Bee Biology
Early egg processes
Larval Development
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Bee Biology Early egg processes Larval Development |
Development of Honey Bee Eggs
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Honey bee eggs are very small and white, they have the appearnce of a miniature grain of rice that is slightly curved. Each egg is not much longer than a typewritten dash ( - 1.2 mm long) and they are light in weight at 0.12 -0.22 mg.
Eggs are fairly durable and are attached to the bottom of the cell with an adhesive secreted by the queen. It is always positioned small (tail end) end down. The cell acts as a protective receptacle while embrionic development takes place.
The next three days are usually reported as being a time during which the egg gradually leans over until it lays on its side on the cell base. Some texts even say that you can tell how old an egg is by looking at the angle.
This is absolute balderdash and has been propagated down the ages through badly researched books.
Very little egg movement takes place during most of the 72 hour normal development period. If you had time lapse facilities you might see very slight alterations in curvature of the egg, but they are minimal. Movement of the egg to lay flat does not start until the chorion (the egg's outer membranous covering) actually starts to dissolve as the larva 'hatches'. This dissolved 'eggshell' is consumed as food by the larva, but may have royal jelly added to it before it is totally consumed.
An egg normally develops in 72 hours, but this time can vary between two to six days. Temperature variations affect the length of the egg's development time.
The egg is filled with cytoplasm, a nucleus, and a yolk. The nucleus is near the big end of the egg and plays a major role in the development of a future bee.
During the first stages of development before the egg hatches, the nervous system, the outer covering and the organs of the digestive system are formed. The egg remains in an upright position (with the soon to develop head on top) for three days then gradually leans onto its side.
During the first day, the egg nucleus divides-if the egg is unfertilized; or if the egg is fertilized, the fusion nucleus or zygote divides. It is not until the third day that the embryo form (with head and body segments) can be seen within the egg. The head is present at the larger unattached end and the back (dorsum) is on the incurved (concave) side.
The first sign of hatching occurs when an egg is 72 to 84 hours old. Muscular contractions by the embryo cause a gentle, weaving motion that apparently results in a tiny hole being torn in the outer membrane (chorion). Fluid from within the egg soon emerges and covers the external surface. The embryo with its "tail" attached to the base of the cell continues to move about until its head also touches the base and an arch is formed. In this "croquet wicket" stage, the chorion evidently is dissolved. The larva then eases itself over against the bottom of the cell into the familiar C-shaped position).
Size of the honey bee egg (D: 0.3 mm, L: 1.6 mm) and the long preblastoderm stage (11-12 h)
Dave Cushman.
Page created 21/08/2002
Page updated 01/12/2022