Amoeba
Dysentery on the landing board is not always Nosema
Monitoring for Amoebic Disease (Malpighamoeba mellificae) in Honey Bee Colonies is the UF/IFAS detection page. Gurland, Fulton, Iredale, Vu, and St. Amant. The amoeba lives in the Malpighian tubules, the organs that pull waste out of bee hemolymph. Keepers call the mess dysentery and reach for a Nosema count. This paper says look for both.
Clinical signs that a honey bee colony may be infected with M. mellificae have been observed to resemble signs of a Nosema sp. infection.
Who gets it, and when
Workers are the caste that shows it. The paper has not found it in drones. Queens pick it up in odd setups such as a cage. Spread is fecal-oral. Comb with feces, water with feces, and trophallaxis are the routes they name. Keepers see it more in winter and early spring. By late spring the cysts often drop below what a slide shows, even in a colony that looked sick in February.
Both pathogens shrink the cluster, stain the entrance, and shorten adult life. They often sit in the same box. The paper says the damage can add up. A million spores is the Nosema line. This amoeba has no economic threshold yet. There is no commercial treatment on the shelf. Feed and mite work still matter because a second gut parasite on a hungry, mite-loaded colony is a worse winter.
Count it the same way you count Nosema
Presence is a drop on a slide. A load uses an Improved Neubauer hemocytometer, the same tool as How to Quantify Nosema Spores. Wear gloves. An Improved Neubauer hemocytometer is the load count, the same tool How to Quantify Nosema Spores uses for Nosema. Get this. A scope with a 40x objective to see the cysts. Get this. This page does not sell a drug. The paper says manage mites, inspect, and clean gear between yards so the amoeba is not the only thing you fight.
The entrance is stained. Is it Nosema?
Maybe. The paper says the two look alike and often travel together. Count both on the same crush.
Is there a bottle for this amoeba?
No commercial treatment in this paper. Quarantine, comb swap, and clean gear. Keep counting mites.
Sources
- Monitoring for Amoebic Disease. Gurland, Fulton, Iredale, Vu, and St. Amant. Detection, not a drug.
- How to Quantify Nosema Spores. Same crush and hemocytometer.