We compared plant and caterpillar data to examine the effect of forest types on patterns in species diversity across forest succession gradients. We test the hypotheses that the differences in species diversity gradually increase from young to old-growth forests, that the differences among forest habitats gradually increase from dry to humid forest types, and that caterpillar diversity patterns along these environmental gradients are consistent throughout the year. Particularly in the transitional and humid forest types, species numbers of woody plants reaching the understorey and canopy layers were lowest in secondary forests, while partitioning and canonical analyses demonstrated major effects of forest types on species turnover across successional gradients. Contrastingly, for caterpillars at a yearly base and small plants in the undergrowth, species numbers were often, although rarely significantly higher in young successional vegetation, whereas the variation in species turnover was strongly driven by the individual factor of forest types. Correlations between caterpillar and plant community similarities presented no gradual changes along environmental gradients. Caterpillar community structure at yearly base comprised high seasonal variability, leading to inconsistent diversity patterns along environmental gradients for individual seasons. Overall, the results suggested a faster but also distinct development of post-disturbance recovery of plant species diversity in the driest forest type, compared to more humid forests. The variation in caterpillar species diversity appears mostly influenced by seasonal cues, by regional species turnover of undergrowth plants, and to a lesser extent by patterns of local species diversity of undergrowth plants along forest succession.