Frame Guide › Disease
Sacbrood: what it looks like on the frame
Spring · a handful of odd larvae scattered in otherwise decent brood.
The larva has turned into a fluid-filled bag with a darkened, up-curled head — like a tiny canoe or slipper lying in the cell. Lift one out with tweezers and it comes whole, sloshing, because the skin never moulted.
Keep the colony strong and requeen only if it persists
Sacbrood is a virus with no treatment, and in a strong spring colony it usually disappears on its own as the bees clear the affected larvae. It's only worth acting on if it drags on, which points at weak hygienic behaviour and a queen worth replacing.
Easy to mistake for
- European FoulbroodMay · built up fast, then stalled. A faint sour smell.
- ChalkbroodCool, wet spring. You spot chalky white bits on the landing board.
- Varroa Mites & Deformed Wing VirusAugust · your alcohol wash came back at 9 mites per 100 bees.
Could you spot this with the lid off?
Read the Frame deals you 8 random frames. Say what you see, say what you'd do, and find out why. It's free and runs on your phone.
Drill disease → Mixed round (all 32 frames) →More disease
- ChalkbroodCool, wet spring. You spot chalky white bits on the landing board.
- American Foulbrood Warning SignsSpotty brood, sunken greasy cappings with pinholes, and an odd smell.
- European FoulbroodMay · built up fast, then stalled. A faint sour smell.
- Chilled BroodYou went through this hive on a windy 48°F day and took your time.
- DysenteryLate February · brown streaks on the top bars and down the comb.
- Foulbrood ScaleA colony that dwindled and died last fall. You tilt a frame toward the light.
These frames are drawn to teach the pattern, and real frames vary. If you suspect foulbrood or a pesticide kill, contact your state apiarist. In Pennsylvania that's the PA Department of Agriculture apiary program. Samples to the USDA Beltsville Bee Lab are free. From The Alleman Apiary in Middletown, PA.