How does the mite Varroa destructor kill the honeybee Apis mellifera? Alteration of cuticular hydrcarbons and water loss in infested honeybees

Pathogenesis of varroosis at the level of the honey bee (Apis mellifera) colony

“…The reduction of fresh body weight in our October-bees is therefore more likely due to an impairment of brood care in heavily infested colonies (Aronstein et al, 2012), or to the direct effects of hemolymph consumption by the mites. Nevertheless, our data support the hypothesis of Annoscia et al (2012) of a failure of the capacity to regulate body water content as an ultimate cause of death in infested bees (and colonies), which these authors link to a modification of cuticular hydrocarbon profiles. Given that thermal homeostasis of the winter cluster is likely to become problematic with numbers of individuals dropping below a certain threshold (Nicolson, 2009), it also seems possible that increased water content in the remaining bees is due to a shift in the balance between the production of metabolic water through muscle contractions for heating, and its elimination through evaporation.…”

“…Bowen-Walker and Gunn (2001) as well as Annoscia et al (2012) have shown that a substantial part of the weight loss associated with Varroa infestation in developing bees is due to an increase in water loss during development. It is therefore tempting to ascribe the reduced weight of workers in our study to water loss as well.…”

Transcriptional responses in eastern honeybees (Apis cerana) infected with mites, Varroa destructor

“…Importantly, the mite also serves as a vector and inducer of several highly pathogenic honeybee viruses, causing severe damage to bee colonies and often leading to colony death (Annoscia et al, 2012). Numerous honeybee viruses are associated with Varroa mite infestation, most notoriously colony collapse disorder (Highfield et al, 2009;Cornman et al, 2012) and deformed wing virus (Prisco et al, 2012).…”

“…destructor switched from its native host from Apis cerana to Apis mellifera 4 decades ago, later spreading to nearly all parts of the world (Sammataro et al, 2000) and becoming the greatest threat to A. mellifera health worldwide. The need for regular mite control treatments (typically chemical acaricides) to control the parasite population in western honeybee apiculture efforts (Annoscia et al, 2012) resulted in the rapid evolution of mite resistance against these chemicals, decreasing their efficiency (Damiani et al, 2009;Kanga et al, 2010). These control treatments often contaminate apicultural products (honey, pollen) with acaricide residues (Karazafiris et al, 2008).…”

High-throughput sequencing identification of genes involved with Varroa destructor resistance in the eastern honeybee, Apis cerana

“…V. destructor is also a vector and inducer of several highly pathogenic honeybee viruses that severely damage bee colonies, often leading to colony death (Annoscia et al, 2012). V. destructor spread from its native host Apis cerana to A. mellifera four decades ago and later spread to nearly every part of the world.…”