How can beekeepers guard against camellia nectar poisoning in honeybees?

1. Causes

Test analysis has determined that camellia nectar, besides containing trace amounts of caffeine and glycosides, mainly contains a relatively high proportion of polysaccharide components. Toxicity experiments show that camellia nectar is not toxic; the cause of honeybee poisoning is that honeybees cannot digest and utilise the oligosaccharide components in camellia nectar, and in particular cannot utilise the bound galactose component, causing physiological disorders.

2. Symptoms

Camellia nectar poisoning mainly causes the death of honeybee larvae. The dead larvae have no definite shape and no foul odour, clearly different from the larval death symptoms caused by pathogenic microorganisms.

3. Rescue measures

Adopt partitioned colony management combined with medicinal detoxification, so that the colony can both make full use of the camellia nectar source and consume as little camellia nectar as possible, thereby reducing the degree of poisoning. Partitioned management is divided, according to colony strength, into two methods: super-chamber partitioned management and single-hive partitioned management.

(1) Super-chamber partitioned management

This measure is suitable for relatively strong colonies (6 frames of bees or more). The specific method is: first use a divider board to separate the brood chamber into two zones, move the honey combs, pollen combs and an appropriate amount of empty combs, together with the queen and bees, into either zone of the brood chamber to form the brood-rearing zone, then move the remaining combs together with the bees into the other zone of the hive and into the super chamber to form the production zone (honey and royal jelly are harvested in this zone). The super chamber and brood chamber are separated by a queen excluder, so that the queen cannot pass through while worker bees can move freely in and out. In addition, in the brood-rearing zone, apart from the edge comb near the production zone, a honey-pollen comb and a frame-type feeder should also be added respectively, so as to provide artificial supplementary feeding and prevent the bees from carrying camellia nectar into the brood-rearing zone. The entrance is opened in the production zone, while the entrance on the side of the brood-rearing zone is fitted with a wire-gauze entrance controller, so that bees can only leave and cannot enter.

(2) Single-hive partitioned management

Separate the brood chamber into two zones with a wire-gauze divider board, then move the honey combs, pollen combs and an appropriate amount of empty combs and sealed brood combs, together with the queen and bees, into either zone to form the brood-rearing zone. The other zone forms the production zone. Cover the top with a gauze cover, and note that a gap of 0.5-0.6 cm should be left between the divider board and the gauze cover, so that bees can pass freely while the queen cannot pass through. In the brood-rearing zone, besides adding a honey-pollen comb at the edge frame near the production zone, also add a frame-type feeder near the divider board, to serve as artificial supplementary feeding and to prevent the bees from carrying camellia nectar into the brood-rearing zone; however, on the top bar on the side far from the production zone, a bee space should still be left so that bees can move freely in and out. The entrance is opened in the production zone, and the entrance on the side of the brood-rearing zone is fitted with a wire-gauze entrance controller, so that bees can only leave and cannot enter, and the foragers that come out can only enter the production zone; in this way the larvae in the brood-rearing zone are prevented from dying of poisoning, achieving the purpose of rescue.

(3) Combining medication with feeding management

First, in the brood-rearing zone, spray or drench each evening with detoxifying medication containing a small amount of syrup (0.1% multienzyme tablets, 1% ethanol and 0.1 rhubarb soda); feed every other day with 1:1 syrup or honey water, and take care to supplement an appropriate amount of pollen. Second, in the honey-collecting zone, take care to harvest honey at the right time. During the peak camellia nectar flow, generally harvest honey once every 3-4 days; if the colony is relatively strong, royal jelly can be produced or a virgin queen can be used for honey collection. Spray-feed with detoxifying medication syrup once every 3-4 days.