Wasps will behave differently depending on where they are in their life cycle. In order to successfully manage nuisance wasps it is important to understand wasp behaviour and therefore it is important to understand the life cycle of the wasp.

For convenience, the wasp life cycle can be divided into four stages. It is important to understand however, that these four stages are not clearly defined in nature as one stage will cross over into the next as wasps progress through the different stages of their life cycle. Furthermore, the different stages are weather dependant and may vary by as much as three months.

Hibernation

(from as early as the beginning of September to as late as the end of April)

The first stage of the life cycle is hibernation. Wasp colonies die off during the winter months; not because of the cold but because of starvation for a lack of food. Only sexually mated queens over winter by hibernating.

Queens will hibernate in crevices and sheltered places. Most of them will die. Something like only 2 queens will survive to establish successful nests out of every 4,500 queens produced in the prior year. Spiders are responsible for killing a large number of queens because they share the same crevices and sheltered spaces. Warm winters also kill large numbers of queens. Contrary to popular belief, cold harsh winters are actually good for wasp populations. Mild or warm winters see queen wasps coming out of hibernation early when there isn’t any nectar available because plants aren’t in flower. As a consequence, large numbers of queen wasps die from starvation. With long harsh winters, queens stay asleep until plants start to flower when there is ample nectar to support them. Overwintering queen wasps emerge from hibernation when temperatures in the shade reach about 10°C. Occasionally, emerging queens will stray into living quarters of the house, especially conservatories. Modern conservatories manufactured from uPVC have lots of crevices and hollow areas which offer ideal hibernating sites. Many home owners mistakenly assume that they must have a nest when queens emerge from their conservatories in spring and sadly many use pesticides to kill off the queens. The best thing to do is open the windows and allow the queens to escape and then seal up entry points into the conservatory from the outside to make it wasp proof to prevent the problem the following year.

Colony Founding

(from as early as the beginning of March to as late as the end of May)

When queen wasps come out of hibernation they have only one thing on their mind and that’s to establish their colony as quickly as possible. For queen wasps this is a deadly race against time which most of them will lose. Not only do they have to find nectar to feed themselves, they also have to find a suitable nesting place and start building their nests. This requires thousands of trips to collect wood which they pulp into papier mache to build their nests. The first thing the queens build is the foundations of the nursery. Even before the nursery is complete, the queen will lay several eggs to bring on her brood as quickly as possible. The queen will then continue to build her nest and the nursery around her first eggs. All adult wasps feed on sweet liquids that are packed with high energy sugars. At this time of year, queen wasps get their sweet sugary liquids as nectar from flowers making them valuable pollinators. This changes however when the eggs hatch into grubs. The grubs need protein to grow so the queen changes her behaviour. At this point she starts to hunt for other insects so as to feed her brood. What with the queen hunting and collecting wood and building her nest, the queen has no time to feed herself. Nature deals with this problem in a remarkable way. Insect skeletons are made from chitin and chitin is a material made from densely packed and tightly bound sugars. When the grubs in the nest eat insects caught by the queen, they convert the chitin into free sugars which they then re-feed to the queen. This allows the queen to get on with her race to establish her colony without having to find food for herself. Wasps are trully remarkable and intelligent insects. Not only do the grubs help by feeding the queen, they also take over pulping wood for the queen. When the queen collects wood for nest building she gives it to her grubs so that they pulp it into papier mache with their saliva for her. This allows the queen to get on with her other chores.

Colony Growth

(from as early as the beginning of April to as late as the end of November)

Colony growth really kicks of once sufficient worker wasps have hatched to take over the routine chores of the nest. At this point the queen becomes nest bound and her job is to lay eggs and control the activities of her workers. Once the queen is nest bound she has won the race and there is every chance that the nest will make it to maturity. The worker wasps undertake a complex series of tasks. Younger worker wasps keep the nest clean by carrying away and disposing of detritus. Other workers find wood for nest building. Other workers find water which they posit on the outside of the nest to keep the nest cool. Other wasps fan the water to help evaporate it to aid cooling. Other workers go out and hunt for insects and carrion to feed the grubs in the nest. The grubs in return feed the worker wasps with sweet sugary liquid. Other workers work in the nursery helping newly hatched adults to emerge. Other workers guard the nest as sentries. Other workers communicate the orders of the queen and tend to her needs. The nest will continue to grow until the queen decides it is time to produce her new sexual progeny. Up until that time, the colony will continue to hunt for insects helping to get rid of all manner of harmful insect pests.

Procreation

(from as early as the third week of July to as late as the beginning of December)

There then comes a time when the queen decides that the time is right to create her sexual progeny, i.e. the new queens and drones (male wasps) that will carry the species forward into the next year. What triggers this decision is not known but the remarkable thing is is that it is co-ordinated with all of the other wasp nests usually country wide. Producing the sexual progeny takes a few weeks so to coincide with all the other nests requires advanced planning the complexity of which is far from being understood. However, the queen must decide which of her eggs she will fertilize. Unfertilized eggs will form drones. Fertilized eggs will form female wasps (usually workers). The queen then needs to decide which of her female grubs she will change into queens. How she does this no one really knows but it is thought that the queen feeds these female grubs a special hormone. Worker wasps are all female and even though they have not been fertilized they can still lay eggs. Normally the queen will destroy such eggs but at this time of year, she also decides to allow some of these worker eggs to survive. Once the sexual progeny have been produced, they are released at the same time that all the other nests release their sexual progeny. The progeny come together in a mating swarm. When this happens on a hill, the mating wasps are seen rolling down the hill and this is know as hill tipping. Such mating swarms only last for a short time and the drones die off within hours of mating. Where such mating wasps occur on people’s property, the natural reaction is to call a pest controller to eradicate the swarm. Sadly, such actions decimate queen wasp populations for the future and lead to all sorts of rebound pest problems. Given that such swarm last for only a few hours it is much better to leave the swarms alone and allow them to disperse naturally. Once the new queens have mated, they fly off to find shelter in a bid to survive until the next spring. The mated queens do not return to their old nest.

Once the old nest has released its sexual progeny, it is said to have ‘matured’. A matured wasp nest behaves very differently. The old queen stops laying eggs and as a consequence before long there are no grubs in the nest. Without grubs in the nest, the worker wasps don’t get any food and start to starve. It is at this point that the workers then go looking for sweet sugary liquids from other sources. In nature this coincides with the fruit and flowers that are produced by certain plants and trees. It also coincides with the time when we try to enjoy outdoor drinking and dining and it is at this time that the worker wasps become nuisance wasps. Importantly, these nuisance worker wasps are already in decline and are starting to starve to death so eradicating them when they are a nuisance has no effect on future colonies and this is why WaspBane is so ecologically sensitive because it only targets these nuisance worker wasps.