Aim To describe the coleopteran fauna occurring in canopies of temperate Gondwanan tree species in terms of their diversity and guild and taxonomic structures, and to test the proposition that this structuring reflects the Gondwanan origins of this fauna.Location The Andes and the coastal cordillera of temperate Chile.Methods Canopy fogging was used to sample beetles from 29 trees. The samples were statistically described using S chao and the Simpson diversity index D. Cluster analyses and multi-dimensional scaling (MDS) were performed. The taxonomic and guild structures of the Chilean coleopteran fauna were compared quantitatively with those found in other parts of the world using homogeneity chi-square and t-tests.Results A collection of 25,497 beetle specimens was obtained primarily from Nothofagus dombeyi, Nothofagus obliqua and Araucaria araucana. The specimens collected were distributed between 485 morphospecies and included 107 putative, new generic-level taxa and 223 apparently undescribed species. Estimates of the size of the canopy beetle fauna showed that 600+ species were likely to be present. The communities found on a tree species differed markedly between years. MDS plots showed less community divergence between tree species for predators than for phytophages and xylophages. The guild structure was similar to that found on Australian 'Gondwanan' trees but differed significantly from the community structures found on 'Laurasian' tropical and temperate trees in supporting fewer phytophages and saprophages, but more xylophages. The predator guild showed a different pattern, with tropical faunas differing from those of more temperate regions, irrespective of hemisphere, as did the distribution of superfamilies.Main conclusions The beetle fauna found in the canopies of N. dombeyi, N. obliqua and A. araucana was large (600+ species), with about half of the species undescribed. S chao was found to vary with sample size and to give lower estimates of S than species attenuation curves, raising the possibility that the two methods are estimating the sizes of different statistical communities. It is possible that the attenuation curve is estimating the number of species to be found on a particular tree species, while S chao is estimating the 'carrying capacity' for beetle species of individual trees, and this varies from tree to tree. Care also needs to be taken in experimental design when monitoring temporal changes in forest insect communities given the difference in communities found between years in this study. The proportions of phytophages, saprophages and xylophages resemble those of a 'Gondwanan' rain forest from Australia and differ significantly from those of tropical and temperate 'Laurasian' forests.

RESUMENLa ecología poblacional de los insectos de secano ha sido poco estudiada en Chile. Existen diferentes especies que habitan los interfluvios de la región desértico transicional que, bajo ciertas condiciones ambientales, irrumpen demográficamente. Una de estas especies es Elasmoderus wagenknechti (Orthoptera: Tristiridae). Esta es una especie endémica a Chile, su rango de distribución se extiende desde Taltal en la Segunda Región (25º22' S, 70º31' O) hasta Salamanca en la Cuarta Región (31º46'S, 70º58'O). En este trabajo se comunican y discuten los resultados de análisis morfométricos realizados en individuos adultos de E. wagenknechti. Estos fueron capturados durante dos eventos de irrupción poblacional ocurridos en 1996 y 1999 en la Cuarta Región (Coquimbo, Chile). Elasmoderus wagenknechti ha sido descrita como una especie braquíptera. En este estudio, la relación longitud del tegmen/longitud del abdomen fue 0,66 para el macho y 0,51 para la hembra. Para el ala metatorácica, esta relación fue 0,34 y 0,24 respectivamente. La variabilidad morfométrica de los 23 caracteres examinados resultó baja tanto en el macho (CV: 3,04-31,46 %) como en la hembra (3,68-32,00 %). A pesar del aspecto más grueso de la hembra, la relación ancho corporal/longitud total fue similar en ambos sexos (0,27). Del mismo modo, tanto en el macho como en la hembra, el nivel de hidratación bordeó el 71 % de la biomasa medida en fresco. En esta misma dirección, la relación biomasa seca/biomasa fresca fue similar en ambos sexos (e.g., 0,28 en el macho; 0,29 en la hembra). Las comparaciones morfométricas entre machos de diferente evento demográfico mostraron 10 diferencias significativas; las hembras, ocho diferencias. Además del tamaño (e.g., longitud total), el dimorfismo sexual quedó evidenciado en doce comparaciones morfométricas. La diferencia favoreció a la hembra en todos los casos. Los índices variable morfométrica / variable morfométrica más altos correspondieron al P s (2,83), L t (1,56), An mes (1,55) y L pn (1,52), todos ellos relacionados al tamaño. El índice de condición fue ligeramente más alto en la hembra (b 1 : 1,42) que en el macho (b 1 : 1,25). Aunque esta diferencia no resultó estadísticamente significativa, un valor mayor del índice de condición de las hembras sugeriría una mejor adecuación biológica de estas respecto de los machos. Esta habilidad de la hembras explicaría la capacidad de E. wagenknechti de irrumpir demográficamente en el semidesierto de Chile, una vez dadas las condiciones ambientales favorables para ello.Palabras clave: morfometría de insectos, insectos de secano, Orthoptera, irrupciones poblacionales. ABSTRACTThe population ecology of rangeland insects has been little studied in Chile. There are different species inhabiting the inter-valley areas of the transitional desert that, under certain environmental conditions, display population outbreaks. One of them is Elasmoderus wagenknechti (Orthoptera: Tristiridae). It is an endemic species to Chile. Its geographic range of distribution is from Taltal ...

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The Araucanía region is a berry producing area where important behavioral aspects of species in the genus Aegorhinus, a pest that affects crops, are still unknown. The objectives of this study were to determine the distribution, abundance and richness of these species in agroecological zones of La Araucanía Region and to determine the hosts in which they were found. The sites where these species were found were represented on a map divided into grids of 25 x 25 km. Eight species of Aegorhinus were found in the area, and Aegorhinus nodipennis and Aegorhinus superciliosus were the most abundant. The diversity was analyzed using the Shannon-Wiener index, and the equitability was determined using the Pielou index. The agroecological zone with the greatest diversity of the region corresponded to mountain ranges; however, the central plain registered the highest abundance of individuals. This study introduces new hosts for six of the eight species found in the region.