| Abstrakt: |
Abstract: When environmental conditions become unfavourable most invertebrates enter into a state of reduced activity called dormancy. In ladybird beetles dormancy usually occurs in the adult stage and in many species takes up most of their lifespan. In this review, some ecological and behavioural issues related to dormancy, such as habitat selection, migration to dormancy sites, aggregation, mortality, phenology and species composition of aggregations of ladybirds in hibernation are discussed. The habit of migrating to and hibernating in high mountains is characteristic of many ladybirds and is here discussed in detail with its advantages and disadvantages highlighted. The latter include the high energy cost of migrating to and dispersing from mountain sites, high mortality often recorded in ladybird aggregations on mountain tops and phenological shifts that result in a considerable curtailment of the periods suitable for reproduction, development and accumulation of metabolic reserves compared to those of ladybirds that enter dormancy in the lowlands. Knowledge of the dormancy ecology of Coccinellidae largely relies on studies of a few species, such as Coccinella septempunctata Linnaeus, 1758, Ceratomegilla undecimnotata (Schneider, 1792) and Hippodamia convergens Guérin-Méneville, 1842. It is postulated that investigating other species, especially those that are more ecologically specialized, will reveal more dormancy-related strategies and provide a better insight into ladybird ecology. It is also emphasized that the use of a community approach when studying ladybird dormancy will provide valuable information, both in terms of basic knowledge and its applications (e.g. pest management, conservation of rare species). |
