27 de maig 2016

LIFE CYCLE OF APIS CERANA

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Apis cerana is holometabolous; meaning individuals undergo four distinct life stages (egg, larva, pupa, and adult). 

Eggs: The queen lays a single egg in each brood cell. Eggs are small, white, and oval in shape (Fig. 5). Larvae emerge from eggs after three days.

Larvae: Newly hatched larvae curl into the shape of a C at the bottom of the cell. Larvae are white in color, blind, and legless, with a wet shine (Fig. 5 and 6). The larvae are fed brood food and/or royal jelly within their cells until they are large enough to pupate, at which time the adult worker bees cap the larval cells.

Pupae: The larvae molt into pupae beneath the wax cappings and the pupal cells are undisturbed until pupation is complete. The wax capping of the drone pupal cells in Apis cerana have a distinctive pore (Fig. 7). The purpose of this pore is not yet known. However, another species of honey bee, Apis koschevnikovi Buttel-Reepen, constructs a similar pore on the drone pupal capping. 

Adults: Following their pupal development, the new adults chew their way out of their capped cells. 

Honey bees are considered superorganisms, wherein the whole colony is considered the biological unit rather than are the individual bees. Colony-level reproduction is referred to as swarming and it generally happens in the spring and summer. However, swarming may be more frequent in tropical areas where climate is more favorable year-round. Abundant resources (nectar and pollen) and large colony size are thought to be the primary triggers for swarming. To initiate swarming, the colony will raise 10 to 20 daughter queens. When the daughter queens are in the late pupal stage, the mother queen and up to two-thirds of the adult workers leave the colony in search of a place to establish a new colony (typically a cavity like a hollow tree).

Once the daughter queens emerge as adults, they fight until only one queen remains. The remaining queen is unmated and must leave the colony on mating flights where she will mate with upwards of 20 drones. The sperm the queen collects is stored in a special organ called the spermatheca and is used to fertilize eggs for the rest of her reproductive lifespan.

The sex of each bee is determined via haplo-diploid sex determination. In this system, the queen decides the sex of her offspring by laying unfertilized or fertilized eggs. Unfertilized eggs (no paternal genetic contribution) develop into drones, and fertilized eggs (both maternal and paternal genetic contributions) develop into females. The female larvae further differentiate into workers or queens based on the diet they are fed. Female larvae that are fed the standard diet of pollen and nectar (brood food) become adult workers. In contrast, female larvae that are fed royal jelly develop into queens. 

 http://entnemdept.ufl.edu

 Photograph by Alexander Wild.