www.vita-europe.com

VARROA MITE

The Varroa mite, Varroa destructor, is the most serious threat to the western honeybee, Apis mellifera. Varroa is a parasite that feeds on the bee and spreads viruses. Untreated, colonies die in a few years.

Monitoring mite fall with varroa floorsgives early warning of dangerous varroainfestation. In Europe, calculate the mitepopulation from natural mite fall:multiply daily mite drop by 250–500when no brood or 20–40 when broodis present. (Martin, 1998).

Female varroa lay their eggs in brood cells,especially drone brood cells. They feed o�developing bees and impair normal growth.

Varroa spread viruses and amplify their e�ects.Deformed Wing Virus (DWV) is a typical signof Varroa infestation. Other viruses, oncethought insignificant, are also killing bees.

Varroa Impact

Since the early 1900s varroa has spread throughout the world. By 2016, Australia, one of very few countries that appeared to be varroa-free, seemed under threat..

Varroa populations keep growing at the end of the season even as thehoneybee population declines. So treatment at the end of the honey flow and before winter preparations is essential.

Varroa mites attach themselves toflying bees and spread with robberbees, drifting bees, swarms andmigratory beekeeping. Varroa infiltrate colonies by mimicking thescents of bees. They even know when colony collapse is imminent and leave with the absconding beesto infest another colony.

Treatment, IPM and resistance

Varroa cannot be eliminated, but numbers can be controlledusing e�ective and approved treatments that are safe for bees, honey, humans and the environment. Overuse of single treatments accelerates resistance, so alternating treatments with Integrated Pest Management (IPM) is essential.

J F M A M J J A S O N D

40,000

30,000

20,000

10,000

0

10,000

5,000

0

6 Mitesper

100 Bees

35 Mitesper

100 Bees

BEES MITES

Apiary spread

1904

le

aves

Java

as

Varro

a

ja

cobs

oni

1960

s d

iscov

ered

in U

SSR

1970

s d

iscov

ered

in E

urop

e

1980

s fi

rst g

ener

atio

n

tr

eatm

ents

eg

Apist

an

1987

d

iscov

ered

in U

SA

1992

d

iscov

ered

in B

ritai

n

1996

ro

le o

f viru

ses

in V

arro

a

im

pact

real

ised

1990

s s

econ

d ge

nera

tion

trea

tmen

ts e

g Ap

igua

rd

1990

s P

aras

itic

Mite

Syn

drom

e

term

coi

ned

2000

Va

rroa

dest

ruct

or

re

cogn

ised

as d

i�er

ent

spe

cies

to V

arro

a

ja

cobs

oni

2000

disc

over

ed in

New

Zea

land

2000s 1980s 1970s 1960s 1950s First detection

Spread of the Varroa mite, in selected counties over a series of decades

1972 Brazil

1977 Germany

1959 China

1961 India

1904 Indonesia

No reports No information

1987 USA and Canada

2007 Hawaii

2000 New Zealand

Data source: Atter Webster TC, Delaplane KS 2001, Mites of the Honey Bee

Global Spread

Tim

elin

e