Diseases of Honey Bees and Their Control
Honey bees are susceptible
to several diseases caused by viruses, bacteria, protozoans and mites. These
diseases can result in anything from the death of individual bees to the
collapse of entire colonies. The spread of diseases between colonies is often
facilitated through manipulations in the apiary, as well as by robber bees,
swarms, and drifting bees. A brief description of honey bee diseases and their
control methods are given bellow-
Brood
Diseases
1.American
Foul Brood:
Causative organism: Paenibacillus larvae
(bacteria)
Symptoms: Affects the
late larval or early pupal stage. The cappings of affected cells become sunken
and punctured. Dead brood turns from off-white to dark brown and becomes sticky
and ropy, with a foul smell. Worker brood is primarily affected.
Control Measures: Treat with Terramycin at
0.25–0.4g mixed in 5 liters of sugar syrup.
2. European Foul Brood:
Causative
organism: Melissococcus pluton (bacteria)
Symptoms:
Affects unsealed larvae, causing coiled and collapsed bodies. Dead brood is
yellowish-white to grey or brown. The disease produces a sour smell, and the
affected brood is soft and granular in consistency. It affects workers, drones,
and queens.
Control:
Treat with Terramycin at 0.2g mixed in 500ml of concentrated sugar syrup.
3. Sac Brood / Thai Sac
Brood:
Causative
organism: Virus (Sac brood in Apis mellifera and Thai sac brood in Apis cerana)
Symptoms:
Affects older larvae, causing them to become sac-like with watery content. The
dead brood turns straw-colored and darkens from the head. No strong odor is
present.
Control
Measures: Currently, no effective cure exists.
Adult
Diseases
1. Nosema Disease:
Causative
organism: Nosema apis (protozoan)
Symptoms:
Infected bees become sluggish and gather in front of the hive. They exhibit
distended abdomens and dysentery.
Control
Measures: Feed fumagillin at 200mg in sugar syrup or administer Dependel-M
at 0.5g per liter of syrup to the colony, with two weekly feedings.
2. Acarine Disease:
Causative
organism: Acarapis woodi (endoparasitic mite)
Symptoms:
Bees appear as crawlers in front of the hive, unable to fly. They often show
disjointed wings in a typical 'K' wing condition.
Control:
Fumigate using Folbex strips or apply formic acid (85%) at 10ml per colony,
replenishing every 24 hours for 21 days.
