Insects and the determination of priority areas for biodiversity conservation in KwaZulu-Natal province, South Africa

The KwaZulu-Natal Nature Conservation Service is undertaking a long-term project to determine the value of untransformed land for biodiversity conservation, to map these areas in accordance with their relative values, and to identify and prioritize irreplaceable areas. The overall goal of the initial stage of the project was to use existing data and expertise to define areas of conservation importance in KwaZulu-Natal. The aim of this paper is to illustrate the procedures used to incorporate insect species and subspecies into the project, including those for identifying insects of conservation concern and for making a first assessment of their distribution and conservation status. A biodiversity hierarchy (from landscapes through ecosystems and communities to species and populations) forms the basis of the analysis. Information received from taxonomists working in South Africa in response to a questionnaire survey was used to choose the species for inclusion in the initial analysis, A total of thirty-seven species and subspecies endemic to the Province in certain families of Coleoptera, Diptera, Lepidoptera, Mecoptera and Odonata were included. Existing distribution data were collated and the potential distributions of the endemics were modelled at a scale of 4 ha. Factors that potentially influence the distributions of the endemics were gleaned from the literature. Database queries using distribution data with a spatial resolution of: 250 in and cartographic overlays formed the basis of the modelling procedure. Two areas with little or no statutory protection, the high-lying grasslands of the northwestern region and much of the central region of the Province, are predicted to have a relatively high diversity of endemic insects. Fifty-one percent of the insect species and subspecies in the analysis met the two conservation goals, i.e. 1) at least 10% of their present distributions under formal conservation management, and 2) three such protected areas with viable populations. A benefit of modelling the potential distributions of endemics is that searching for populations of these insects can be directed to areas where they are expected to occur. The data collected can then be used to improve the distribution models for these insects, some of which are poorly known. The distributions and their associated conservation targets form a vital component of the iterative systematic conservation planning project currently underway in the Province.