Wednesday, January 14, 2009

Paper Wasps
Paper Wasp, common name for medium- to large-sized wasps that construct nests made of a papery material. The nests consist of a single upside-down layer of brood cells or compartments for the young. Paper wasp nests resemble an upside down umbrella of cells and are often found hanging under the parts of buildings, in attics, trees, as well as other structuresMost paper wasps measure about 2 cm long and are black, brown, or reddish in color with yellow markings. Paper wasps will defend their nest if attacked. Adults forage for nectar, their source of energy, and for caterpillars to feed the larvae (young). They are natural enemies of many garden insect pests.
The nests of most species are suspended from a single, central stalk and have the shape of an upside-down umbrella. Some tropical species make nests that hang in a vertical sheet of cells. Wasp collects water droplets from nearby water source like this in the photo. The paper wasp builds clusters of hexagonal paper cells. Mixing masticated wood pulp with adhesive saliva, these paper nest cells act as larval nesting chambers for the young wasps. The Chinese inventor of paper was legend to have been inspired by observing these wasps chewing bark. Other members of the Vespid family, are potters, building their nests from mud and saliva. The nests are constructed in protected places, such as under the eaves of buildings or in dense vegetation. Normally a colony of several to several dozen paper wasps inhabits the nest.
In most species of paper wasps, colonies are founded by one female who dominates the colony and lays most of the eggs. This female constructs the nest, lays eggs, forages, and raises the first generation of offspring. She then stops foraging, becomes the queen, and rules by dominating her offspring of workers. This is a classic dominance hierarchy with the queen maintaining control through aggressive interactions. Each individual in line maintains dominance over all others below her through confrontation and aggressive interactions. If the queen dies or is otherwise lost, the most aggressive worker takes over. This worker begins laying eggs and continues to dominate all below her. Since the workers have not mated, they can only lay unfertilized eggs, which develop into males, a typical trait in wasps.
Some queens that are unsuccessful at establishing their own nest may join another queen, submitting to her dominance and becoming a worker. Studies have shown that such individuals, called joiners, are most often sisters of the queen. Since this individual mated the previous fall, her eggs can develop into workers and she could become the next queen if the founding queen is lost. Occasionally a joiner dominates the founding queen and takes over the nest, a behavior known as usurpation. In such rare cases, the usurper becomes the queen and the previous queen becomes a worker.
Yuwaraj Gurjar.

1 comment:

  1. Beautiful photo, but the "paper wasp" at the beginning of this entry is actually a fly. It is a paper wasp mimic, and evidently a pretty convincing one!