This document describes a honey bee brood laboratory toxicity test using repeated doses. It is based on the OECD Test Guideline 237: Honey bees (Apis mellifera) larval toxicity test, single exposure. (1) ring tested in seven European laboratories, which is itself based on a method developed in France (2).
Bee brood frames are composed of brood at various stages of development - eggs, larvae, and pupae. In each cell of honeycomb, the queen lays an egg, gluing it to the bottom of the cell. The queen tends to lay brood in a circular or oval pattern. At the height of the brood laying season, the queen may lay so many eggs per day, that the brood on a particular frame may be virtually of the same age.
As the egg hatches, worker bees add royal jelly - a secretion from glands on the heads of young bees. For three days the young larvae are fed royal jelly, then they are fed nectar or diluted honey and pollen. A few female larvae in special queen cups may be selected to become queens. Their special queen cups are flooded with royal jelly for six days. The extra royal jelly speeds up the queen larvae development. Only the queen will have fully developed ovaries, i.e. she will be sexually mature. Drone brood develops from unfertilized eggs. Drone brood cells are larger than the cells of female worker bees.
Older larvae in open cells. On the lower left is one about to pupate. On the upper right is one partly capped.
Young larvae eat their way through the royal jelly in a circular pattern until they become crowded, then they stretch out lengthwise in the cell. Soon they begin to spin a cocoon, and their older sisters cap the cell as they go into the pupa stage. These cells collectively are called "capped brood." [ (c) eurofins]
