During the last decade, colonies of honeybee have already been ruined and scientists believe that it could be due to the mutually beneficial relationship enjoyed by a parasitic mite called Varroa destructor and the virus that it transmits.
The Varroa destructor bears the deformed wing virus (DWV), which parasite and its own pathogenic passenger have now been implicated within the incredible deficits of honeybee colonies.
Prior reports have discovered that termites as well as their offspring feast upon the body-like essential liquid (or haemolymph) of premature honeybees called pupae. This can help spread herpes that suppresses the immune system of honeybees by tampering using the signaling of the protein named NF-κB, and stress makes things worse. Nevertheless, the mechanism underlying this mite-virus association and the evolutionary implications remain largely obscure.
To determine if there exists a mutualism between the virus and the mite vector, a team brought by Francesco Nazzi University of Udine and Francesco Pennacchio of the University of Naples examined whether or not virus- induced reduction helps mite feeding.
To respond to parasite intruders and prevent them from continuing to feed, bugs encased them in a capsule coated in the pigment melanin. Therefore the group inserted a 0.08-mm bit of nylon thread within the bodies of virus-infected Apis mellifera larvae. In the following day, they removed the implants and measured the degree of the thread’s melanization and encapsulation using a light microscope.
The researchers discovered that encapsulation melanization, and also the degrees of gene expression of associated genes were adversely related to the virus levels within the larvae: Bees with higher virus loads suffered reduced immunity. Meanwhile, virus levels were positively correlated with mite reproduction on honeybee pupae. This jump in the numbers of viral genome copies and mite offspring suggests that a viral infection enhances the reproductive success of the parasitic mites.
The symbiosis between DWV and Varroa destructor perpetuates a mutual cycle – one which comes with an undesirable effect on health. This mite-virus link will be the key to understand at least one or more of the elements adding to the fall of colonies.