The Death of a Thousand pinpricks
E28 is born a worker in a colony at war. It struggles for its life against a destroyer that cannot be stung to death. Unlike the wasps outside this enemy cannot be dragged from the hive. E28’s colony has been infected with a disease.
E28 was at the entrance of the hive greeting foragers on the day the destroyer arrived. Not old enough to be a guard bee, she hangs back waiting for the foragers who pass the test of the guard bees. She will take their pollen and nectar and transfer it up into the colony. The foragers are freed to return to the hazardous fields, risking their lives with each trip for the sweet prize.
On this day a old forager lands on the board and brushes past the guard bees. Her hair is worn off and her wings are near destroyed but her crop is full – of honey! This forager found some unguarded gold and has stolen it for her own hive. She cannot know that in her crop she bears the the seeds of destruction.
The honey she brought back is deposited in a cell at the edge of the brood nest, where nurse bees wait to dilute it and pass it on to the brood. Before the night is over the first larva is infected.
A few days later that larva stretches out along its cell and dies, its nose contorted upward. A nurse bee stops to check the cell and discovers the dead larva. It is pulled from its cell and cast from the hive, but by now the contagion is everywhere. Each time an infected nurse bee visits a larva, each time it offers food, it leaves a trace of death. In a week the infection is full blown.
The bees are not complacent. They respond with every ability they have. The nurse bees redouble their checks on the larva and they are merciless with removing any that show the slightest hint of disease. The queen lays as often as cells are available and with time the infection is slowed. Though most larva die before their cells are capped some do not. The larva trapped with the disease have no escape during their metamorphosis, so the colony responds by tearing the capping from their cells and dragging them away. Fighting this disease saps the colony of strength. Without a constant influx of new workers the foragers have been depleted.
The house bees are kept at their stations by the pheromones issued by the foragers. Without this scent they long to venture out themselves, but the colony needs them in the brood nest, where this war will be lost or won. Without new stores coming in it the war becomes a three way race. Disease will claim the colony if it can, but starvation looms closely. The deciding battle will not be one of stings and wings, but eggs and tiny larva. The bees cannot win through wrestling, but through constant vigilance. Their will is unlimited. Their stores are not.
E28 is ancient now, nearly seven weeks old. For a summer bee she is so old that there are few like her left. She has been caring for brood and ignoring the call of the blooms for her entire life. The brood nest is expanding. With each day fewer larva are pulled from their cells. With each day new workers hatch to aid in the war. It is to E28’s surprise that one day she moves from cell to cell and bumps into nurse bee after nurse bee. As she retreats down the comb she realizes that she has passed the edge of the brood nest. The entrance lies only a few inches away. On the floor below a forager enters, one of the few. She is transfixed.
This new forager waggles fiercely, walking a line and shaking the whole time. To E28’s instincts these are clear directions of an area. The ferocity of the dance makes her tingle and she bursts forth from the entrance to the hive and flies away. Instinct creates from the sun and the dance a map to this promised land of nectar. It is a field of golden rod.
She is not capable of flying faster than she does, each flower holds the promise of a new bounty. Again and again she fills her nectar crop, over and over she packs her pollen baskets full. Each time at the entrance bees are waiting for _her_. She is finally released to roam the wild waves of flowers, and the goldenrod is everywhere.
She pauses in the late afternoon on a broad pedal to clean herself. In that warm autumn sun E28 dies. With her dies the memory of how the colony beat back the plague, and her death far from home keeps the disease that still lingers in her gut at a distance. Her colony will forever fight this war. Disease has come to the colony and it will lurk at the edges and corners for as long as the colony survives. Other bees will own that struggle, and others face that fight. For E28 the battle is won.
The view from the House
Disease is an ever present threat to the welfare of a colony, but most diseases can be overcome. In E28’s case European Foulbrood is the name of the disease. Its cousin, American Foulbrood, is so deadly that the treatment involves burning the affected hive, sterilizing all tools, and often destroying neighboring hives or entire yards. European foulbrood is not the same class of disease. It often shows up in colonies already under stress. The larvae die, contorted in their cells, twisting, writing as the virus ravages them. They stink like rotten fish. Those that live to be capped die there, trapped under wax lids with their destroyers.
