ABSTRACT
BACKGROUND: The checklist of British and Irish aculeate Hymenoptera (Apoidea, Chrysidoidea and Vespoidea) is revised. Species distribution is summarised for all species at the level of country (England, Scotland, Wales, Ireland and Isle of Man). NEW INFORMATION: The 601 native species represent an increase of 25 on the 1978 checklist, comprising mostly new discoveries. This increase is nearly balanced by the 23 species now presumed to be extinct in Britain and Ireland.
ABSTRACT
Very large colonies of territorially dominant arboreal ants (TDAAs), whose territories are distributed in a mosaic pattern in the canopies of many tropical rainforests and tree crop plantations, have a generally positive impact on their host trees. We studied the canopy of an old Gabonese rainforest (ca 4.25 ha sampled, corresponding to 206 "large" trees) at a stage just preceding forest maturity (the Caesalpinioideae dominated; the Burseraceae were abundant). The tree crowns sheltered colonies from 13 TDAAs plus a co-dominant species out of the 25 ant species recorded. By mapping the TDAAs' territories and using a null model co-occurrence analysis, we confirmed the existence of an ant mosaic. Thanks to a large sampling set and the use of the self-organizing map algorithm (SOM), we show that the distribution of the trees influences the structure of the ant mosaic, suggesting that each tree taxon attracts certain TDAA species rather than others. The SOM also improved our knowledge of the TDAAs' ecological niches, showing that these ant species are ecologically distinct from each other based on their relationships with their supporting trees. Therefore, TDAAs should not systematically be placed in the same functional group even when they belong to the same genus. We conclude by reiterating that, in addition to the role played by TDAAs' territorial competition, host trees contribute to structuring ant mosaics through multiple factors, including host-plant selection by TDAAs, the age of the trees, the presence of extrafloral nectaries, and the taxa of the associated hemipterans.
Subject(s)
Ants/physiology , Territoriality , Trees , Animals , Models, Biological , Population Dynamics , Social Behavior , Tropical ClimateABSTRACT
The monophyletic group of myrmicine ant genera related to Eutetramorium is described and its taxonomy is documented. The group is endemic in Madagascar and contains five genera: Eutetramorium Emery, 1899 (3 species, 1 of which is new); Malagidris nom. n., a replacement name for Brunella Forel, 1917, junior homonym of Brunella Smith, G.W. 1909 (Crustacea) (6 species, 5 of which are new); Myrmisaraka gen. n. (2 species, both new); Royidris gen. n. (15 species, 11 of which are new); Vitsika gen. n. (14 species, all of which are new). Keys to the worker caste are provided for all genera, and provisional keys to known males are given for Malagidris and Vitsika.
