Fly populations associated with landfill and composting sites used for household refuse disposal

Calyptrate fly populations were monitored with sticky traps at the followin g sites in Hampshire, UK during August to November 1998: a landfill and com posting site (Paulsgrove), a site adjacent to this landfill (Port Solent), a site with no landfill nearby (Gosport), and a composting site with no lan dfill nearby. Overall, house flies Musca domestica (Linnaeus) and lesser ho use flies Fannia spp. were not important constituents of the dipteran catch , while bluebottles (Calliphora spp.) and greenbottles (Lucilia spp.) compr ised approximately 12% of the total. Very large fly populations were found at the two composting sites, and it seems likely that these provide ideal b reeding grounds for a range of fly species since they offer an abundance of warm decaying organic matter. Large fly populations were also evident at t he landfill site. The suitability of household waste for the development of calyptrate Diptera was confirmed in a controlled trial: a mean of 0.43 adu lts emerged per kilo of one-week-old waste. Since many hundreds of tonnes o f waste are delivered to the landfill daily, it is clear that the landfill is likely to substantially increase the local population of calyptrate flie s. However, the data suggest that there was little movement of Diptera from the landfill to Port Solent situated approximately 500 m away. The most im portant calyptrate flies at this site were the cluster flies Pollenia rudis (Fabricius) and P. amentaria (Scopoli); the landfill site is unlikely to p rovide a suitable breeding site for these flies, as the larvae develop as p arasites of earthworms. Significantly more flies emerged from one-week-old than from two-week-old household waste. A comparison of different barriers to the emergence of adult house flies from waste demonstrated that sacking provided an effective barrier to fly emergence, but that soil did not diffe r significantly from control treatments. If managed appropriately, it seems that the use of sacking over landfill waste could substantially reduce ass ociated fly populations.