Subproject E06

Dr. Christoph Häuser, Staatliches Museum für Naturkunde, Rosenstein 1, 70191 Stuttgart, Germany

Lepidoptera as indicator organisms for human impact on tropical rain forest systems in East Africa

Objectives
Occurrence of phytophagous insects like Lepidoptera depend on several parameter of climate, soil-conditions and composition of vegetation. Every type of land use causes various modifications of these sets parameters.
The goal of the project is to describe the diversity of diurnal and nocturnal Lepidoptera in undisturbed, disturbed and fragmented habitats within the Kakamega Forest. This approach will include standardised sampling, determination and statistical analyses. The considered steps are:

•	Description of the association of Lepidoptera species for every selected plot
•	Comparison of the Lepidoptera of different habitats based on the abiotic and biotic factors
•	Identification of indicator species for each type of habitat
•	Development of assessment schemes to assess quickly the current state of biodiversity

For this aim it is necessary to use taxonomically well known families of Lepidoptera. The following families of Lepidoptera seem to be adequate candidates: Pieridae, Nymphalidae, Arctiidae, Saturniidae and Sphingidae. In addition soil parameters will be analysed, which is the basis for recognising changing abiotic conditions and their correlation with biotic facts.

Methods
The database for the final analyses should be a qualitative and quantitative registration of species of the selected Lepidoptera families. The first step is the development of standard methods for collecting and monitoring which can be used in different habiats. Fieldwork will be on two times a year for a period of 4-6 weeks in the beginning and end of the rainy season.
Diurnal Lepidoptera will be recorded along selected transect routes. Recording on the selected routes will be done periodically (three times a week) in a defined time at day. All butterflies seen within the vicinity of the route and within an estimated distance of 5 m ahead from the recorder will be counted. Additionallly, fruittraps will be used on the transect route.
Nocturnal Lepidoptera will be recorded by light with two methods (also three times a week): First, by using lighttraps all over the night; second, by individual observations at artificial light. Furthermore some small samples of soil (100 ccm) will be taken from homogenous patches within the investigated sites for each different type of occurring land use. The samples will be analysed with respect to their physical and chemical components.