Luis F. Valladares

Seasonal dispersal of water beetles (Coleoptera) in an agricultural landscape: a study using Moericke traps in northwest Spain

Abstract Information on flight dispersal in water beetles in the Iberian Peninsula is scarce. This study provides new data on the dispersion flight phenology of 21 species captured using Moericke traps in an agricultural system in León province (NW Spain) during two annual cycles (1992 and 1993). The species captured form part of the assemblage of aquatic Coleoptera commonly found in stagnant environments in the centre of the Iberian Peninsula. Most of them are good flyers and colonisers. These flights are related to two environmental variables: mean atmospheric temperature and rainfall. The results show a clear relation between temperature and the flight period as most of the specimens dispersed during peaks of high mean daily temperatures, and a negative relation with rainfall. With regard to phenology, two types of dispersion strategy were identified: flights in the middle of summer to escape from drought and flights in spring and autumn for colonising new habitats. The first group includes Hydroglyphus geminus (Fabricius) and, in particular, Helophorus brevipalpis Bedel, whose great abundance in the dispersal stage is related to parthenogenetic reproduction and the rapid production of a large number of colonising females. The second strategy corresponds to univoltine species with overwintering adults such as Helophorus alternans Gené or species from the genus Hydroporus Clairville.

Morphological reply to a DNA call: a new cryptic species of Hydraena from western Europe, with a complete overview of the Hydraena gracilis complex (Coleoptera: Hydraenidae: “Haenydra” lineage)

Recent molecular analyses revealed unexpected genetic variability within Hydraena gracilis, one of the most common and widespread European moss beetles, belonging to the West Palaearctic endemic “Haenydra” lineage. For this taxon, molecular data univocally evidenced two distinct clades, the first one including populations from the Iberian Peninsula, and the second including populations from central and eastern Europe. Aedeagal morphology of H. gracilis was further investigated, finally demonstrating the actual existence of a new cryptic species of the H. gracilis complex in Portugal, Spain and the French Pyrenees. The geographical range of the true H. gracilis was consequently revised. Finally, dichotomous keys for males of all species belonging to the H. gracilis complex, and for males of all the Iberian “Haenydra” species, are also supplied.

Diversity of Water Beetles in Picos de Europa National Park, Spain: Inventory Completeness and Conservation Assessment

ABSTRACT The diversity of true water beetles (Coleoptera: Gyrinidae, Haliplidae, Dytiscidae, Helophoridae, Hydrochidae, Hydrophilidae, Hydraenidae, Elmidae, and Dryopidae) in Picos de Europa National Park (Cantabrian Mountains, Spain) was examined. Taking into account historic long-term sampling (all collections from 1882 to the present), a total of 117 species are recorded. Species accumulation models and non-parametric estimators were used to estimate the actual species richness of aquatic Coleoptera occurring in Picos de Europa National Park. Estimates were generated by analyzing both the collectors curve from the long-term sampling and the historic cumulative curve of species recorded from the park since 1882. Values of species richness estimated by different methods range from 127 to 170 species (mean = 148 ± 15 SD). Therefore, it seems that the current inventory has reached a reasonably good level of completeness as estimates indicate that about 80% of the water beetle fauna has already been recorded. The inventory is used to analyze the biological uniqueness of the park and its outstanding level of species richness and endemism (33 Iberian endemic species). Richness and endemism of water beetles in Picos de Europa National Park is compared to those of other national parks in Spain. Finally, the conservation status and threat level is assessed for two Cantabrian endemic species, Deronectes costipennis gignouxi Fery and Brancucci and Ochthebius (Asiobates) cantabricus Balfour-Browne.

Limnebius minoricensis sp. n. (Coleoptera: Hydraenidae) from the Balearic Islands, Spain

Limnebius minoricensis from Menorca (Spain, Balearic Islands) is described. Phylogenetically, the new species belongs to the Limnebius nitidus group (L. cordobanus subgroup).

A molecular phylogeny of the tribe Ochthebiini (Coleoptera, Hydraenidae, Ochthebiinae): Phylogeny of Ochthebiini

Ochthebiinae, with c. 650 species distributed worldwide, are the second most speciose subfamily of the aquatic beetle family Hydraenidae. They are ecologically the most diverse hydraenid subfamily, with terrestrial species as well as species in almost all types of aquatic habitats, including hypersaline waters. Ochthebiinae include the tribes Ochtheosini (four species in three genera) and Ochthebiini. We provide here the first comprehensive phylogeny of the tribe Ochthebiini, based on 186 species and four subspecies from most genera, subgenera and species groups. We obtained sequence data for a combination of mitochondrial and nuclear gene fragments including the 5′ and 3′ ends of the cytochrome c oxidase subunit 1, the 5′ end of 16S RNA plus the leucine tRNA transfer plus 5′ end of NADH dehydrogenase subunit I, and internal fragments of the large and small ribosomal units. The analyses with maximum likelihood (ML) and Bayesian probabilities consistently recovered a generally well supported phylogeny, with most currently accepted taxa and species groups as monophyletic. We provide a new classification of the tribe based on our phylogenetic results, with six genera: Meropathus Enderlein, Ochthebius Leach, Protochthebius Perkins, Prototympanogaster Perkins, Tympallopatrum Perkins and Tympanogaster Janssens. The genus Ochthebius is here divided into nine subgenera in addition to Ochthebius s.s.: (1) O. (Angiochthebius) Jäch & Ribera; (2) O. (Asiobates) Thomson; (3) O. (Aulacochthebius) Kuwert; (4) O. (Cobalius) Rey; (5) O. (Enicocerus) Stephens; (6) O. (Gymnanthelius) Perkins comb.n.; (7) O. (Gymnochthebius) Orchymont; (8) O. (Hughleechia) Perkins comb.n.; and (9) O. (Micragasma) Sahlberg. Within Ochthebius s.s., 17 species groups are proposed, five of them newly established (3, 9, 11, 13 and 16): (1) andraei; (2) atriceps; (3) corrugatus; (4) foveolatus; (5) kosiensis; (6) lobicollis; (7) marinus; (8) metallescens; (9) nitidipennis; (10) notabilis; (11) peisonis; (12) punctatus; (13) quadricollis; (14) rivalis; (15) strigosus; (16) sumatrensis; and (17) vandykei. We elevated to species rank two subspecies of Ochthebius: O. fallaciosus Ganglbauer stat.n. (former subspecies of O. viridis Peyron) and O. deletus Rey stat.rest. (former subspecies of O. subpictus Wollaston).

Diet Selection of the Aquatic Warbler Acrocephalus paludicola During Its Post-Nuptial Migration Stopover in NW Spain

Food availability and diet are two key issues in understanding the ecological requirements of a migratory species in stopover sites and in taking effective conservation measures. In the case of the globally threatened Aquatic Warbler, there have previously been no studies examining diet selection in the Iberian Peninsula, a key region for their post-nuptial movements. In this context, the availability of arthropods in different habitats (reeds, rushes and grassland), the composition and biomass of prey in faecal samples, and diet selection were all investigated in a wetland in northwest Spain. The results showed a higher total abundance of arthropods in grassland and rushes: habitats which were more similar to each other, in terms of vegetation physiognomy and composition of invertebrates, compared with reeds. In terms of prey abundance, diet was dominated by Araneae, Heteroptera and Homoptera. However, the groups that contributed most to the ingested biomass were Diptera (Tipulidae), Odonata and Orthoptera, followed by Araneae. Prey selection indices showed a preference for these groups, which all contain insects with a large body length. These diet characteristics showed many similarities with studies in other stopover and breeding areas, but differ in that Araneae were the main arthropod prey at this stopover site.