ADAS scientists rear flies to monitor if they are coming from nearby landfill

(30/04/2009)

When the owners of a Scottish landfill site received an upsurge in complaints from local residents who blamed the landfill for the flies that were creating a nuisance inside their homes, ADAS scientists were asked to investigate. Their task was to ascertain fly numbers around the landfill site, and if possible, where the flies were coming from.

To determine through monitoring, information gathering and the creation of a reliable evidence database, whether the problem was actual or perceived, if the flies really did originate from the landfill site, and if so to determine how far the problem might stretch, and what could be done to solve it.

The team reared 50,000 common houseflies, all at the same stage of pupation in their life cycle. These were moved to the landfill site and buried in trays containing sand mixed with an oil-based blue dye. The flies in the trays would pick up small amounts of dye during their emergence process, and could therefore be readily identified. Traps were then set at locations of varying distances from the site and the flies caught analysed to see if they were dye marked.

The results showed that flies from the site were to be found only in relatively close proximity. The data was not only used to determine the extent of the problem, but also to determine trends. It could therefore also be used as an early warning device to ascertain if a problem was on the horizon and allow pre-emptive measures to be put in place at an early stage.

Related categories:  Biodegradable waste   Pollution control technologies