Enemies of Honey Bees: Insect Pests and Diseases

Diseases of Honey Bees:

Acarine Disease (Isle of Wight Disease)

• Causal Organism: Acarapis woodi
• Place of Infection: Trachea and body fluids
• Nature of Damage: Mites reside in the trachea of honey bees, piercing the tracheal walls to feed on the bees’ hemolymph. This causes difficulty in breathing and general weakness in bees.
• Infected Stage: Adult
• Management: Use of grease patties with menthol placed on top bars of the hive to allow vaporization. Introduction of resistant hybrid bees like the Buckfast bee. Cotton soaked in methyl salicylate placed under the hive in a perforated lid. Destruction of infected colonies to prevent further spread.

Amoebic Disease

• Causal Organism: Malphigian gamoeba mellifera
• Place of Infection: Malpighian tubules
• Nature of Damage: The disease causes dysentery. The amoeba cysts are excreted in the feces of infected bees, contaminating the colony.
• Infected Stage: Adult
• Management: Sterilization of brood boxes and frames using glacial acetic acid or 40% formalin.

Nosema Disease

• Causal Organism: Nosema apis
• Place of Infection: Stomach
• Nature of Damage: The organism invades the intestinal tracts of adult bees, causing nosemosis and dysentery, which weakens and often kills the bees.
• Infected Stage: Adult
• Management: Increase ventilation in the hive. Treat with antibiotics. Remove honey and feed the bees with sugar water. Sterilize brood boxes and frames with glacial acetic acid or formalin.

American Foul Brood

• Causal Organism: Paenibacillus larvae
• Place of Infection: Gut
• Nature of Damage: Infected larvae die after their cells are sealed, turning dark brown and decomposing into a sticky mass that emits a foul odor.
• Infected Stage: Larvae
• Management: Complete destruction (burning) of the infected hive.
  • Use of antibiotics such as oxytetracycline hydrochloride and tylosin tartrate. Dusting combs with sulphathiazole powder. Dipping hive parts in hot paraffin wax or a 3% sodium hypochlorite solution (bleach).

European Foul Brood

• Causal Organism: Melissococcus plutonius (Bacillus pluton)
• Place of Infection: Mid-gut
• Nature of Damage: Diseased larvae turn yellow, then brown, and their tracheal system becomes visible. The larvae die in a coiled shape, causing a foul smell. Cells are poorly capped and mixed with healthy cells.
• Infected Stage: Larvae
• Management: Treatment with oxytetracycline hydrochloride. Use of the “Shook Swarm” technique, where diseased bees are shaken into a new hive to help control the disease.

Chalk Brood

• Causal Organism: Ascosphaera apis
• Place of Infection: Gut
• Nature of Damage: The fungus attacks larvae, consuming their body and causing them to appear white and chalky, which leads to their death.
• Infected Stage: Larvae
• Management: Common in wet springs, hence, transferring healthy bees into new hives can help. Increase ventilation in the hive to prevent the fungus’ growth.

Stone Brood

• Causal Organism: Aspergillus fumigatus, A. flavus, A. niger
• Place of Infection: Alimentary canal
• Nature of Damage: Larvae turn black and harden, making them difficult to crush. Fungus erupts from the larvae’s integument and forms a false skin, covering the larvae with powdery fungal spores.
• Infected Stage: Larvae and Adults
• Management: Sterilization of the hive with formaldehyde fumes to prevent the spread of fungal spores.

Important Pests of Honey Bees

Death’s Hawk Moth

• Scientific Name: Acherontia styx
• Nature of Damage: This moth enters beehives at night and feeds on honey. It can be quite destructive in terms of honey consumption, especially if there is a large infestation.
• Management: Strong bee colonies can expel the moths from the hive. Regular monitoring and closing of hive entrances at night can help reduce infestations.

Greater Wax Moth

• Scientific Name: Galleria mellonella
• Nature of Damage: The caterpillars of this moth burrow through combs, particularly around the midrib, during times of stress (such as when the hive is weak or poorly managed). They feed on the wax and can cause significant damage.
• Management: The moths don’t directly attack the bees but feed on the wax and combs. Use of para dichlorobenzene to treat the hive or stored combs. Prevent infestation by sealing gaps in the hive and ensuring that moths cannot enter. Use traps to lure the moths away from the hive area. Freezing the wax combs for 24 hours can kill moth larvae and eggs. Spraying stored combs with the Bacillus thuringiensis aizawai variety (Bt) to control the larvae.

Lesser Wax Moth

• Scientific Name: Achroia grisella
• Nature of Damage: Similar to the greater wax moth, the caterpillars burrow through combs near the midrib, causing damage to the wax.
• Management: Freezing beeswax combs, especially those not filled with honey, helps reduce moth infestations. Fumigation with para dichlorobenzene when combs are empty. For combs filled with honey, fumigation with CO2 can be used to control the moths.

Predatory Wasps

• Scientific Names: Vespa orientalis, Vespa magnifera
• Nature of Damage: Wasps prey on honey bees by attacking and killing them, often macerating the bees before feeding them to their larvae. This weakens and eventually destroys the colony.
• Management: Destruction of wasp nests by burning or applying insecticides. Traps can be used to catch wasps before they attack the hive. Secure the apiary and hive entrances to prevent wasps from gaining access.

Ants

• Scientific Name: Dorylus labiatus
• Nature of Damage: Ants take away honey and brood, gradually weakening and even destroying the bee colony. They can overwhelm the hive, especially during periods of stress.
• Management: Destruction of ant nests near the apiary by fumigation or using insecticides. Treat the legs of the hives with repellent to deter ants from approaching.

African Small Hive Beetle

• Scientific Name: Aethina tumida
• Nature of Damage: The small hive beetle lives inside beehives, where its larvae slime the comb, leading to the colony’s collapse. The beetle larvae feed on honey and brood and drive the bees out of the hive.
• Management: Use of para dichlorobenzene to control beetle larvae. Apply benzene in the corrugations of cardboard placed in the hive to trap larvae. Use of oil-based bottom board traps to catch beetles as they try to escape.