Abstract. 1. Weekly samples of Malaise trapped Coleoptera from regenerating shrubland and an adjacent mature, podocarp‐broadleaved forest, in the North Island, New Zealand, were compared over one season. Three traps were monitored in each site. 2. Diversity indices did not group samples by site whereas the divisive polythetic classification analysis TWINSPAN showed that the two sites possessed clearly different communities. In the classification, site was of primary importance, with time of year, and trap position within site of secondary and tertiary importance respectively. 3. Samples were compared at different taxonomic levels and using different subsets of the database. Determination of the main families, morphotyped to species or species complex, was found to be sufficient to classify most samples to the appropriate community group. 4. The divisive classification procedure applied to four consecutive weekly Coleoptera samples over early summer, is suggested as a means of describing and identifying terrestrial arthropod communities characteristic of site and year of collection. This approach provides a potentially sensitive tool for monitoring terrestrial ecosystems.

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Forest dieback in the Kaweka Range appears to be a stage in the natural process of replacement for mountain beech. An examination of stand structure in stable, transitional, and unstable forest showed dieback and tree mortality to be associated with mature and over mature stands. Recruitment peaks suggest periodic natural disturbance, such as severe drought, initiates tree decline. Insects and disease, although contributing to the rate of decline, were shown to be symptoms rather than causes.

An investigation into the decline of hard beech on the Mamaku Plateau showed tree death to be due to a loss of new foliage over successive seasons. Severely affected trees shed more than 30% of newly flushed foliage as a result of attack by the leaf-mining weevil Neomycta pulicaris with further losses from attack by the tineid moth Heliostibes vibratrix. Growth and climatic data suggest decline was initiated by drought, with worst affected stands on sites with lowest soil moisture retention capability.

Arhopalus terus (Mulsant) female pupae and adults were dissected, and both internal and external genitalia are described. The external genitalia involve segments 8 and 9. Segment 9 and its appendag·es are modified into a long ovipositor whlich telescopes with segment 8 into segment 7 when retracted. The internal genitalia include ovaries, bursa copulatrix, spermatheca, spermathecal gland, vagina, and accessory glands. The terminology applied to coleopteran genital anatomy is critically discussed.