canada and other parts of Europe, to control the varroa mite, and tracheal mite. It is not registered w/EPA as we speak, but my understanding is that the paper work is there and it is being processed. One of the problems with formic acid is that it is used as an acid, 65%. Its supply from the produce is either 90 or 95%, so there is some danger in just the dilution of the 90 to 95% just to the 65%. While not as dangerous you could argue as hydrochloric acid or sulfuric acid it is still caustic and there are liability problems we have developed a gel formulation of formic acid which we feel is safer and more effective. Safer because of the obvious reason, not having to handle the liquid. More effective because we feel you can get away with a single treatment. 11:44 -In the countries that use the liquid they often have to go into the hive 3 to 5 times to get effective control. 11:52

11:53 AC -Have the Europeans kind of defeated this through chemicals -to what extent has Europe already gone through the process that we are going through now, and sort of dealt with it and come up with the right answer, eventhough i gather that the right answer really is a better bee. as you say a biologic answer. 12:18

12:19 MF -yeah. even that is 'questionable. I think the parasitic mite problem in Europe is very similar to what we are seeing here. they have used more chemicals to control the mite and yet it is still a problem. they use a combo of fluvalinate and formic acid. in this country because of the regulatory requirements only fluvalinate has been approved, and as I said formic acid is in the works. there needs to be the development of environmentally compatible acaricides, and i think that ¬

AC -what is acaracide?

13:03 MF -acaracide is just an insecticide with control of the insect, since mites are acarid, they aren't insects, they are more like spiders and ticks -in fact all ticks are mites. they aren't insects, they are acarids. so acaricide would be a compound directed specifically at a mite problem. One of the problems of chemical control is the close association btwn mite and bee. the mite develops on immature bees, inside of an individual cell that has been capped off by the adults. so just if you had an effective chemical, it would be difficult to deliver it to where it is needed.

AC -Impossible it sounds like.

13:46MF -Well, not impossible, because fluvalinate does work because the adult bees do pick it up and carry it around through the hive. But any type of chemical control is exacerbated by the potential for pesticide contaminated honey and bees wax. THe fact that above where all of this is going on is a product which is going to be used for human consumption makes it a real concern. 14:13

AC -I would think so, yeah. People are just horrified at the prospect of introducing chemicals into their food, especially food like honey -which we think of ¬

MF -A natural product in its own right.... one of the reasons it looks like formic acid will be registered is that you can find naturally existing levels of formic acid in honey. and even ¬not only in bees and the honey, but throughout the insect world. The scientific name for the family that the ants belong to is Formicidae, and it comes from the fact that they give off formic acid as a defensive secretion. 14:56 So, in a certain way formic acid could be considered a natural product, and this is where much of the emphasis on compounds for control are headed. They have more public control on being a natural product. 15:12

15:13 AC -You have a beehive here, or least a small collection [MF -an observation hive] of bees. Could you just show me how you would treat these bees in order to defeat the mites.

MF -Ah yeah -it is a little difficult in this setting because this
is made strictly for observation. If we were to go outside to a hive you find 10 of these frames lined up side by side.

AC -This is a bee hive [MF -a section] -about 3 inches deep and maybe 2 feet -maybe a foot in a half by a foot and a half and it is glassed paneled so we can look through it and see it is just full of bees and a hive.

15:57 MF -In reality, one hive body would be considered this section wj10 more of these frames, extending horizontally.

AC -So this is kind of a double section...

MF -a double section here. and in fact you can have a triple and a quadruple. most bee keepers this would be considered the brood area, and the area -the hive bodies above would be for honey. bees tend to put their immature brood down in the bottom hive section and they store honey up here...MORE ... (re. the hive set up) ...MORE

16:42 AC -but how would you get your mite treatment into these bees here, and what would happen?

16:47 MF -With the current product, fluvalinate -is supplied as a pesticide impregnated plastic strip and the bee keeper would have to open up the hive and hang these strips btwn the frames. 2 strips per hive, or hive body. Now one of the things that we are looking at which I think may -we haven't examined it yet is the use of smoke as a natural cure for the mites. In so much that all bee keeper, prior to opening up a colony, smoke their hive. It seems to have a calming effect on the hive. Anyone who has been around a bee hive knows that bee keepers keep a smoker in which they burn either burlap, pine needles, peanut shells -whatever seems to be available in the area and they puff in the front of the hive, and the sections of the hives as they open it. it is our feeling that if you could develop either an alternative smoker fuel, a smoker fuel which contains a natural compound to control the mites, or if that is not possible, use conventional smoker fuels: burlap, pine needles and peanut shells which have been impregnated with an essential oil which have been used to control mites, and use that as the smoker fuel. This would be what I would considered somewhat of a non-invasive process. And one of things in developing alternative methods, and it is something for working with bees that I never really considered which is the ease in which a method can be integrated into existing practice is very very important -for the hobbyist bee keeper which may keep one or two colonies it is not very labor intensive. But for people that keep thousands of colonies -at this mtg there was a gentleman, who I think you interview you keeps tens of thousands of colonies integrated a control method into that type of situation has to be considered. And therefore we think smoke offers a good possibility because they have to smoke their hives anyway. Jeff has just given us a strip of Apistan, fluvalinate. As you can see it is about an inch maybe a .little more in width and maybe 9 or 19 inches. And this would just be hung from the frame just like that. and this of course has to go in after nectar flow, honey flow, ...after the honey gets taken off the colony -so there are registration restrictions on the use of all of these pesticides to eliminate if at all possible to chance of pesticide contaminated honey. 20:01

AC -You were going to see if you could make the bees buzz in here ...MORE ...what is that?

