This year has seen record numbers of wasps. Common wasps (Vespula vulgaris) or ‘jaspers’ as they are known to country folk, have appeared in plague proportions. Last year, if I remember rightly, there were very few but the same certainly can’t be said this summer!
Apparently there are 9,000 species of wasps in the UK alone and 100,000 identified world-wide. The vast majority are tiny, parasitic and solitary and, in England, the common wasp is the only one that really bothers us. If one is annoying you the best thing to do is stay calm. An angry wasp stings to defend itself and also releases a pheromone attracting other wasps to come to its aid.
Unlike bees, wasps do not store food so cannot survive the winter and they all die, with the exception of a few young fertilised queens. These individually seek out somewhere to hibernate then emerge in spring and set about building walnut sized nests in which each lays around twenty eggs. These hatch out into larvae which she feeds. By May they are mature and become workers. The queen then focuses her attention on laying more and more eggs which in due course also become workers. They expand the nest and feed the ever increasing number of larvae. Surprisingly, wasps do serve a useful purpose at this stage of their life cycle. The larvae need meat and while the workers don’t eat meat themselves they catch insects, aphids, ants and caterpillars to feed them on.
This process continues until August when the queen ceases to lay eggs, apart from a special few to produce males and future queens. She no longer releases the pheromone which stimulates her workers to work. With no larvae to provide meat for they switch to searching for sweet, sugary substances to feed themselves and can also be seen drinking at bird baths and fish ponds. Come the cold weather they, the original queen and the males all die. Only the hibernating, mated queens survive.
Nests may be built in sheds, garages, bird boxes, wall cavities or a hole in the ground. Their location can often be discovered by studying the route wasps take. They are made out of seasoned or dead wood which has been chewed up and mixed with saliva to form a grey, paper-like substance. Beware, nests may be up to 40cms in diameter and contain 10,000 wasps but they really are works of art and well worth taking a close look at once they’ve been abandoned.
Professional pest controllers and local councils charge to dispose of active nests. Alternatively proprietary brands of powder or foam aerosols are available over the counter which, if used as instructed, can be effective. However, great care must be taken. Protective clothing should be worn and the nest only treated in the cool of late evening or early morning when the wasps are least active. If powder is used it should be put in place using a spoon tied to a long stick.

Ron’s Rambles

Air Conditioning
Many of us have been very pleased in the recent hot weather to have been, at times, in places where there is air conditioning. In our cars, in supermarkets and in offices and other places. It is rather strange that whilst it is considered worthwhile to install air conditioning in these places it does not seem to be worthwhile for most people to install it in their homes. I have said ‘air conditioning’ as that is the popular description of ‘air cooling’ because most of these systems are simply air coolers. Strictly speaking one could only justify using the term ‘air conditioning’ if there was some control over humidity as well as temperature. One might go further and suggest that ‘conditioning’ should also include filtration. Air cooling requires nothing more than a refrigerator plant similar to that used in domestic refrigerators and freezers and it is obvious that a cooler for air cooling should not be significantly more expensive than friges and freezers, so why haven’t we got more in our homes? There is one problem, just as with friges and freezers, there will be some heat generated, this is the heat extracted from the air, the moisture in the air and the heat generated by the motor and it all has to go somewhere, one cannot put it back into the room that one is trying to cool, if you do you will be heating the room, not cooling it. Of course with a cooler in the room there would be some water condensing on the cooler and this may have the effect of lowering the relative humidity in the room and that could make it a more pleasant atmosphere but, unless the heat produced was extracted from the room, the temperature would not fall. A proper cooler therefore needs to have an exhaust from the room to take the heat away. That implies a small increase in the cost because of the need to make a hole through the outer wall and install a pipe with a suitable guard at the outlet to keep out unwanted pests, furthermore it makes the cooler into a semi-permanent fixture.
It is surprising, however, that no manufacturer seems to have produced a low-cost portable cooler with a flexible exhaust pipe, perhaps with a broad flattened end, that could be put out of a window. I am sure there are many people who would have been very pleased to have had such a device in their bedrooms during this recent very hot weather. The same device could be used to good effect in the lounge in the evenings.
Of course it is possible to buy low cost coolers of the evaporative type, these you top up with water, the water is drawn into a porous material and air is blown over that. The water is evaporated taking heat from the air and producing a cooling effect. This water is absorbed by the air and the absolute humidity of the air is increased as a consequence, the relative humidity is also increased because of the increase in humidity but also because of the lowering of the temperature. How much benefit one obtains depends on the relative humidity of the ambient air, if the ambient relative humidity is high the rate of cooling is reduced and the relative humidity in the region of the cooler becomes even higher.
Some new houses have had air to air heat pumps installed in place of a boiler and some installers are offering these heat pumps for retro-fit. These are essentially refrigerators that are cooling the external air and using the heat extracted to heat the building. They have the potential ability to provide the convenience of electricity with the running costs of a boiler or less. Anyone considering the installation of an air to air heat pump needs to be wary because some of these units are not achieving the performance promised. Properly installed, however, these heat pumps have the potential ability to be reversed so that they can deliver cool air in the summer.

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