Stress, in this case, would be a weak or low laying queen. When a colony is strong, the affected larva are removed so quickly that the disease has trouble progressing. If the colony is weakened foulbrood gains a toe hold. Bees have six legs, so that's a lot of toes to hold onto.
Foulbrood can also rear its head in the spring. When a queen begins laying in a weak hive, the workers can't care for the number of eggs she lays. There simply aren't enough nurse bees to care for the sudden rush of larvae arriving. What has to happen is that a small wave of nurse bees hatches, followed by larger and larger waves, until the brood nest is roaring, crawling, covered in bees of every age and type.
If a disease takes hold in a weak hive, the first wave of workers is stunted, tiny. There may just barely be enough hatched to replace the bees that died caring for them. These bees are rapidly forced to begin foraging, long before they are ready. The alternative is starvation.
Foraging bees cannot care for larva, meaning that the next wave is small. And still, the disease lingers, growing stronger as the work force shrinks. Now there are not enough workers to remove the infected larvae, and new larvae hatch to an environment so tainted with the disease, their chance of survival is miniscule. The cluster shrinks, and the chill of the night claims more of the unborn.
The Hive at Home
Foulbrood is just one of many diseases which can plague a hive. To take a tour of brood diseases, we begin with those without a pathogen –
Chilled Brood: Chilled brood are exactly what their name implies – brood which could not be kept warm enough. Bees heat or cool the brood nest to a constant 90 degrees. An uncapped larva cannot survive longer than a few minutes without its nurse bees to warm it. Chilled brood is often a sign of a weak colony that cannot care for all its brood. If the colony is weak, a follower board can be used to reduce the space the bees need to heat. Just don’t pack them in and forget to remove it later. Chilled brood is also common in the early spring. Nights are still very cold, but with the colony expanding sometimes the broodnest grows further than the nurse bees can maintain. Particularly if you spot chilled brood after a warm stretch followed by a cold snap, don’t be alarmed. The colony will probably be fine.
American Foulbrood: American Foulbrood is one of the most contagious diseases of the honeybee, and a sure destroyer of an untreated colony. AFB kills the brood after they are capped in most cases, causing a pattern of sunken and perforated cappings, as well as a spotty brood pattern. AFB is called “Foul” brood because it smells horrible. The scent permeates the colony and can often be detected just from sniffing the open hive. The best test for American foulbrood is the “rope” test – take a match stick or toothpick and remove the sunken capping from a dead larva. Poke the match stick into the brood and pull it straight out. If the gooey slime ropes outward for half an inch or more, it’s American Foulbrood. AFB can be treated with antibiotics, but the hives are often destroyed. To destroy a hive the bees are killed with sulfur gas and the frames are burned or buried. The hive bodies can be scorched with a blow torch and re-used. Keep in mind that you cannot out wait AFB – if you put infected equipment to the side, your grandchildren could pick it up and have a ready source of disease to kill their colony.
European Foulbrood: European foulbrood is virus based and is not nearly so destructive as American Foulbrood. Often considered a stress disease, EFB can only weaken a colony, and can only gain a toe hold when there is an extended break in brood rearing. EFB does not require burning the equipment but many beekeepers rotate brood frames out after an infection. European foulbrood is characterized by spotty brood pattern (caused by dead larva), sunken cappings with perforated tops, and dead brood which smells like rotten fish. Unlike American foulbrood, you may need to pull out a dead larva and squish it to smell the odor. Once you do you will never forget it. EFB larva often die longways in their cell with the larva twisted up. Unlike AFB European foulbrood infected larva do not rope at all.
Chalkbrood: Caused by a fungus which first devours the larva’s food causing it to starve, then moves on to consume parts of the larva’s body, leaving a white chalky casing behind. Chalkbrood is often associated with humid conditions and lack of ventilation, so propping open a top enough to allow some airflow can aid in chalkbrood battles.
Stonebrood: Stonebrood is another fungal disease which causes the larvae to mummify into a rock hard shrunken version of itself which looks quite bizarre. Similar to Chalkbrood and EFB, failure to fight off chalkbrood is a symptom of a weak hive than a sole destroyer.
You may be wondering why nosema, parasitic mite syndrome, or other pest caused problems aren’t listed. We’ll get to those in due time, when we look at Mites and Men.