Japanese Honey Bees
Apis cerana japonica
Japanese honey bees are members of the same genus as the European honey bee (Apis). They are members of the Asian honey bee species Apis cerana and make up the subspecies of Asian honey bees known as Apis cerana japonica. The best way to describe the appearance of Japanese honey bees is to compare them to the more familiar European honey bees. Japanese honey bees complete their development via complete metamorphosis (egg, larval (grub), pupal (cocoon), and adult stages). The appearance of individuals making up a honey bee colony differ based upon the stages of development (eggs, larvae, pupae and adults), as well as the looks of different members of the three castes of the colony – queen, drones and workers.
The bands on the abdomen of Japanese honey bees are more noticeable than those of European honey bees, plus Japanese honey bee workers have four bands, while European honey bee workers have only three. Queens are the reproductive females of both colonies. They are larger than the workers, have larger abdomens that contain their developed reproductive organs and are generally slightly darker than the workers. Drones are large-eyed bees that have no stingers. Their abdomens are thick and blunt at the end. A very distinctive structure on the workers is the “pollen basket” located on their third set of legs that helps in collecting and transporting pollen.
BEHAVIOR, DIET & HABIT
Japanese honey bee worker adults feed on nectar and pollen produced by plants, and foraging for food is critical to the process of transferring pollen from one plant to another. Pollen is one of the purest and richest natural foods, containing all of the nutritional requirements of a honey bee: sugar, carbohydrates, protein, enzymes, vitamins and minerals. The larvae consume honey, and the queen larvae and adults eat royal jelly, which contains dietary supplements for the adults and a fertility stimulant for the queen.
There are several factors that make Japanese honey bees very good pollinators. One is their smaller foraging range compared to other honey bee species. A smaller foraging area means that each worker spends more time on the same plants, so they have a greater opportunity to “pollinize” the plants they visit. Also, Japanese honey bees generally have a longer daily foraging period than European honey bees. A Japanese honey bee colony consists of one queen, many thousands of workers and many drones. The role of each caste is much like that of most other honey bee colonies. The queen’s role is to lay eggs and keep producing the colony’s needed workers. The drones’ role is to mate with the queen, and the workers build the hive; nurture the eggs, larvae and pupae; keep the hive clean, forage and produce honey.
Japanese honey bees often nest in man-made structures, but normally prefer to build their hives in natural cavities such as hollowed out tree trunks, rock crevices and caves. While Japanese honey bees will sting in order to defend their nest, they are less likely to do so than European honey bees. Bee keepers raising Apis cerana japonica generally keep bee hives in boxes, logs, clay pots, and wall openings.
A queen laying fertile eggs initiates the Japanese honey bee’s life cycle. The queen lays a single egg in each of the hive’s brood cells, and the eggs hatch into larvae after about 2-4 days. Newly hatched larvae curl into a C shape at the bottom of the brood cell, are fed and grow until they are large enough to pupate, at which time the workers cap each cell. After the pupal stage is complete, new adults chew their way out of the capped cells and soon begin performing their respective worker-related duties.
Reproduction for a Japanese honey bee colony is similar to most other species of honey bees. This involves queens mating with drones and occurs when a colony’s queen is no longer fertile and needs to be replaced or the queen and a part of her colony absconds (breaks away) to a better, less competitive location.
When colonies are large in size or have abundant resources, they will swarm, sending adult workers to establish another colony. When conditions favor this, the colony’s mother queen will lay 10-20 eggs in specialized brood cells called queen cups. These queen cups house daughter queen pupae that develop from larvae that were fed more royal jelly. When daughter queens are in their late pupal stage, the mother queen and up to about 2/3 of the adult workers leave the colony in search of a place to establish a new colony.
Within an existing colony, it may become necessary for a new queen to replace an existing queen or replace a queen who left with a portion of the hive that absconded. When queen replacement is necessary, non-fertile, virgin daughter queens are produced as mentioned above, and they fight with and kill other daughter queen adults or pupae. This battle continues until only one virgin queen is left alive. The sole remaining daughter queen is unmated, so she temporarily leaves the colony to mate with multiple drones. Once mated, she returns to her colony and produces fertilized eggs for the remainder of her reproductive life.
SIGNS OF A JAPANESE HONEY BEE INFESTATION
Observing the workers, evidence of honey coming from a hive, or getting stung are most often signs of a honey bee colony. Also, anytime one sees a constant procession of honey bees into and out of an opening leading to a wall void, a tree or another such preferred honey bee habitat site, you can be sure of the bee’s presence.
Using modern DNA testing procedures, bee researchers have shown that Japanese honey bees originated in the Korean peninsula and are now natives to Japan.
Controlling Japanese honey bees is something that should be considered only when there is no other practical and effective way to reduce the risk of stings.
Japanese honey bees exhibit an amazing behavior called bee balling. Should their hive be invaded by a predator such as the Japanese giant hornet (Vespa mandarinia), several hundred Japanese honey bees form a ball around the hornet and vibrate their flight muscles to produce heat. As this continues, temperatures surrounding the hornet are raised to 117 degrees F, a temperature that is high enough to be lethal to the hornet, but does no harm to the honey bees.