>I'm very curious as to whether it is the same signal that Apis cerana drone pupa give off to signal workers to close their capping holes and entomb them.

My understanding is that Mondet et al have a pretty good bead on the chemical cocktail that is emitted by varroa-parasitized brood (see attached).

When asking Dr. Wagoner how UBeeO compares, she replied as follows (with permission to quote):

'My understanding of Fanny’s work is that she has identified several ketones and acetates. These differ from the UBeeO compounds in that they contain oxygen (UBeeO compounds are strictly hydrocarbons) and they are associated with Varroa Parasitization specifically (hence her term VPS). In contrast, the UBeeOs are found on all healthy and unhealthy brood, but are elevated in unhealthy individuals. We have shown elevated UBeeOs in both Varroa-infested individuals and non-infested but virus-infected individuals. Given what we see regarding the disease loads of UBeeO high colonies (high UBeeO colonies have fewer mites, lower virus loads, lower Nosema loads, and less chalk brood) we conclude that UBeeO is more a general stress signal. This is supported by a finding that ant pupae targeted for unpacking (which is comparable to bee hygiene) exhibit elevated levels of one of our UBeeO compounds - evolutionarily this system may go back quite a ways. In my view this is beneficial in a practical sense, because it allows beekeepers to select for bees that are generally good at identifying unhealthy brood. One of the neat things we are starting to see is that there are different thresholds of UBeeO response required to control different diseases. For example, to achieve mite resistance colonies typically need to respond to UBeeO in the 60-100% range, while Chalkbrood resistance requires responses of only 20% or greater (indicating that Varroa parasitization is more subtle than chalkbrood infection, supported by findings from FKB selection).'

In considering the mechanisms of resistance in A. cerana, recent work by Martin et al suggests that the primary mechanism there is likely mite infertility, with a big caveat that:

'Here, the main areas of Varroa-A. cerana research have been presented, and gaps in the research have been highlighted and discussed. Ultimately, what has become clear is that our assumptions about the ability of A. cerana to perform the resistance traits grooming and brood removal are largely based on only a small number of decade old studies, often using small sample sizes. This is problematic because there is considerable natural variation in the displaying of resistance traits between colonies. Some variation exists naturally within and between populations, but it is amplified by many other factors including the seasons, environmental conditions, mite infestation levels and the methodology used.'

https://link.springer.com/article/10.1007/s13592-022-00977-8

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