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A cladistic analysis of morphological characters of the subtribe Xyleborina (Curculionidae, Scolytinae) is presented. An examination of individual characters revealed little phylogenetic information in many characters currently used for delimiting genera. Phylogenetically stable characters were used for the evaluation of the contemporary generic concept. The following genera have been recovered as monophyletic: Cnestus, Dryocoetoides, Eccoptopterus, Xylosandrus, Schedlia, Sampsonius and Taurodemus. The following genera have been found to be polyphyletic: Amasa, Ambrosiodmus, Arixyleborus, Coptoborus, Coptodryas, Cryptoxyleborus, Cyclorhipidion, Euwallacea, Leptoxyleborus, Taphrodasus, Theoborus, Webbia, Xyleborinus and Xyleborus. The analysis permitted the resurrection of four genera: Anisandrus, Microperus, Pseudowebbia and Streptocranus. A number of new combinations at specific level are given: Anisandrus cornutus

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haplo-diploid, fungus-growing ambrosia beetles (Curculionidae: Scolytinae: Xyleborini) inferred from molecular and morphological data. -Zoologica Scripta, 40, 174-186. The ambrosia beetle tribe Xyleborini currently contains 30 genera and approximately 1200 species which are distributed throughout worldwide forests with most diversity located in the tropics. They also represent the most invasive scolytines in North America. Despite economic concerns and biological curiosity with this group, a comprehensive understanding of generic boundaries and the evolutionary relationship among species is lacking. In this study, we include 155 xyleborine species representing 23 genera in parsimony and Bayesian analyses using 3925 nucleotides from mitochondrial (COI) and nuclear genomes (28S, ArgK, CAD, EF-1a) and 39 morphological characters. The phylogenies resulting from the parsimony analyses, which treated gap positions either as missing or fifth character states, and the Bayesian analysis were generally similar. Clades with high support or posterior probabilities were found in all trees, while those with low support were not recovered by all analyses. Fourteen of the 23 genera were monophyletic although not all relationships among the genera were resolved. We show monophyly of several species groups associated with particular morphological and biological characters and suggest recognition of these groups as genera. Most interesting was the monophyly of South and Central American species representing several genera. This finding suggests recent and fast radiation of xyleborines in the New World accompanied by morphological and biological diversification.

Many ecological studies of tropical insects are based on small sample sizes or lack sampling scheme rigor, which prevents testing ecological hypotheses and comparing samples from different sites and times. Here we present the results of quantitative trapping of bark and ambrosia beetles over 2 yr at two localities in northern Thailand separated by 5 km, 1,100 m in altitude, and in different forest types. Beetles were collected using a spatially and temporally standardized sampling scheme, followed by a quantitative analysis of community composition and its responses to environmental variables and trapping techniques. In total, 118 species were collected, but the species accumulation curves show little sign of leveling off. Based on slightly different species accumulation rates, the more humid site has a little higher species richness. Species composition was significantly different between the sites, which was not a result of undersampling of rare species. alpha diversity at each site contributes to the regional diversity more than the turnover of species between the sites (beta diversity). Mean annual temperature and humidity have larger effects on the community species composition than seasonal fluctuations of temperature and humidity at each site--beetles do choose their environment but are aseasonal. The site with greater humidity supported significantly more species living in a symbiosis with fungi (ambrosia beetles), whereas the drier and more disturbed site hosted a greater number of circumtropical colonizer species. Each of the different types of trap had a bias for certain taxonomic groups. The results show that even modest samples, if properly structured and analyzed, can answer many ecological questions and can serve in biodiversity comparisons on broad scales.