20:29 MF -What that is is just a small cage where we try individual studies of new compounds. You can see it is just fashioned out of petri dishes and some hardware wire. up through the top in an inverted test tube with sugar water so the bees have something to eat.

AC -So -you are trying new compounds in here -to what?

20:50 MF -In this particular instance what we need to do is before we can determine if a compound is effective and controlling mites, we have to make sure it is not effective in killing the bees themselves. And as you know -if you look out through the window and saw the number of colonies it would be very difficult to test a large number of products if you have to use an individual colony for each one of those tests. so here in fact we have is what is known as a cage study and you gain some info from this. what goes on in a cage doesn't necessarily go on in a hive. but if something is highly toxic to bees in a cage the chances are you are going to have problems with it in a hive.

AC -so this is as big as maybe a small jar, but it is really made up of this wire, and there are maybe what -2 dozen bees in there or something like that?

21:47 MF -Yeah. 20 or 30 bees. ANd this can be adjusted. there is nothing technologically advanced.

21:58 22:15 AMBI -bees in BG

22:25 AC -So those bees in there -you are testing some product in there that you think might work, or might not ¬

MF -That is correct ¬

AC -how many of these things do you have going?

MF -that depends on the time of year. sometimes we do like using, if not a normal hive, we have several green houses where we can keep individual hive bodies and test them. and that -it more closely imitates what goes in in the hive. but during the winter if we are interested in topically applying the compound...MORE ... 23:19 the compound that you want to use to control mites doesn't adversely effect bees.

AC -how difficult is it to get a compound like that? aren't bee particularly sensitive creatures?

MF -that is correct...and somebody said at one time that it would be nice to breed a bee that was less sensitive to pesticides. That is one of the problems they have in pollination ecology -bee keepers that actually rent their hives -they keep their hives not so much for the honey that is produced but they rent them to growers and in fact i would say that more money is generated in that avenue than actual honey production. i don't know the dollar value for how much honey is produced, but depending upon whose estimates you look at honey bees are responsible for pollinating crops whose value approaches 10 billion dollars. so this is where i think the real benefit of the honey bee is. that sometimes isn't seen -24:32 it is often thought of. but getting back to your question we don't really want a bee that is less sensitive to pesticide. if the pesticide is applied, and the honey bee dies, you know you have a problem. and this all ties in with the production of honey for instance that is going to be used for human consumption. and there are people that argue that possibly there should be different regulations for honey producers than for those people that rent their colonies to growers. 25:06

AC -But this question of the sensitivity of bees to pesticides versus mites -how do you ¬

25:16 MF -Well, a large part of that is no different that the sensitivity of vertebrates or us to pesticides vs. bees. you are talking about mites and bees. many of these compounds are not very selective. it takes so much to kill a bee, and it takes a lot less to kill a mite and so you try to lay that in btwn. and i think this is true w/many of the pesticides even in agriculture out in the field. you know it takes so much to kill an animal and a lot less to kill an insect. and you try to lay in in btwn. and you know i think the reason people are interested in reducing our reliance on conventional pesticides because of their inherent danger which is something that just goes along with just controlling insects or whether it is an herbicide and controlling weeds. 26:13

26:32 AC -you have some of these mites around here?

MF -yes i do ...MORE ...happen to have some in the refrigerator.

AC -this is a little flask

MF -they are being stored in methanol where they will keep, and I think that from anyones point of view the thing that is noticeable is that this is the varroa mite and i think it is quite large when you understand it is a parasite of the honey bees. w/o having a camera here if you were to make a comparison to me it would be like making a comparison the size of a coaster or even a coffee saucer on our body -they are quite visible to the naked eye, and they actually quite large.27: 23 ...MORE ...

AC -why -bees are such fastidious creatures, they have all of these cleaning things that they go through -why don't they clean those mites off. because on a bee that mite would be enormous

MF -You must have been reading up because there are claims that ¬this mite was an original parasite of the Asian honey bee and it is not native to the honey bee that we have in this country...MORE ...and it ends up that the Asian honey bee is quite tolerant of these mites. now there are a lot of thoughts as to why it is so...MORE .... (reasons why -controversy) 29:27 Some people feel that the Asian bee is less sensitive to the mite because of hygienic behavior, but more currently in the the literature, that theory has become equivocal. 29:42

31:00 - 36:14 -ambi of room -lab -compressors, fridge hum in bg

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