Bee Pests, Predators, Diseases and Their Management
Pest and disease questions ask for identification, damage signs and integrated management rather than blanket medication.
Pests and predators
Wax moth larvae tunnel through combs and leave webbing; keep combs dry and well lit. Varroa destructor and Tropilaelaps clareae are mites that deform brood and adults. Ants, termites, wasps, bee-eater birds, lizards and bears are common apiary predators.
Diseases
American foulbrood (Paenibacillus larvae): sunken, dark, ropy cappings and a foul smell; the ropy test is a field sign. European foulbrood (Melissococcus plutonius): twisted, yellow-brown larvae that are not ropy. Nosema causes dysentery and poor buildup. Sacbrood and Thai sacbrood virus (serious in A. cerana) kill larvae. Chalkbrood and acarine disease also occur.
Management
Use strong colonies, replace old combs, maintain sanitation, screen bottom boards and requeen. Approved organic acids and thymol are used against mites; infected combs are burned. Antibiotics are not a cure for viruses and leave residues.
Worked example
A comb has sunken cappings, a dark brown larva that stretches into a rope, and a foul smell. Reasoning: the ropy test plus foul smell and sunken cappings point to American foulbrood, not European foulbrood, which gives twisted but non-ropy larvae. Burn the comb, clean the hive and requeen.
Traps
Do not treat viral diseases with antibiotics. Do not mistake wax moth webbing for AFB. Do not ignore Thai sacbrood in A. cerana. Pesticide poisoning can mimic disease; check for dead foragers at the entrance.