Thermal tolerance and recovery behaviour of Thorectes lusitanicus (Coleoptera,Geotrupidae)

1. Population differences in physiological responses are examined in Thorectes lusitanicus, an endemic Iberian dung beetle species, by submitting individuals of different populations to the same experimental and acclimation conditions. 2. An infrared thermography protocol was used, consisting of three assays: start of activity, cold response, and heat response. Individuals of 12 populations were studied and the comparative explanatory capacities of several environmental factors in relation to the observed inter‐population differences were examined. 3. The heating rate from chill coma to the beginning of activity was the variable with the highest discrimination power among the studied populations, accounting for 94% of the observed variance. Regarding the heat response, only six of the 16 thermal variables reached significance (inter‐population differences accounted for 52–74% in these six thermal parameters). 4. From the three considered environmental factors (Mediterranean climate, land cover, and trophic characteristics) only land cover characteristics remain statistically significant, affecting the cold response of individuals. 5. Thorectes lusitanicus is a species characterised by a high diversity of thermotolerance and recovery traits across populations with a low degree of association with broad environmental factors. Finally, it is suggested that the apterous character of this species could be a determinant factor explaining the high diversity of ecophysiological traits related to thermal stress tolerance and the recovery time.     

Karyosystematic study of Potentilla L. subgen. Potentilla (Rosaceae) in the Iberian Peninsula

Chromosome numbers in 80 populations belonging to 18 species of Potentilla L. subgen. Potentilla from the Iberian Peninsula and two of P. maura, a North African endemic taxon, have been counted. The basic number of chromosomes is always x = 7 and these chromosomes are small (between 1 and 2 μm). For three species, the number of chromosomes is reported for the first time and, for another six, this number has been established in Iberian representatives. Moreover, new ploidy levels have been obtained for P. hispanica and P. crantzii with regard to their entire distribution area, and in P. cinerea and P. neumanniana for the Iberian Peninsula. Some taxonomic, phylogenetic and phytogeographic comments are made for several species or groups of species from the West Mediterranean region. In 13 species only one ploidy level has been found, but six species have several ploidy levels. Seven ploidy levels occur in the investigated taxa. The frequency of each ploidy level represented within Iberian Potentilla is analysed and the data are compared with those available for taxa from the rest of the distribution area of the genus.     

Diversity in Mediterranean farm ponds: trade‐offs and synergies between irrigation modernisation and biodiversity conservation

1. Agricultural intensification has caused dramatic biodiversity loss in many agricultural landscapes over the last century. Here, we investigated whether new types of farm ponds (made of artificial substrata) in intensive systems and natural‐substratum ponds in traditional farming systems differ in their value for aquatic biodiversity conservation. 2. We analysed the main patterns of environmental variation, compared α‐, β‐ and γ‐diversity of macroinvertebrates between ponds types and evaluated the role of submerged aquatic vegetation (SAV). Generalised additive models (GAM) were used to analyse the relationships of α‐ and β‐diversity with environmental predictors, and variation partitioning to separate the effect of environmental and spatial characteristics on the variation in macroinvertebrate assemblages. Moran’s eigenvector maps (MEMs) were used to define spatial variables. 3. A principal coordinate analysis (PCoA) detected a primary environmental gradient that separated nutrient‐rich ponds from those dominated by SAV; a secondary morphometric gradient distinguished natural‐substratum ponds, with large surface area and structural complexity, from artificial‐substratum ponds with steeper slopes. Natural‐substratum ponds had almost twice the α‐ and γ‐diversity of artificial‐substratum ponds, and diversity significantly increased when SAV was present, particularly in artificial‐substratum ponds. Total phosphorus (TP) strongly contributed to explain the patterns in diversity, while SAV was a significant predictor of assemblage composition and diversity. GAMs revealed optima of both α‐diversity at intermediate SAV covers and β‐diversity at intermediate–high TP concentrations. 4. These findings have important implications for conservation planning. Adaptation of artificial‐substratum ponds by adding natural substratum and smoothing the gradient of pond margins would improve their conservation value. Development of SAV with occasional harvests and certain cautionary measures to control nutrient levels may also improve both the agronomical and environmental function of ponds.     

Karyological and taxonomic notes on Ophrys (Orchidoideae, Orchidaceae) from the Iberian Peninsula

Karyological information on Iberian Ophrys species is very limited. This paper provides the haploid and diploid chromosome numbers of 11 taxa of sect. Pseudophrys and sect. Ophrys , both of which are well represented in the Iberian Peninsula, and two taxa from Tunisia. The first data on chromosome numbers for O. vasconica (2 n  = 72, 74), O. ficalhoana (2 n  = 36), O. picta (2 n  = 36), O. sphegifera ( n  = 18, 2 n  = 36, 38) and O. passionis (2 n  = 36) are also presented, confirming the stability of the chromosome number in Ophrys . In addition, populations of the group O. omegaifera ( O. dyris and O. vasconica ), together with tetraploidy, pentaploidy and the existence of aneuploid phenomena, are reported for the first time in Iberia. The basic diploid number is always 2 n  = 36. The karyotypes of several species were analysed. Evolutionary trends in Ophrys chromosomes are discussed. Taxonomic and phytogeographical details are provided on several species or groups of species from Iberia.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003 , 142 , 395−406.     

Effects of female feeding regime in a sexually cannibalistic mantid: fecundity,cannibalism, and male response in Stagmomantis limbata (Mantodea)

1. Female feeding regime exhibited a cascade of effects on reproductive biology and behaviour in the mantid Stagmomantis limbata (Hahn). 2. Well‐fed females (High diet) consistently attained greater body mass, thicker abdomens, and higher fecundity than food‐limited females (Low diet) in four annual generations. Dorso‐ventral abdominal thickness strongly correlated with fecundity. 3. In an experiment in captivity, Low diet females were more likely to cannibalize males than High diet females. 4. High diet females attracted more males than Low diet females in several contexts. In terms of long‐range attraction, caged High diet females attracted more males in the field. In terms of short‐range attraction, males preferentially mounted and copulated with High diet females in captive paired choice trials. In naturally‐occurring pairs in the field, a preference for females with thick abdomens was evident. These results point to two possible explanations: male choice for well‐fed females and state‐dependent female pheromone emission. 5. Two years of field data indicate considerable variation in female feeding success, as measured by abdominal thickness. Average feeding success in nature appears to be relatively high, when comparing the rate of abdominal expansion in the field to captive females maintained on High diets. 6. In the field, nearly all mounts and copulations occurred in September in both years, when female feeding success is expected to be high. If mating activity occurs during a window of high female feeding success, so as to reduce the risk of cannibalism for males, then the female feeding regime may be implicated in the phenology of mating activity in cannibalistic species.