Wasps can become a problem for us and our bees at this time of the year. To understand why and what to do, it helps to know something about their lifestyle. Wasps are carnivorous. The larvae are fed chewed-up insects by the adults and they exude a sweet substance which the adults lick up and from which they obtain much of their carbohydrate intake. When the breeding cycle comes to a close at the end of the summer, the adults no longer have access to their “sugar fix”. They raid our picnic tables and they raid honey from weak colonies.
The fact that wasps eat insects means that they do provide a beneficial service to gardeners in controlling aphids and greenfly during the summer. This function is no longer available at the end of the summer. Most people do not like killing (even!) wasps but you should be aware that the breeding cycle is over and the adult wasps have no further useful purpose to serve and they will soon die (the mated queens hibernate until next spring).
- if your bees are being harangued by wasps, you can do one or more of the following:
narrow the hive entrance to the smallest practicable extent (say 30mm wide)
- ensure that your hives are bee & wasp proof (many old hives have broken corners or joints that are opening or roofs with ventilation openings that once had mesh over them but which are now open to wasps and bees)
- if you’re feeding your bees, do so in the evening and mop up any spills immediately
hang up a large grey bag stuffed with newspaper in your apiary (something the looks like a wasp nest). Wasps will be deterred from coming into the apiary because they will be fooled into thinking that there is a wasps’ nest and they are safer elsewhere. (I guess it doesn’t hurt to try!)
- put up wasp traps. These can come in two forms – traps that kill and traps that trap insects without killing them. The latter are useful if you want to release insects other than wasps that have entered the trap. You will find examples of both on the web – see http://www.nationalbeeunit.com/downloadNews.cfm?id=122 for a trap designed for hornet monitoring but which can also be used for wasps. Bait them with jam, beer – fermenting sweet concoctions of any type.