Hygienic Bees & Seasons’ Snippets.

Happy holidays everyone.

We had magical twinkling frosts here all day yesterday with the temperature only just creeping up briefly above freezing. Breath hung on the air, and truckloads of “steaming” manure lay piled in heaps on the fields below Piperhill reassuring me of a new growing season ahead, and slowly lengthening days from now on. A dazzling sun shone through clouds of condensing moisture creating an ethereal image and almost obscuring the muck spreading tractor from view as I drove home from town. Sadly, it was too dangerous to stop on the road for a photograph because the sun is so low that just driving into it is challenging at this time of the year.

The last of the beautiful Ross rounds are traveling down the A9 to Edinburgh in a shoe box as I write. They are inside a car driven by Steve, a retired Virgin Atlantic airline pilot, who is kindly delivering my last honey order before Christmas. Free honey sweetens the deal! Steve is one of my best customers and has developed a keen taste for comb honey so appreciates even the imperfect sections I’ve given him.

Tomorrow, a very famous person in Nairn will open a Christmas present and will discover a Ross round gifted by another of my best customers. Despite my misgivings about the plastic, I can see more Ross rounds being produced next season.

A text message from Ryan asks for more honey to stock his traveling fish van which sets off from Buckie every day and services both the east and west coasts. He stocked up only a week ago but sold out almost immediately. “No hurry” he messages as he has 10 days off now. The Buckie fishing boats will be in harbour over the festive season. I’ve sold out of jarred honey, sections and rounds too so need to get a couple of buckets from my store room and make some soft set honey after Christmas.

Thank You.

Thank you to all my supporters. You are amazing, and without you Beelistener would be nothing. I want to thank everyone who contributed guest blogs, made comments and offered new information. To those who subscribed for free weekly blogs and helped send Beelistener to number 31 in the top 80 beekeeping blogs, (according to Feedspot) thank you. Thank you very much for your generous donations everyone, and welcome to new readers from Myanmar, Moldova, Mongolia, Laos and Brazil. We now reach 114 countries.

Hygienic Bees.

It would be true to say that my greatest influencer this year is Steve Riley from Westerham Beekeeping Association. Steve’s work on hygienic bees and treatment free-beekeeping inspires me to learn more and do better in my own apiary : https://www.beelistener.co.uk/category/varroa-resistant-bees/

I’m a patreon of InsideThe HiveTV https://www.insidethehive.tv/site/about which is a valuable resource to me and I know that I can rely on scientist Humberto Boncristiani to do his best for the bees and their keepers by sharing sound information. As a patreon, I can email Humberto and ask questions or have a zoom chat. There are lots of other benefits but these are the important ones for me.

One of my questions prompted Humberto to review the literature on hygienic behaviour and his most recent live session with fellow scientist Kaira Wagoner reassures me and gives great hope for easier ways for beekeepers to test for hygienic traits in their bees very soon.

Alarm: Brood Cannibalisation Spreads Viruses.

I looked at several papers discussing how hygienic traits can be assessed in our colonies by killing an area of brood in 250 cells. Having killed the brood, one records how long it takes nurse bees to clean out the cells, then the percentage of cleaned cells is calculated and the levels of hygienic behaviour traits estimated from this record.

The brood may be killed by freezing using liquid nitrogen, not readily available to hobby beekeepers, or by pricking the cells with a pin which is time consuming. Dead brood give off chemical messages (semio-chemicals) from their various diferent cuticular compounds including oleic acid. These alert the bees to clean out the cells.

Recent illuminating work on hygienic behaviour in Sweden, by Oddie et al (1), shows how some nurse bees uncap brood cells in which varroa are reproducing and this interrupts the varroa breeding cycle. They cannot catch the varroa who quickly leave the opened cells but it reduces varroa levels because they cannot reproduce as quickly as normal. If the pupae are diseased they are removed, but if healthy their cells are recapped. Aren’t these chemical messages pretty smart ways of communicating?

Slight Panic.

When the paper by Evans et al (3) came out earlier this year suggesting that cannibalisation of diseased brood causes the spread of deformed wing virus, I worried that selecting for this trait might not be a good thing after all. I asked Humberto about this but now I am reassured that it is a very important thing to continue doing. However, selecting for the hygienic trait alone is not good and it must be selected for alongside other wanted traits such as gentleness, honey production or whatever your most wanted traits are.

I’ve just listened to a recording of the very recent live session with Dr Kaira Wagoner on InsideTheHiveTV. She validates the recent reseach of Evans et al on cannibalism and spread of virus which complements her own work, but she explains that this was a lab experiment and the bees were caged and not fed for a couple of hours which meant that bees removing unhealthy brood were forced into trophallaxis and food sharing so they passed on deformed wing virus during this act. In the field, honey bees usually protect the colony from disease by altruistic behaviours such as leaving the colony to die, or avoiding contact with healthy bees. In effect, these bees removing unhealthy brood are probably acting as a virus “sink” and not going on to feed other bees and spread disease. Rather, their roles and lives are probably reduced to spare the rest of the colony.

Over the past 10 years, Wagoner (2) has carried out painstaking research on brood cuticular compounds of which there are 40-50 different hydrocarbon compounds (listed in her paper). She calls the smells given off by sick brood Unhealthy Brood Odours (UBO) and has precisely replicated and synthetically manufactured them. Using a spray, containing UBOs, on an area of only 50 brood cells Wagoner has carried out UBO assays, similar to those carried out to test colonies for freeze or pin killed brood removal, and discovered that colonies with a high assay score have lower mite counts. This means that the most efficient colonies at cleaning cells had lower mite levels. She explains that UBOs are not varroa specific but probably caused by stress. Colonies of ants use UBOs to detect sick ant brood too and they do not have varroa.

UBO Spray for Beekeepers.

Watch out for a spray coming on the market soon and being available for beekeepers to test their own bees for hygienic behaviour traits. Wagoner and colleagues have formed a company called Optera to manufacture this product in the near future.

References.

(1)file:///C:/Users/ann/Documents/Research%20Articles/Reproductive_success_of_the_parasitic_mite_Varroa_.pdf

(2)https://academic.oup.com/jinsectscience/article/21/6/4/6414651?login=true

(3)https://pubmed.ncbi.nlm.nih.gov/33903723/