The Amazing Dr. Samuel Ramsey & His Talk on Tropilaelaps Mercedesae Mites at ABF2020
Today I got to see the famous Dr. Samuel Ramsey—the University of Maryland bee scientist who pioneered research that discovered that Varroa mites feed on fat bodies, not hemolymph (blood in invertebrates)—speak about his new research into an emerging threat to apis mellifera at the 2020 American Beekeeping Federation conference in Schaumberg, IL.
And—wow—his talk did not disappoint! Both informative and highly entertaining, I now completely understand why Dr. Ramsey is so popular in beekeeper circles! Jokes! Music! Drama! This scientific presentation had everything including substance.
In this post, I will attempt to recap some of the key points from Dr. Ramsey’s talk on a parasitic mite—tropilaelaps mercedesae—for those who were unable to attend the conference. This is no way diminishes his talk or replaces the recommendation to see him speak for yourself. His 8am presentation kept everyone awake, engaged, and laughing throughout. He provided a ton of information and took a ton of questions from the audience and answered each one thoroughly. If you ever get the chance, I suggest you see him speak.
Dr. Ramsey is raising funds to continue his research on this GoFundMe site. Please help fund his important research. Dr. Ramsey has also co-written a research paper with his Thai research partner Dr. Chantawannakul, available here.
A New Mite, A New Threat: Tropilaelaps Mercedesae
Tropilaelaps mercedesae (“Tropi” for short) is a parasitic mite—smaller than varroa mite—that is currently an incredible issue for apis mellifera beekeepers in Asia. Tropi is an emerging major threat to North American beekeepers because it is spreading like Varroa spread before being introduced to North America, and Dr. Ramsey suspects it will eventually move West. Dr. Ramsey has been conducting studies in Thailand (this is what his GoFundMe funds) to try and determine how Tropi operates, what Tropi feeds on, how Tropi spreads, and what methods of treatment can be used to stop Tropi. While, at the time of writing this post, Dr. Ramsey does not have all the answers to these questions yet, his continued research will hopefully result in a full understanding of how this dangerous mite works and how to combat it.
Differences between Varroa and Tropi
Tropi is smaller than Varroa mites. Tropi is also much faster. Watching the video of Tropi was honestly a little scary—they move incredibly fast for parasitic insects; the speed is visible to the human eye and disconcerting. The following video, taken by Dr. Lilia de Guzman, shows the speed of Tropi.
They are also speedy in their reproduction cycles. Varroa mites do not mate when they are on adult bees (typically 1-13 days). Tropi are not well-equipped to hold onto adult bees. Their physiology makes it easy for them to fall off flying bees. They have been observed on adult bees for a much shorter period of time than Varroa (2 hours to 2 days) and, when they fall off or descend, they are back to mating. Therefore, the Tropi mating cycles are shorter and faster.
With Varroa mites, male mites die under capped brood and only females emerge. With Tropi, both male and female mites survive the capped brood stage, are able to emerge and continue mating. This also provides a bigger gene pool for them, which provides more genetic resiliency.
Varroa exhibit a dormancy period of around 10 hours when entering brood chambers to feed. During this time, they typically hang upside down. (Dr. Ramsey does not currently know why Varroa do this and is interested in uncovering why.) Tropi, on the other hand, exhibit no dormancy and can go straight to feeding on brood.
Varroa mites are polite when feeding on brood. They typically create one wound and feed out of it. Tropi are not so polite—they create a new wound on the brood whenever they feed. The wounds, described Dr. Ramsey, can create something like scar tissue and prevent the bees from developing properly where the wounds are. He described bees developing without the use of certain legs, because the Tropi wounds had damaged them in the brood cells.
Tropi appear to use their front 2 legs as antennae, “drumming” them before undertaking activities such as feeding. Tropi (and Varroa) do not appear to feed on the developing brood’s aorta, where the most blood would be. Instead, they appear to feed to the sides of the aorta, where deposits of fat sit.
How to stop Tropilaelaps mites
Dr. Ramsey is continuing to research how Tropi spreads, given that they aren’t well-equipped to hold onto adult bees, especially bees in flight. Varroa is spread by bee-to-bee contact and robbing, but how does Tropi spread? Dr. Ramsey hypothesizes that Tropi mites may travel from hive-to-hive on foot, and will be conducting experiments with moats to see if that is true.
Dr. Ramsey is also conducting research into how to treat for these mites. Because Tropi do not hang out on adult bees for very long (as opposed to Varroa), treatments of Amitraz are ineffective. In fact, by being exposed to sub-lethal levels of the chemical, Tropi may develop resistance to it. Instead of targeting Tropi when they are on adult bees, Tropi must be combatted in the capped brood cell.
One of the studies that Dr. Ramsey described (he talked about multiple studies) in his presentation is an initiative that is still underway. Dr. Ramsey and team are testing 3 different treatments in full hives:
- Formic Pro
- Formic “Thai Style,” which is paint stirrers dipped in formic acid
- Heat treatment of 106 degrees for 160 minutes
Preliminary observations put Formic Pro at #1 with Heat Treatment a close second (heat treatment hives have Tropi returning to some hives after heat treatment). Dr. Ramsey says that this study will continue and he will likely have more information on the results in May.
Tropi are hard to count. Because they don’t stay on adult bees for long, an alcohol wash usually under-reports how many Tropi are in the hive.
There was also a very interesting connection with how Tropi survive brutal winters and rats (yes, the mammal, rats). I will wait to post more about this until Dr. Ramsey has completed more research on this and has more concrete observations.
Fund his research so that he can afford to equip western beekeepers with the knowledge to combat this rising threat.
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9 Responses
Great overview and thanks for sharing! One important point of distinction is Dr. Ramsey found that Varroa Destructor feed on Fat Bodies (not Fat) and not Hemolymph. Fat Bodies are like our liver.
Additionally there is a typo of know instead of now, in paragraph two.
Thank you J.G.! I will update the post to reflect your comments. Appreciate the comment.
What equipment was used to preform the thermal treatment?
Dr. Ramsey mentioned wired heating pads. Unfortunately, I didn’t note the brand name or if it was a beekeeper-specific product. He also mentioned that this tactic (with the wired heating pads) likely wouldn’t be efficient or convenient to commercial beekeepers.
What states have Tropi been found in to date?
Hi Robert,
Tropi have been found in 0 US states to date, as far as I am aware. Even though they are not in North America yet, the reason that Tropi should be on the radar of American Beekeepers and bee researchers is that, according to Dr. Ramsey, Tropi is spreading in a similar manner to how Varroa spread. Dr. Ramsey: “They’re not here yet but they’re spreading the same way that Varroa did in 1977, just ten years before they were found in North America.”
Tropi is native to Asia, but “has been expanding over the last 50 years” and can be currently found in regions beyond their native range, which includes Papua New Guinea and Kenya.
You mention Tropi returning to the hive after heat treatment, but since there are none In the USA and I don’t think Dr. Ramsey went to Asia for the test I think it should say Varroa.
This is Tropi. Dr. Ramsey is conducting his research in Thailand.
Thank you. I wish he would do a thermal therapy test in the USA where I live.
Comments are closed.