The Honey Bee Solution to Varroa – a practical guide for beekeepers by Steve Riley. A review by Adrian Quiney

Our local overwintering expert Adrian Quiney asks the question: Can selecting for varroa resistance be made easier?

The book begins with a bold foreword

“This is the first book that provides a practical long-term treatment free solution to the

varroa problem. The methods are simple, easy to follow and adaptable to each

beekeeper or associations’ situation and it works with any race of honeybee, kept in any

hive, in any type of environment.”

Emeritus Professor Stephen Martin F.E.S.

Reading that statement in Wisconsin, USA left me wondering if Professor Martin was

being a bit too loosey-goosey with the term “any".

However, new ideas and approaches are interesting. I thoroughly enjoyed the book

which I bought after seeing Steve Riley on the National Honey Show YouTube Channel

from England. There are parts of the UK where beekeepers are keeping bees alive with

conventional methods and no chemical treatments. The author discusses how he and

some of his fellow beekeeping association members went forward and found a path to

that goal over 6 years.

What I want to know is whether the method transfers to my part of the US, the Midwest. The book challenges some widely held concepts, with anecdotes and data local to the UK. How far can the methods travel? I am interested to know. I already see some commonalities between parts of his methods and those I practice myself.

Deformed wing virus, VSH and cold winters

In summarizing the way in which Deformed Wing Virus damages our bees Riley makes

a distinction. Quoting work by Martin and Gringrod (2020) he says “The key impact of

Varroa transmitted DWV is on the bees’ longevity. Sealed brood that are infected with

DWV by feeding varroa have their lifespan reduced by about two thirds. If varroa

feeding occurs only on the adult bee, there is a slight reduction in longevity.” This

corresponds with what I, and many other midwestern beekeepers, have seen regarding

Varroa mediated DWV hives’ demise. Most of our winter bees need to live 5-6 months

to carry colonies through the winter. When we see hives dying before Christmas it

points to DWV wiping them out a third of the way through their expected lives.

An excerpt from Riley's work charting the mite growth of a resistant colony.

Riley then goes onto explain that in Varroa resistant colonies bees limit the growth in

varroa, and thus the virulence of the viruses, by detecting and removing mite infested

varroa brood by identifying infected varroa by uncapping worker brood, removing

parasitized worker brood, and then recapping unparasitized worker brood. This should

sound familiar because here in the US we have had access to bees that do this for

many years – Varroa Sensitive Hygienic Bees (VSH bees) which were identified by Dr

John Harbo after his Collaboration with Dr Marla Spivak as they were looking at

hygienic traits.

The author explains how the participating beekeepers in his organization identified

colonies that were uncapping and chewing out parasitized larva by using the debris off

the trays they inserted under screened bottom boards. This differs from how the trait is

identified over here in the US where the Harbo Assay has been the standard for

detecting VSH. In this assay, the beekeeper uncaps purple eyed or older worker pupa

and looks for an absence of reproducing mites and the presence of non-reproducing

mites. The members of Riley’s group contemplated using that method, but elected not

to because they didn’t think they could convince beekeepers to do it.

An example of uncapping behavior seen at Lloyd St Bees

It is worth pointing out that the author takes pains to explain that it’s the “chewing out” of parasitized larva that is key, as it’s possible to see uncapping and recapping traits in bee stocks that don’t remove varroa infested larva.

He posits that in resistant colonies there are higher proportions of non-reproductive mites, and lower levels of viruses; Further, he says that resistant bees across the world are more tolerant of the viruses – that is they are less likely to die of the viruses.

Quite succinctly, he summarized that in the 14x12 inch British hives, hygienically

resistant colonies could be identified by mite counts taken from an open mesh floor (Screened Bottom Board in the US) of 5 a day or less over a year, and parts of the

exoskeleton of chewed out pupa. There was variability amongst the practitioners of this

method. Some monitored daily, others weekly, and some monthly. He held that

monthly was the minimum needed to identify resistance using this method.

"When we see hives dying before Christmas it points to DWV wiping them out a third of the way through their expected lives"

Heritability of the the VSH trait and the role our drones play

As I read the book, much of what he was saying was familiar. I and many others have

pointed out that here (in the US) continued reliance on chemicals breeds resilient mites

and those resilient mites need ever stronger and more frequent applications of miticides

to kill them. I didn’t see him mention how this affects the evolution of the viruses, that’s

a complicated story.

What he did describe was two points/concepts that were novel to me – the heritability of

the trait, and the role of drones in resistance.

An example from Riley on how his organization manages to spread their genetics.

He reports that VSH behavior was quite heritable, and that a half dozen beekeepers in

his club, each managing about 6 or so hives, were able to select for VSH behavior and

forgo Mite treatments. This was fascinating and refreshing to read. I have read

elsewhere and believed that hygienic behavior wasn’t that heritable and would be

washed away in subsequent generations. This gives me hope that the trait is more

persistent than we thought!

Local vs global

The environment of the UK is significantly different from the US, as is the bee-scape.

They don’t have the specter of the annual swapping of resistant mites at Almond

Pollination and the subsequent downstream dispersal of the chemical dependent bees

vectoring resistant mites who are carrying novel viruses like we see here in the US.

Perhaps a lower level of VSH has a higher impact over there?

Adrian showing off his nucs during a typical cold Wisconsin winter

He describes a scenario in which the drones, being the more attractive host, take the bigger mite hit whilst their brood is present, which allow more uninfected worker brood to be raised. Then, when drone rearing is stopped, there is a “pivot “as the mites leave the drones and enter worker brood enmasse as their numbers peak. This results in multiple foundress mites per cell, and a larger mite drop detectable on the screened bottom board as the bees uncap the infected brood then chew it out. Mel Disselkoen

also describes a similar mite demise when the first worker cells become invaded by multiple mites after a new queen starts laying in his colonies. As I recall it, he says that the multiple foundress mothers either kill or wound the worker pupa so badly that the

signal to remove the brood is enhanced. Interestingly, to me at least, Riley doesn’t

report that happening when the new queen of his artificial swarm starts laying; Could a

similar mass invasion could be happening at this brood break in addition to those he

reports at the drone pivot and the winter brood break in January?

Two thumbs up

This book has me contemplating the use of screened bottom boards. Whilst I am

convinced that the gold standard in VSH assessment is the Harbo Assay, I don’t enjoy

performing it, and it can’t be performed in the winter. I’d like to know what can be

inferred from mite drops and whether I can perform similar assessments and know,

before opening colonies in the spring, who is the most hygienic and which colonies are

doing the best against our age-old foe – Varroa.

I give this book a thumbs up.

Adrian Quiney, author of "The Cavity Compromise", is a sideline beekeeper and an RN who lives in Hudson, Wisconsin. He overwinters 60-80 colonies in the area around Hudson WI – a Wisconsin border town about 30 miles east of Minneapolis, MN. His area of interest is Biotechnical Beekeeping. This is a collective term for methods that exploit the weaknesses of the mite to control it without the use of chemical mite treatments. Save for an abandoned 3 week foray into sugar dusting about 10 years ago Adrian has never used chemical mite treatments. The conventional wisdom is that Biotechnical Beekeeping alone cannot keep one’s bees alive. Combining brood breaks, conventional drone brood removal, Dutch/German drone brood removal, varroa resistant stock, and the use of stacked five-over-five nuc boxes has enabled Adrian to defy conventional wisdom. He credits Mel Disselkoen of Michigan for teaching him the value of broodbreaks, and Mike Palmer of Vermont for introducing him to the value of nucs. Adrian has been giving talks about his methods and professing the value of nucs since 2012. That makes him a ten-yeared nuc professor…