Viral diseases

Iflaviridae

a family of small, non-enveloped viruses within the Picornavirales order

egypt bee virus

initial name for DWV

Deformed wing virus

causes the overt symptom of misshapen and crippled wings of heavily infected worker bees, often associated with Varroa destructor

DWV type A

the original virus that has been studied as the generic DWV

DWV type B

corresponds to VDV-1 and is similarly identical to DWV-A

DWV type C

a recently recognized variant recombinant of DWV-A and B

spring to autumn

seasonal variation of DWV

epithelial cells of the digestive tract and basal regions of antennal epithelium

accumulation sites of DWV

sacbrood virus

the first virus described in A. mellifera

hygienic behavior

primary means of SBV transmission within a colony

sacbrood disease

infected larvae are not able to shed their leathery endocuticle forming a sac-like appearance. brood fails to pupate and usually die during the last larval stage, stretched on their backs with heads lifted up toward the cell opening

slow bee paralysis virus

mainly a disease of adult honey bees where paralysis of the anterior two pairs of legs.

Dicistroviridae

family of small, non-enveloped RNA viruses with spherical particles

black queen cell virus

infected queen pupae had turned dark brown to black within their cells. named due to darkened areas of the walls of the queen cells containing infected pupae

black queen cell virus

: Clinical signs consist of a pale-yellow appearance and the presence of a sac-like sink, resulting in the death of queen larvae and pupae in their cells.

acute bee paralysis virus

When the virus affects adults, it causes paralysis and other obvious symptoms, including trembling, inability to fly, and the gradual darkening and loss of hair from the thorax and abdomen. associated with colony depopulation and overwintering collapse

israeli acute paralysis virus

Symptoms in naturally infected bees include shivering wings followed by progressive paralysis, which are typical signs of nerve-function impairment. Other symptoms include darkening of the abdomen tips and thorax, constant movement, reduced flying or eating, black abdomen and thorax, hairless thoraxes, and shivering wings.

chronic bee paralysis type 1

Symptoms include an abnormal trembling motion of the wings and bodies of paralyzed bees. These bees are unable to fly, frequently huddle together on top of the bee cluster or in front of the colony entrance, and crawl in front of the hive on the ground or vegetation.

chronic bee paralysis type 2

Bees can fly but become almost hairless, appearing dark or almost black (seemingly smaller than healthy bees). They have a relatively broader abdomen and are shiny, appearing greasy in bright light. Within a few days, they become flightless, tremble, and die.

Apis mellifera filamentous virus

infection leads to lysis of fat body resulting in a milky-white appearance of worker hemolymph. acutely infected bees are often found crawling at the hive entrance.

trophallactic activities
hygienic behavior
grooming
larval cannibalism

frequen horizontal transmission of viruses

Varroa destructor

played a critical role in changing the virus ecology

RNA interference

a post-transcriptional, sequence specific gene regulation mechanism that plays a vital part in insect antiviral immunity

cell culture and infectious-virus molecular clones

considered the gold standard for isolation and viral diagnosis

electron microscopy

most important technique for diagnosis and virus discovery. offers the possibility to classify viruses based on their capsid morphology

symptoms

one of the principal methods to diagnose infections in the apiary greatly relying on beekeeper expertise