Wasp

Common Name: Wasp
Scientific Name: Vespula vulgaris

Introduction: The Common wasp or German wasp is commonly found throughout Britain and Europe. They become a nuisance during mid summer and are also known for their aggression and painful sting. Common wasps are yellow and black in colour and in urban areas mostly found in the roof spaces or loft, shed etc.

Recognition: It is very easy to find out if there is a wasp nest in your local building or structure, because wasps can be seen going in and out into the building or structure during the day or the nest can be spotted by the occupants using the building. Sometimes the wasp can be confused with bees due to wrong identification. Bees are normally shorter in body length (about 15mm) and very chubby in size whereas the wasps are slimmer and longer in body length (about 20mm).

Biology:Egg>lava>pupa>adult. During winter fertilised queens goes into hibernation and will emerge in mid April in search of a suitable site to start her colony. The fertilised queen will chew dry timber and plant fibre, mix it with saliva to form her first cell with 10-30 individual chambers. Inside this cell she will lay her first set of eggs averaging 10-30 eggs. These eggs will hatch into white legless grubs where the queen will feed them with insect and other invertebrate. The fully grown larvae takes within four weeks to reach the pupa stage and another two weeks from pupa to adult. These first set of workers or sterile females will take up their places in expanding the nest and searching for food to feed the new set of larvae, while the queen continues to lay her eggs. By late summer a German wasp nest can contain about 3000 individuals with a nest sized of 30cm wide. During the latter part of the summer the males and young queens will emerge when mating begins. The fertilised females will fly away in search of their individual site for their new colony while the remaining workers become sluggish. They feed on ripe and over ripen fruits which cause a tipsy behaviour leading to aggression when interferred with. During the cold winter weather all the workers and males are killed off, with only fertilised queens surviving through hibernating and will start their new colonies during spring.

Habits:common wasps form their nest in soil banks, roof space or lofts, cavities and trees. Their nests are made out of paper (chewed wood and plant fibre). Colonies can only survive one season in Britain with a new one starting each spring.

Potential Harm: Common wasp are known for their painful or unpleasant sting. Multiples sting in sensitive places such as the head or inside the mouth can be serious. In some cases individuals whom are allergic to wasp stings can result in anaphylactic shock (an extreme reaction to toxins in the wasp venom)

Potential Control : wasps can be treated using various insecticide formulations, such as residual insecticide, aerosol spray and insecticide dust (only approved insecticide should be used for pest control in London).