Re: Varroa: Beauty of paper
Frankly, I found it disappointing. It reads like an encyclopedia summary of what we know, with little that's new. Especially regarding mite dispersal. They say:
[quoted material]
Understanding the Varroa Life Cycle
The life cycle is split into two distinct phases:
* The reproductive phase that takes place inside honey bee brood cells, where a foundress
mite raises her young
* The dispersal phase – often incorrectly termed the phoretic phase – in which mature female
mites travel and feed on adult bees
Highly infested weak colonies facilitate mite dispersal and disease transmission to stronger and healthier colonies.
Phoretic phase: traditionally, phoresy means that an organism (such as a mite) uses another organism (such as the honey bee) for transport, but specifically without feeding during that time. As varroa feeds on the honey bee host during this phase, we advocate for a change in terminology to the 'dispersal phase'.
Parasite-Induced Changes Enable Colony Dispersal
Varroa mites alter the hydrocarbon cuticle of their hosts and adapt their preference for different adult-host life stages based on colony infestation levels [37]. At low mite abundance, varroa preferentially parasitizes nurse bees, which frequently tend to brood and thus provide opportunities to infest an appropriately aged larval cell. Varroa distinguishes nurse bees from foragers by different chemical cuticular signatures [38]. When mite abundance increases in the colony, the chemical profile of nurses and foragers tends to overlap, promoting mite departure by dispersing onto foragers [37]. Parasitized brood develops into adult bees that spend less time nursing, mature at an accelerated rate [39], contribute less to colony productivity, and potentially promote varroa dispersal to new colonies [1,40].
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Comments
The citations refer to older papers, and upon viewing, they have little to add. Considering that the authors state themselves that "The life cycle is split into two distinct phases: * The reproductive phase [and the] * The dispersal phase" -- it is somewhat puzzling they have so little to say about dispersal other than to suggest we stop calling it phoretic.
I have never been satisfied with any explanation of how varroa spreads so rapidly in the landscape. Surely "robbing" can account for it somewhat, and the idea of "precocious foragers" fits in, but there may be specific mite behaviors that have not been elucidated. Of course, this is field work, which is expensive and time consuming. I hope someone does it, some day.
PLB
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