Urban Insect Pest Management: Implications for Insect Conservation

Abstract

The major interest of ‘Urban entomology’ developed largely from concerns over pest insects and ways to eradicate or suppress them in and near human dwellings and settlements. Pest problems are still a major entomological focus in urban areas, but their long domination of interests in urban insects, emphasised by Frankie and Koehler (1978), has lessened considerably, although insect pest management remains an almost universal priority theme in urban environments as the variety of insect impacts on human wellbeing continues to diversify. Many insect groups, including numerous innocuous forms, are first noticed by people in urban environments, and the many insects that are associated in some way with anthropogenic regimes lead to increasing practical and psychological concerns, with efforts to suppress them as putative ‘pests’. Other than those causing direct tangible damage or injury, many ‘urban pest insects’ are essentially defined as such by peoples’ attitudes and reactions – urban people ‘define under what circumstances insects are a problem’ (Dreistadt et al. 1990), so that aesthetic factors such as appearance are added to (or replace) features such as economic injury or loss. Domestic pests, those found mainly in buildings, benefit from a narrow and relatively stable range of climate conditions and from assured shelter and resources. Both domestic pests and the larger array of ‘periurban pests’ (Robinson 2005) persist largely through the presence of reservoir populations and habitats across the landscape, from where colonisation of homes and gardens can be easy and frequent. Their management includes attention to those habitat networks – examples such as pest mosquitos breeding in small water pools such as abandoned swimming pools and rain collected in discarded cans or tyres, wasp nests on old walls or in tree cavities, and cockroaches in water pipes are cited commonly, but almost any natural vegetation or anthropogenic feature can be exploited by insects. Many pest insect species are widespread and, whether native or (as commonly) alien, their impacts may transcend rural and urban environments. A number of generalist feeders, most commonly herbivores, can affect commercial plantations or forests and amenity or garden plantings (including ornamentals, lawns, vegetables, street trees, and many other plant categories) alike, across a variety of scales and environments. Their impacts are thus scale-related: the smaller areas affected by widespread agricultural or forestry pests in urban areas may demand clearly focused management, and the range of treatment options available for use over large areas be restricted.